A number of significant scientific events occurred in2019.

• 1 January – TheNew Horizonsspace probe flies byKuiper belt object486958 Arrokoth (nicknamedUltima Thule), the outermost close encounter of anySolar System object.^[2][3][4]
• 2 January – A study finds that tons ofmethane, agreenhouse gas, are released into the atmosphere by melting ice sheets inGreenland.^[5]
• 3 January
  • China's National Space Administration (CNSA) achieves the firstsoft landing on thefar side of the Moon with itsChang'e 4 mission.^[6]
  • Scientists report the engineering of crops with aphotorespiratory "shortcut" to boostplant growth by 40% in real-world agronomic conditions.^[7][8]
• 4 January
  • Researchers atEcole polytechnique fédérale de Lausanne (EPFL) report a way to control properties ofexcitons and change thepolarisation of light they generate, which could lead totransistors that undergo less energy loss andheat dissipation.^[9]
  • Researchers design an inhalable form ofmessenger RNAaerosol that could be administered directly to thelungs to help treat diseases such ascystic fibrosis.^[10]
• 6 January
  • Apartial solar eclipse occurred.
• 8 January
  • Researchers from the U.S. Department of Energy'sPrinceton Plasma Physics Laboratory (PPPL) report a new way to stabilise the "tearing modes" infusion reactors, usingradio waves to create small changes in the temperature of theplasma, allowing it to be controlled more easily.^[11]
  • IBM unveilsIBM Q System One, its first integratedquantum computing system for commercial use.^[12][13]
• 9 January
  • Astronomers announce the discovery of a second repeatingfast radio burst (FRB) source, namedFRB 180814.^[14][15]
  • The firstSD card with a storage capacity of 1terabyte (TB) is announced byLexar.^[16]
  • Astronomers at theUniversity of Warwick present the first direct evidence ofwhite dwarf stars solidifying intocrystals.^[17]

• 10 January – Astronomers propose thatAT2018cow, avery powerful astronomical explosion, 10–100 times brighter than a normalsupernova, may have been awhite dwarf being pulled apart by ablack hole; or, a supernova leaving behind a black hole or aneutron star, the creation of a compact body being observed for the first time.^[19][20][21]
• 11 January – Researchers at theUniversity of Michigan demonstrate a new approach to3D printing, based on the lifting of shapes from a vat of liquid, which is up to 100 times faster than conventional processes.^[22]
• 14 January – A study in the journalPNAS finds thatAntarctica experienced a sixfold increase in yearly ice mass loss between 1979 and 2017.^[23]
• 16 January – A study inEcological Monographs suggests there may be sustained foraging specialization, fasting and omnivory in thewhale shark (Rhincodon typus), the world's largest fish.^[24]
• 17 January
  • Scientists report thatAustralopithecus sediba is distinct from, but shares anatomical similarities to, both the olderAustralopithecus africanus, and the youngerHomo habilis.^[18]
  • Astronomers report that aday on the planetSaturn has been determined to be10^h 33^m 38^{s+ 1m 52s}
    _{− 1^m 19^s} , based on studies of the planet'sC Ring.^[25][26]
• 21 January
  • Scientists report that theGreenland ice sheet is melting four times faster than in 2003, with its largest sustained ice loss coming from the southwest region.^[27]
  • Lunar eclipse
• 22 January – Alphabet'sWaymo subsidiary announces that it will later in 2019 begin construction in the US State of Michigan on the World's first factory for mass-producing autonomous vehicles.^{[28][29][30][31]}
• 23 January
  • Scientists in China report the creation of five identicalclonedgene-editedmonkeys, using the same cloning technique that was used withZhong Zhong and Hua Hua – the first-ever cloned monkeys – andDolly the sheep, and the same gene-editingCRISPR-Cas9 technique allegedly used byHe Jiankui in creating the first-ever gene-modified human babiesLulu and Nana. The genetically modified monkey clones were made in order to study several medical diseases.^[32][33][34]
  • Astronomers report the first-ever detection ofglycolonitrile, another possiblebuilding block of life amongother such molecules, inouter space.^[35]

• 24 January
  • NASA announces that theOpportunity rover has been on the planetMars for 15 years.^[36][37]
  • NASA scientists report the discovery of theoldest known Earth rock – on theMoon.Apollo 14astronauts returned several rocks from theMoon and later, scientists determined that a fragment from one of the rocks contained "a bit of Earth from about 4 billion years ago." The rock fragment containedquartz,feldspar, andzircon, all common on the Earth, but highly uncommon on the Moon.^[38]
  • The completeaxolotl genome is reported to have been sequenced by the University of Kentucky.^[39][40]
• 25 January – AlphaStar, a new artificial intelligence algorithm byAlphabet'sDeepMind subsidiary, defeats professional players of the real-time strategy gameStarCraft II in ten rounds out of eleven.^[41][42][43]
• 29 January – Researchers atPurdue University'sCollege of Engineering release a paper in the journalACS Sustainable Chemistry & Engineering detailing a new process to turnplastic waste in hydrocarbon fuels.^[44][45][46]
• 30 January – Scientists report that several types of humans, includingDenisovans,Neanderthals andrelated hybrids, may have inhabited theDenisova Cave inSiberia over thousands of years, but it is unclear whether they ever shared the cave.^[47]
• 31 January
  • Researchers at theUniversity of California, Berkeley, demonstrate a new form of3D printer, which uses light exposure to transform a viscous liquid into complex solid objects.^[48]
  • A new AI developed by RMIT atUniversity of Melbourne and trained to play the 1980s video gameMontezuma's Revenge is reported to be 10 times faster thanGoogle DeepMind and able to finish the game.^[49]

• 1 February – NASA scientistsreport that theMarsCuriosity rover determined, for the first time, thedensity ofMount Sharp inGale crater, thereby establishing a clearer understanding of how the mountain was formed.^[52][53]
• 3 February – Medical scientists announce thatiridium attached toalbumin, creating aphotosensitized molecule, can penetratecancer cells and, after being irradiated with light (a process calledphotodynamic therapy), destroy the cancer cells.^[50][51]
• 4 February – A study by theInternational Centre for Integrated Mountain Development concludes that 36% of glaciers along theHindu Kush andHimalaya range will disappear by 2100, even ifcarbon emissions are cut rapidly. Without emission reductions, the loss could reach two-thirds.^[54][55]
• 5 February – NASA reports that the two small communicationCubeSats, that accompanied theInSight lander to the planetMars, went silent, and are unlikely to be heard from again.^[56]
• 6 February
  • NASA and NOAA confirm that 2018 was the fourthhottest year on record globally, at 0.83 degrees Celsius (1.5 degrees Fahrenheit) above the 1951 to 1980 mean.^[57]
  • Scientists from theInstituto de Astrofísica de Canarias publish the first evidence of a collision betweenexoplanets, which is believed to have occurred in theKepler-107 system, approximately 1,670light years from Earth.^[58]
• 7 February
  • Medical scientists working withSangamo Therapeutics, headquartered inRichmond, California, announce the first-ever "in body"human gene editing therapy to permanently alterDNA in a patient withHunter syndrome.^[59]Clinical trials bySangamo Therapeutics involving gene editing usingZinc Finger Nuclease (ZFN) are ongoing.^[60]
  • The ExoMars rover, scheduled to launch in July 2020 and search for theexistence of past life on theplanet Mars, has been officially named theRosalind Franklin rover afterDNA pioneerRosalind Franklin.^[61]
  • Scientists announce the discovery of a new type ofmagnet that might benefit the performance ofdata storage technologies.^[62]

• 8 February – NASA scientists, studying the latest returned images and data, report that486958 Arrokoth, the remoteKuiper Belt Object visited by theNew Horizons spacecraft, was determined to be more flattened than thought earlier; and has been described to be more like a large "pancake" (larger lobe) and a "walnut" (smaller lobe), rather than twoellipsoids.^[1][65]
• 11 February – Scientists find evidence, based ongenetics studies usingartificial intelligence (AI), that suggest the existence of an unknown human ancestor species, notNeanderthal,Denisovan or human hybrid (likeDenny (hybrid hominin)), in thegenome ofmodern humans.^[66][67]
• 13 February – NASA officials declare that the Mars roverOpportunity has ended its mission, after failing to respond to repeated transmitted wake-up signals. Its last contact was on 10 June 2018 (Click here for the last panorama image.)^[63][64]
• 18 February
  • A British woman becomes the first person in the world to havegene therapy forage-related macular degeneration (AMD).^[68]
  • Scientists use gene therapy to restore hearing in an adult mouse model of DFNB9 deafness.^[69]
• 19 February
  • Researchers atOxford Martin School publish evidence that, in the longer term, some forms ofcultured meat could be worse for the environment than traditional farmed meat.^[70][71]
  • Scientists report evidence, based onisotope studies, that at least someNeanderthals may have eatenmeat.^[72][73][74]

• 21 February
  • Scientists announce a new form ofDNA, namedHachimoji DNA, composed of four natural, and four unnaturalnucleobases. Benefits of such an eight-base DNA system may include an enhanced ability tostore digital data, as well as insights into what may be possible in the search forextraterrestrial life.^[75][76]
  • Scientists report that the purportedly first-evergermlinegenetically edited humans, the twin babiesLulu and Nana, by Chinese researcherHe Jiankui, may have inadvertently (or perhaps, intentionally^[77]) had theirbrains enhanced.^[78]
  • SpaceX launchesSpaceIL'sBeresheet probe, the world's first privately financed mission to theMoon.^[79][80]
  • Astronomers led byScott S. Sheppard announce the discovery ofFarFarOut, the most distant object yet found in the Solar System, at an estimated distance of 140 AU (21 billion km) from the Sun.^[81]
• 25 February
  • Scientists report evidence thatNeanderthals walked upright much like modern humans.^[82][83]
  • The firstmicroSD card with a storage capacity of 1terabyte (TB) is announced byMicron.^[84]
• 26 February – Researchers atRMIT University demonstrate a method of using a liquid metalcatalyst to turncarbon dioxide gas back intocoal, potentially offering a new way to store carbon in solid form.^[85]
• 28 February
  • Scientists report the first-ever evidence of a formerplanet-wide groundwater system on the planetMars.^[86][87]
  • Scientists report the creation of mice withinfrared vision, using nanoparticles injected into their eyes.^[88]

• 3 March – An uncrewed demonstration flight of the new crew capable version of theSpaceXDragon spacecraft, intended to carry American astronauts into space, achieves successful autonomous docking with theInternational Space Station.^[89] It returned to Earth a few days later.^[90]

• 4 March – Scientists report thatasteroids may bemuch more difficult to destroy than thought earlier.^[92][93] In addition, an asteroid may reassemble itself due togravity after being disrupted.^[94]
• 5 March
  • A second case of sustained remission fromHIV-1 is reported, ten years after the 'Berlin Patient.'^[95][96]
  • Astronomers report the discovery of unusual dimming inEPIC 204376071, a star that has been observed to dim in brightness by up to 80%, much more deeply than the 22% dimming ofTabby's star.^[97][98][99]
• 7 March – Researchers at theMassachusetts Institute of Technology (MIT) demonstrate a new optical imaging system that could enable the discovery of tiny tumours, as small as 200 cells, deep within the body.^[100]
• 8 March – Astronomers report that themass of theMilky Waygalaxy is 1.5 trillionsolar masses within aradius of about 129,000light-years, over twice as much as was determined in earlier studies, and suggesting that about 90% of the mass of the galaxy isdark matter.^[101][102]
• 11 March – A team ofJapanese andRussian scientists report that cell nuclei fromwoolly mammoth remains showed biological activity when transplanted into mouse cells.^[91]
• 13 March – The laser of ELI-NP inMăgurele, part of theEuropean ELI Project, becomes the most powerful laser system ever made, reaching a peak power of 10Petawatts.^[103]
• 15 March – NASA reports that latentviruses in humans may be activated duringspace missions, adding possibly more risk to astronauts in futuredeep-space missions.^[104]

• 16 March – NASA announces that a 173-kiloton fireball (theKamchatka meteor) fell over theBering Sea near theKamchatka Peninsula on 18 December 2018, the second largest asteroid to hit Earth in 30 years, after theChelyabinsk meteor.^[107] (seeimage)
• 18 March
  • Researchers provide supporting evidence, based ongenetic studies, thatmodernHomo sapiens, arose first inSouth Africa more than 300,000 years ago, traveled toEast Africa, and from there, about 60,000 years ago, traveledout of Africa to the rest of the world.^[108][109]
  • PhysicistAdrian Bejan presents an explanation of whytimeseems shorter as we get older, which can be attributed to "the ever-slowing speed at which images are obtained and processed by the human brain as the body ages."^{[110][111][112]}
• 19 March
  • Karen Uhlenbeck is reported to be the first woman to receive the prestigiousAbel Prize in Mathematics.^[113][114]
  • Astronomers describe scenarios wherecarbon monoxide may be abiosignature for a thriving community ofextraterrestrial life on other worlds.^[115]
• 20 March – Paleontologists report the discovery ofAvimaia schweitzerae, the firstfossil bird found with anunlaid egg, that lived about 115 million years ago inNorthwest China.^[105][106]
• 27 March
  • Scientists report thatlife-forms from Earth survived 18 months living inouter space outside theInternational Space Station (ISS), as part of theBIOMEX studies related to theEXPOSE-R2 mission, suggesting that life could survive, theoretically, on theplanet Mars.^[116][117]
  • ESO astronomers, employing theGRAVITY instrument on theirVery Large Telescope Interferometer (VLTI), announce the firstdirect detection of anexoplanet,HR 8799 e, usingoptical interferometry.^[118]
  • Chinese scientists report inserting the human brain-relatedMCPH1 gene into laboratoryrhesus monkeys, resulting in the transgenic monkeys performing better and answering faster on "short-term memory tests involving matching colors and shapes", compared to control non-transgenic monkeys, according to the researchers.^[119][120]
• 28 March
  • Researchers report the possibility ofancient life on theplanet Mars based on microscopic studies of theAllan Hills 77005 (ALH-77005)Martian meteorite found on Earth.^[121][122]
  • Scientists report evidence that suggests theplanet Mars, in some near-equatorial regions, currently contains adeep groundwater system.^[123][124]
  • APew Research Center study (4464 adults; mid-January 2019) onscientific knowledge amongAmericans finds substantial differences based onformal education level (higher is better),race andethnicity (whites higher) andgender (males higher). No substantial differences were found based onpolitical affiliation.^[125]
• 29 March – Paleontologists describe a site called Tanis, in North Dakota'sHell Creek Formation, containing animal and plant fossils dated to65.76 million years BCE. These remains are embedded with tiny rock and glass fragments that fell from the sky in the minutes and hours following theChicxulub impact. The deposits also show evidence of having been swamped with water, caused by the subsequentmegatsunamis.^[126][127]

• 1 April
  • Scientists report confirming the presence ofmethane on theplanet Mars, and determining that the source of the methane likely came from an ice sheet about 300 miles east ofGale Crater. TheCuriosity rover is currently exploring Gale Crater.^{[132][133][134]}
  • Scientists atETH Zurich report the creation of the world's firstbacterial genome, namedCaulobacter ethensis-2.0, made entirely by a computer, although a related viable form ofC. ethensis-2.0 does not yet exist.^[135][136]
• 4 April – NASA releases animated images ofsolar eclipses by thetwo moons of the planet Mars,Deimos (animation1/17 March 2019) andPhobos (animation2/27 March 2019), asviewed by theCuriosity rover on theplanet Mars in March 2019.^[137][138]
• 7 April – NASA reports that a comprehensive study ofmicroorganisms andfungi present on theInternational Space Station has been conducted. The results can be useful in improving health and safety conditions forastronauts.^[139][140]
• 10 April – Scientists from theEvent Horizon Telescope project announce the first-ever image of ablack hole, located 54 million light years away in the centre of theM87 galaxy.^{[128][129][130][131]}
• 10 April
  • Scientists find a way to view reactions in "dark states" of molecules, i.e. those states that are normally inaccessible.^[141]
• 11 April
  • NASA announces that theCuriosity rover on the planetMars drilled into, and closely studied, a "clay-bearing unit" which, according to the rover Project Manager, is a "major milestone" inCuriosity's journey upMount Sharp.^[142] (related image)
  • The IsraeliBeresheet probe crashes on the Moon after a technical glitch causes its main engine to switch off.^[143]

• 12 April – NASA reports medical results, from anAstronaut Twin Study, where oneastronauttwin spent a year in space on theInternational Space Station, while the other twin spent the year onEarth, which demonstrated several long-lasting changes, including those related to alterations inDNA andcognition, when one twin was compared with the other.^[146][147]
• 16 April – Scientists report, for the first time, the use of theCRISPR technology to edithuman genes to treatcancer patients with whom standard treatments were not successful.^[148][149]
• 17 April – After a long search, astronomers report the detection ofhelium hydride, a primordial molecule thought to have been formed about 100,000 years after theBig Bang, for the first time inouter space inNGC 7027.^[150][151]
• 23 April – NASA reports that the MarsInSight lander detected its firstMarsquake on theplanet Mars.^[152][153] (related AudioVideo file)
• 24 April – TheXENONdark matter project announces that it has observed the radioactive decay ofxenon-124, which has a half-life of 1.8sextillion years.^[154][155]
• 25 April – Astronomers report further substantial discrepancies, depending on the measurement method used, in determining theHubble constant, suggesting a realm of physics currently not well understood in explaining the workings of theuniverse.^{[156][157][158][159][160]}
• 29 April – Scientists, working with theHubble Space Telescope, confirmed the detection of the large and complex ionized molecules ofbuckminsterfullerene (C₆₀) (also known as "buckyballs") in theinterstellar medium spaces between thestars.^[144][145]
• 30 April – Biologists report that the very largemedusavirus, or a relative, may have been responsible, at least in part, for theevolutionary emergence of complexeukaryotic cells from simplerprokaryotic cells.^[161]

• 1 May – A study by U.S. researchers finds that deleting the ATDC gene can prevent the growth ofpancreatic cancer in mice.^[165]
• 2 May
  • Astronomers, from theHubble Space Telescope, release theHubble Legacy Field Zoom Out (video; 00:50), a 16-year effort, which provides a zoom out view from theUltra Deep Field of galaxies to the Legacy Field of galaxies.^[166]
  • A study of nearly 1,000 gay male couples who tookantiretroviral therapy, published inThe Lancet, finds no cases ofHIV transmission over eight years.^[167][168]
• 3 May – The UK'sNational Nuclear Laboratory (NNL) andUniversity of Leicester report the first generation of usable electricity fromamericium, which could lead to the development of "space batteries" that power missions for up to 400 years.^[169][170]
• 6 May
  • In its first report since 2005, theIntergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) warns thatbiodiversity loss is "accelerating", with over a million species now threatened withextinction; the decline of thenatural living world is "unprecedented" and largely a result of human actions.^{[162][163][164]}
  • Researchers atColumbia University report a newdesalination method forhypersaline brines, known as "temperature swing solvent extraction (TSSE)", which is low-cost and efficient.^[171]
• 8 May – A British teenager, Isabelle Holdaway, 17, is reported to be the first patient to receive a genetically modifiedphage therapy to treat adrug-resistant infection.^[172][173]
• 11 May – Atmospheric CO₂, as measured by theMauna Loa Observatory, Hawaii, reaches 415 parts per million (ppm), the highest level for 2.5 million years.^[174][175] During the latePliocene,sea levels were up to 20 m higher, and theglobal climate was 3 °C hotter.
• 14 May
  • Computer security researchers atGraz University of Technology andCatholic University of Leuven, in acoordinated disclosure withIntel, announce the discovery of a group ofMicroarchitectural Data Sampling vulnerabilities, affecting millions ofIntel microprocessors, which they named Fallout, RIDL (Rogue In-Flight Data Load) and ZombieLoad.^[176]
  • Researchers atMicrosoft reported theBlueKeepsecurity vulnerability (CVE-2019-0708) (noted as"critical" by Microsoft) that may affect nearly one million computers usingolder versions (Windows 8 andWindows 10 arenot affected) of theWindowsoperating systems with a "wormable"Remote Desktop Services (RDS)Remote Code Execution (RCE)Remote Desktop Protocol (RDP) vulnerability. Microsoft recommends installing available update patches as soon as possible, and also recommends turning off Remote Desktop Services if they are not required.^{[177][178][179][180]}
  • Researchers atMacquarie University report thatplastic pollution is harming the growth,photosynthesis and oxygen production ofProchlorococcus, the ocean's most abundant photosynthetic bacteria, responsible for 10% of oxygen breathed by humans.^[181]

• 15 May
  • Researchers, in a milestone effort, report the creation of a newsynthetic (possiblyartificial) form ofviablelife, a variant of thebacteriaEscherichia coli, by reducing the natural number of 64codons in the bacterialgenome to 59 codons instead, in order to encode 20amino acids.^[182][183]
  • Researchers atUniversity of Nebraska Medical Center describe the role of TGF-beta type II signaling receptor (TGFBR2) inosteoarthritis, which plays a key role in the progression of the disease by regulating joint development. They also identify a potential new drug that could treat it.^[184]
• 16 May
  • Astronomers report their first results about486958 Arrokoth, theKuiper Belt object in theouter Solar System that theNew Horizonsspace probe flew by in January 2019.^[185][186]
  • Researchers from the University of Leeds report that nearly a quarter of theWest Antarctic Ice Sheet is now unstable, with melting of thePine Island andThwaites glaciers now five times faster than 25 years previously.^[187][188]
• 19 May
  • Researchers at the University of Melbourne report an unusual slowdown in the growth oflife expectancy in Australia, following 20 years of rapid increases.^[189][190]
  • Physicists report that decay processes ofquasiparticles in certain strongly interacting medium systems may be stopped entirely, which may help make such particles basically immortal.^[191][192]
• 20 May
  • Lawyers inChina report, in light of the purported creation by Chinese scientistHe Jiankui of thefirst gene-edited humans (seeLulu and Nana controversy), the drafting of regulations that anyone manipulating thehuman genome bygene-editing techniques, likeCRISPR, would be held responsible for any related adverse consequences.^[193]
  • Therevision of theSI system of measurement adopted by the majority of countries in the world takes effect.^[194]

• 21 May – Researchers atMcMaster University report the discovery of a new and more efficient method of storing vaccines in temperatures of up to 40 °C for weeks at a time.^{[198][199][200]}
• 22 May
  • Scientists report the discovery of afossilizedfungus, namedOurasphaira giraldae, in theCanadian Arctic, that may have grown on land a billion years ago, well beforeplants were living on land.^{[195][196][197]}
  • Superconductivity at very high pressure is observed at a temperature of −23 °C (−9 °F), a jump of about 50 degrees compared to the previous confirmed record, by researchers at theUniversity of Chicago.^[201][202]
• 23 May
  • Researchers at the University of Southampton predict that the average (median) body mass ofmammals will collectively reduce by 25 per cent over the next century, due to the impact of human activity.^{[203][204][205]}
  • Astronomers report the discovery of avery large amount of water in thenorthern polar region of theplanet Mars.^[206][207]
• 27 May – The last maleSumatran rhinoceros inMalaysia is reported to have died, leaving only one female in the country.^[208]
• 28 May – A team from theUniversity of Minnesota andUniversity of Massachusetts exceed theSabatier maximum, with a 10,000-fold increase in the rate of chemical reactions, using waves to create an oscillating catalyst.^[209]

• June – Heuglin's gazelle rediscovered inEritrea.^[211]
• 4 June – Astronomers report the discovery of a star, namedASASSN-V J213939.3-702817.4, non-variable earlier, observed to be associated with a very unusual, deep dimming event. The star, in theIndusconstellation, is about 3,630 ly (1,110 pc) away.^{[212][213][214]}
• 5 June – Researchers usingnuclear magnetic resonance show that initially correlated quantum spins can exhibitheat flow from a colder to a hotter system, demonstrating the reversal of the usual thermodynamic heat current due to quantum correlations.^[215][216]
• 6 June – TheInternational Astronomical Union (I.A.U), in celebration of its hundredth anniversary, in a project calledIAU100 NameExoWorlds, is reported to welcome countries of the world, to submit names forastronomical objects, particularlyexoplanets and itshost star, which would later be considered for official adoption by the organization.^{[217][218][219]}
• 10 June
  • Scientists report thatAhuna Mons, a very high dome-shaped mountain on thedwarf planetCeres, may have been formed by a plume of mud ejected from deep within the planet.^[210][220]
  • A study by researchers from theRoyal Botanic Gardens, Kew, identifies nearly 600plants that have disappeared since the Industrial Revolution – more than twice the number of birds, mammals and amphibians combined – with extinctions now occurring 500 times faster than the natural background rate.^[221][222]
• 11 June
  • Astronomers report that theusual Hubble classification, particularly concerningspiral galaxies, may not be supported, and may need updating.^[223]
  • Researchers at the University of Colorado Boulder demonstrate "nanobio-hybrid" organisms capable of using airborne carbon dioxide and nitrogen to produce a variety of eco-friendly plastics and fuels.^[224]
• 12 June
  • The discovery ofcold quasars is announced at the 234th meeting of theAmerican Astronomical Society.^[225]
  • Astronomers report the discovery of twoEarth-mass exoplanets orbitingTeegarden's Star within itshabitable zone.^[226][227]
• 19 June – Researchers atCarnegie Mellon University demonstrate the first noninvasive mind-controlled robotic arm.^[228]
• 20 June – Researchers atLancaster University describe a new electronic memory device that combines the properties of bothDRAM andflash, while recording or deleting data using hundreds of times less energy.^[229]

• 21 June – Scientists release the video appearance, for the second time, and for the very first time in waters of the United States, of agiant squid in itsdeepwater habitat.^{[230][231][232]}
• 22 June – Scientists working with theCuriosity rover on the planetMars report the detection of a significant amount ofmethane, thelargest amount ever detected by the rover – 21parts per billion units by volume (ppbv) (i.e., one ppbv means that if you take a volume of air on Mars, one billionth of the volume of air is methane). Methane is a possible indicator oflife, but may also be producedgeologically.^{[233][234][235]}
• 23 June – Researchers in Greece report for the first time, a single-stepLaser texturing process for the fabrication ofanti-reflective transparent surfaces based onbiomimicry.^[236]
• 24 June – SpaceX successfully launches theFalcon Heavy for the 3rd time with theSTP-2 mission. This is also the first Falcon Heavy mission contracted by theUnited States Government.
• 27 June – NASA'sDragonfly spacecraft is selected to become the fourth mission in theNew Frontiers program. It will launch in 2026, arriving on the surface of Saturn's moonTitan in 2034.^[237][238]
• 28 June
  • Russian astronomers report thediscovery of nineFast Radio Burst (FRB) events (FRB 121029, FRB 131030, FRB 140212, FRB 141216, FRB 151125.1, FRB 151125.2, FRB 160206, FRB 161202, FRB 180321), which include one repeating FRB (FRB 151125, third one ever detected), from the direction of theM 31 (Andromeda Galaxy) andM 33 (Triangulum Galaxy)galaxies during the analysis of archive data (July 2012 to December 2018) from theBSA/LPIlarge phased arrayradio telescope at thePushchino Radio Astronomy Observatory.^{[239][240][241]}
  • Astronomers report the detection of astar, namedHD 139139 (EPIC 249706694), thatdims in brightness in an apparentrandom, and currently unexplainable, way.^{[242][243][244]}
• 29 June – Scientists report that all 16 GB ofWikipedia have been encoded intosynthetic DNA.^[245]

• 1 July
  • Astronomers report thatʻOumuamua, aninterstellar object that passed through theSolar System in October 2017, was an object of a "purely natural origin", and not otherwise.^[246][247]

• • MRI scans were performed on individual atoms.^[250][251]
• 2 July
  • TheEuropean Centre for Medium-Range Weather Forecasts reports that the global average temperature for June 2019 was the highest on record for the month, at 0.1 °C higher than that of the previous warmest June, in 2016.^[252][253]
  • Atotal solar eclipse occurs, with totality visible in theSouth Pacific andSouth America.^{[citation needed]}
  • Astronomers report thatFRB 190523, a non-repeatingFast Radio Burst (FRB), has been discovered and, notably, localized to a few-arcsecond region containing a single massivegalaxy at aredshift of 0.66, nearly 8 billion light-years away from Earth.^[254][255]
• 3 July
  • Scientists from theUniversity of Bristol describe a new way to directstem cells toheart tissue, using a designeradhesiveprotein.^[256]
  • Researchers identify more than a 1 million square kilometres (0.39 million square miles) of lost tropicalrainforest across theAmericas,Africa andSoutheast Asia, with a high potential forrestoration.^{[257][248][249]}
• 7 July – Researchers report receiving the first pictures fromLightSail 2, aCubeSat developed byThe Planetary Society, and launched intoEarth orbit on 25 June 2019 by aFalcon Heavy rocket.^[258]

• 8 July – Astronomers report that a new method to determine theHubble constant, and resolve the discrepancy of earlier methods, has been proposed based on the mergers of pairs ofneutron stars, following the detection of the neutron star merger ofGW170817.^[261][262] Their measurement of the Hubble constant is70.3+5.3
  −5.0 (km/s)/Mpc.^[263]
• 10 July – Anthropologists report the discovery of 210,000 year old remains of aHomo sapiens and 170,000 year old remains of aNeanderthal inApidima Cave in southernGreece, over 150,000 years older than previous H. sapiens finds in Europe.^{[264][265][266]}
• 11 July
  • Astronomers report, for the first time, detection of amoon-formingcircumplanetary disk around a distantplanet, particularlyPDS 70c.^{[267][259][260]}
  • Carnegie Mellon University reports anartificial intelligence program, developed in collaboration with Facebook AI, which is able to defeat leading professionals in six-player no-limitTexas hold'em poker.^[268]
• 12 July – Physicists report, for the first time, capturing an image ofquantum entanglement.^[269][270]
• 13 July – The Russian/GermanSpektr-RG observatory is successfully launched into space, on a seven-year mission to studyX-ray sources.^[271]
• 15 July
  • Astronomers report thatnon-repeatingFast Radio Bursts (FRB)s may not be one-off events, but actually FRB repeaters with repeat events that have gone undetected and, further, that FRBs may be formed by events that have not yet been seen or considered.^[272][273]
  • A paper is released in the journalNature Astronomy in which researchers fromHarvard University, theUniversity of Edinburgh andNASA'sJet Propulsion Laboratory (JPL) detail how silicaaerogel could be used to block radiation, obtain water and permit photosynthesis to occur to make Mars more hospitable for human survival.^{[274][275][276][277]}

• 16 July – Astronomers report the determination, based on a new method (Red Giant Stars method), of theHubble Constant as 69.8 km s−1 Mpc−1, a value in the middle of two earlier values determined by two other methods: 67.4 (CMB Radiation method) and 74.0 (Cepheids method).^[279][280]
• 17 July – Astronomers rule out the chances of ~30 m (98 ft) asteroid2006 QV89's hitting Earth in September 2019 by eliminating the possibility of its passing through an area where it would have to be if it were on an impacting orbit. Prior to this, the asteroid had been given a one-in-7,000 chance of hitting Earth.^[281]
• 22 July
  • TheIndian Space Research Organisation (ISRO) launchesChandrayaan-2, its secondlunar exploration mission, which includes anorbiter,lander androver.^[278]
  • Biochemists and geochemist fromEarth-Life Science Institute (ELSI), Tokyo and theNational University of Malaysia, Bangi report the discovery of simpleorganic molecules(hydroxy acids) that can assemble themselves into possibleprotocells underconditions similar to those of theearly Earth.^[282][283]
• 25 July – Astronomers report that2019 OK, a previously undetected asteroid up to 130 metres (430 feet) across, passed within 72,000 kilometres (45,000 miles) of Earth on 25 July 2019 at 01:22 GMT.^[284]
• 30 July – Astronomers report evidence to support the hypothesis of anancient ocean on the planetMars that may have been formed by a possiblemega-tsunami source resulting from ameteorite impact creatingLomonosov crater.^[285][286]
• 31 July
  • Astronomers report thatGJ 357 d, a "Super-Earth" discovered by NASA'sTransiting Exoplanet Survey Satellite (TESS), lies within the habitable zone of its parent star, 31 light years from Earth.^[287][288]
  • Astronomers report finding an A-type main-sequence star,S5-HVS1, traveling 1,755 km/s (3,930,000 mph), faster that any other star detected so far. The star is in theGrus (or Crane)constellation in the southern sky, and about 29,000 light-years from Earth, and may have been ejected out of theMilky Waygalaxy after interacting withSagittarius A*, thesupermassive black hole at the center of the galaxy.^{[289][290][291][292][293]}

• 1 August
  • Astronomers publish the most detailed ever measurements of the "warping" effect on theMilky Way's 3D structure, based on the distribution of more than 2,400Cepheids, using theOptical Gravitational Lensing Experiment (OGLE).^{[294][295][296]}
  • Researchers atCarnegie Mellon University publish details of a new technique for3D bioprinting oftissue scaffolds made fromcollagen, the majorstructural protein in thehuman body.^[297]
  • Danish polar research institution, Polar Portal, reports a spike inGreenland ice loss, with 11 billion tons melted in one day and 197 Gigatonnes during the month of July.^[298]

• 5 August
  • Scientists report that a capsule containingtardigrades incryptobiotic state (as well as a laser-etched copy ofWikipedia in glass) may have survived the April 2019 crash landing on theMoon ofBeresheet, a failed Israelilunar lander.^[299][300]
  • Engineers at the University of Buffalo reveal a new device able to cool parts of buildings by up to 11 °C (20 °F), without consuming electricity. The system uses an inexpensive polymer/aluminum film at the bottom of a solar "shelter", which absorbs heat from the air inside the box and transmits that energy back into outer space.^[301]
• 6 August – Scientists at the University of Leeds create a new form ofgold just two atoms thick, measured at 0.47 nanometres. In addition to being the thinnest unsupported gold ever produced, it functions 10 times more efficiently as a catalytic substrate than larger gold nanoparticles.^{[302][303][304]}
• 7 August – Biologists report the discovery of the fossil remains of a first-of-its-kind extinct giantparrot namedThe Hercules parrot (orHeracles inexpectatus) inNew Zealand. The parrot is thought to have stood up to 1 m (3 ft 3 in) tall and weighed approximately 7 kg (15 lb).^[305][306]
• 8 August
  • Astronomers report that theMagnetospheric Multiscale Mission (MMS) made the first high-resolution measurements of aninterplanetary shock wave from thesun.^[307]
  • Researchers atHarvard report the creation of "cyborgorganoids", which consist of 3D organoids grown from stem cells, with embedded sensors to measure activity in the developmental process.^[308]
• 9 August
  • Astronomers report the detection of eight very unusualrepeatingFast Radio Burst (FRB) signals inouter space.^[309][310]
  • Scientists report the isolation and culture ofLokiarchaea, amicroorganism that may help explain the emergence of complexeukarotic (nucleated) cells from simplerbacteria-like cells.^[311]

• 11 August
  • Researchers report thatWindows 10 users may be at risk for "critical" system compromise due to design flaws of hardwaredevice drivers from multiple providers.^[312]
  • Astronomers using theKeck Observatory report a sudden brightening ofSagittarius A*, which became 75 times brighter than usual, suggesting that the supermassive black hole may have encountered another object.^[313]
• 13 August – Computer experts report that theBlueKeepsecurity vulnerability that potentially affects older unpatchedMicrosoft Windows versions via the program'sRemote Desktop Protocol, allowing for the possibility ofremote code execution, may now include related flaws, collectively namedDejaBlue, affectingnewer Windows versions (i.e.,Windows 7 and all recent versions) as well.^[314]
• 14 August
  • Computer experts report aMicrosoftsecurity vulnerability,CVE-2019-1162, based onlegacy code involvingMicrosoft CTF and ctfmon (ctfmon.exe), that affects allWindows versions from the olderWindows XP version to the most recentWindows 10 versions; a patch to correct the flaw is currently available.^[315]
  • Astronomers report the best candidate yet for thecollision, named S190814bv, of ablack hole with aneutron star, based on the detection ofgravitational wave signals.^[316]
  • The most accurate study ofexoplanets to date, published byPenn State, estimates that one in six Sun-like stars contain planets of similar size and orbital period to Earth.^[317]
• 15 August
  • Chemists report the formation, for the first time, of an 18-atomcyclocarbon of purecarbon; such chemical structures may be useful as molecular-sized electronic components.^[318]
  • TheNational Oceanic and Atmospheric Administration (NOAA) reports that July 2019 was the hottest month on record globally, at 0.95 °C (1.71 °F) above the 20th century average.^{[319][320][321]}

• 19 August
  • NASA reports that theEuropa Clipper mission toEuropa, a moon of the planetJupiter, has been confirmed.^[322]
  • The first computer chip to exceed one trilliontransistors, known as the Wafer Scale Engine, is announced by Cerebras Systems in collaboration withTaiwan Semiconductor Manufacturing Company (TSMC).^[323]
• 22 August – Research by Norwegian scientists adds to a growing body of evidence that too muchsitting is related to a higher risk of early death, and that even a small amount of regular activity canlengthen lifespan.^[324]
• 23 August
  • Austrian and Chinese scientists report the first teleportation of three-dimensional quantum states, or "qutrits", which are more complex than two-dimensionalqubits.^[325]
  • NASA reports that theDeep Space Atomic Clock (DSAC), to be used for preciseradio navigation indeep space, has been activated.^[326]
• 26 August – Astronomers report that newly discovered long-term pattern of absorbance andalbedo changes in theatmosphere of the planet Venus are caused by "unknown absorbers", which may bemicroorganisms high up in theatmosphere of theplanet.^[327][328]
• 28 August
  • Scientists report the discovery of a nearly intact skull, for the first time, and dated at 3.8 million years ago, ofAustralopithecus anamensis inEthiopia.^[329]
  • Astronomers report the discovery, based on deep, irregularly shaped transits, of a seconddisrupted planetary object being ripped apart by its host star; in this instance, the host star is awhite dwarf namedZTF J0139+5245; the first such similar host star discovered wasWD 1145+017 in 2015.^[330]
  • Scientists report the discovery of a new distinctivelight wave, named aDyakonov–Voigt wave, that results from a particular manipulation of crystals, that was first suggested in equations developed by physicistJames Clerk Maxwell in the middle 1800s.^[331][332]
• 29 August – Astronomers report that the exoplanet in theWASP-49 system might have avolcanically activeexomoon.^[333]
• 30 August
  • In a study published in the journalPLOS Pathogens, researchers at Spain'sCarlos III Health Institute note the discovery of the genetic mutuationTNPO3, known for causing muscular dystrophy, may also give protection against HIV.^{[334][335][336]}
  • Scientists in China report a way of regrowing the complex structure oftooth enamel, using calcium phosphate ion clusters as a precursor layer.^[337][338]

• 2 September – Insilico Medicine reports the creation, via artificial intelligence, of six novel inhibitors of theDDR1 gene, a kinase target implicated infibrosis and other diseases. The system, known as Generative Tensorial Reinforcement Learning (GENTRL), designed the new compounds in 21 days, with a lead candidate tested and showing positive results in mice.^{[340][341][342]}
• 5 September – Astronomers report that the observed dimmings ofTabby's Star may have been produced by fragments resulting from thedisruption of an orphanedexomoon.^[343][344]
• 6 September
  • Computer experts announce that an exploit of thewormableBlueKeepsecurity vulnerability, affecting all unpatched Windows NT-based versions ofMicrosoft Windows fromWindows 2000 throughWindows Server 2008 R2 andWindows 7, has now been released into the public realm.^[339]
  • Mathematicians report, after a 65-year search (since 1954), thesolution to the last integer left below 100 (i.e., "42") expressed as thesum of three cubes.^[345]
  • A team of physicists report that the supposed discrepancy in theproton radius betweenelectronic andmuonic hydrogen does not exist, settling theproton radius puzzle.^[346]
• 7 September – TheIndian Space Research Organisation (ISRO) loses contact withChandrayaan-2, its second lunar probe, just moments before it was expected to land on the Moon's surface.^[347]
• 10 September – Scientists report the computerized determination, based on 260CT scans, of a virtualskull shape of thelast common human ancestor tomodern humans, and suggests that the human ancestor arose through a merging of populations inEast andSouth Africa, between 260,000 and 350,000 years ago.^[348][349]
• 11 September
  • Astronomers report the detection of water vapour in the atmosphere of thecircumstellar habitable zone exoplanetK2-18b, which may be between 0 and 40 °C.^[350][351]
  • Researchers at theSwiss Federal Institute of Technology demonstrate the first artificial hand for amputees that merges user and robotic control, a concept in neuroprosthetics known asshared control.^[352]
  • Astronomers at theMinor Planet Center confirm the detection of cometC/2019 Q4 (Borisov),^[353][354] likely a secondinterstellar object, following the earlier discovery ofʻOumuamua.^[355]
  • Google reports the creation of a deep learning system, trained on 50,000 different diagnoses, able to detect 26skin conditions as accurately as dermatologists.^[356][357]

• 16 September
  • Biochemists report that "RNA-DNA chimeras" (complex mixtures ofRNA molecules andDNA molecules) may be a more effective way of producingprecursor life biochemicals, than the more linear approaches (with pure RNA and pure DNA molecules) used earlier.^[358][359]
  • UsingCRISPR, researchers in the U.S. engineer aplasmid to remove anantibiotic resistance gene from theEnterococcus faecalis bacterium.^[360][361]
  • Astronomers using theGreen Bank Telescope identify a rapidly rotating millisecondpulsar, calledJ0740+6620, as the most massiveneutron star ever observed, with 2.17 solar masses in a sphere only 30 kilometers across.^[362]
  • Scientists at theMayo Clinic report the first successful use ofsenolytics, a new class of drug with potential anti-aging benefits, to removesenescent cells from human patients with a kidney disease.^[363][364]
  • In a study published inPNAS, researchers at MIT detail a new emission free method of cement production, a major contributor to climate change.^[365][366]
• 17 September – A small clinical trial, announced by U.S. company NeuroEM Therapeutics, shows reversal of cognitive impairment inAlzheimer's disease patients after just two months of treatment using a wearable head device.Electromagnetic waves emitted by the device appear to penetrate the brain to break up amyloid-beta and tau deposits.^[367]
• 19 September – Researchers report on thefacial appearance ofDenisovans, anextinct group ofarchaic humans in thegenusHomo, based ongenetic information.^{[368][369][370]}
• 20 September – Scientists report that theInSightlander on the planetMars uncovered unexplainedmagnetic pulses, andmagnetic oscillations may be consistent with a planet-wide reservoir of liquid water deep underground.^[371]

• 25 September
  • TheIntergovernmental Panel on Climate Change (IPCC) releases itsSpecial Report on the Ocean and Cryosphere in a Changing Climate. This includes a revised projection forsea level rise, upwards by 10 cm to 1.1 metres by 2100.^{[373][374][375]}
  • Canadian company Deep Genomics announces that itsAI-based drug discovery platform has identified a target and drug candidate forWilson's disease. The candidate, DG12P1, is designed to correct theexon-skipping effect of Met645Arg, a genetic mutation affecting the ATP7B copper-binding protein.^[376]
  • Engineers atDuke University report the use ofmachine learning to rapidly design dielectric (non-metal)metamaterials that absorb and emit specific frequencies of terahertz radiation.^[377]
  • TheAmery Ice Shelf inAntarctica produces its largest iceberg in more than 50 years, with a chunk called D28 being calved off that is 1,636 km² in area and weighs an estimated 315 billion tonnes.^[372]
• 27 September – Astronomers report, for the first time, the release ofcyanide gas anddust from aninterstellar object, particularly from theinterstellar comet2I/Borisov.^[378]
• 30 September – By combining doses oflithium,trametinib andrapamycin into a single treatment, researchers extend the lifespan offruit flies (Drosophila) by 48%.^[379]

• 1 October
  • Scientists at theDeep Carbon Observatory quantify the amount ofcarbon held by the Earth, finding that 1.85∗10¹⁸ tonnes is present, the vast majority below ground.^[381][382]
  • Scientists at theUniversity of California, San Diego describe how a protein namedDsup (Damage suppression protein) binds tochromatin, which protects the cells oftardigrades and may explain the animals' tremendous resilience.^[383]
  • Physicists report a way of determining the state ofSchrödinger's catbefore observing it.^[384][385]
• 2 October – Scientists reveal the photo carrier dynamics inheterojunctionphototransistors and show how molecular packing can impact on photoresponse. The study could lead to new schemes to engineer efficient photo carrier transport in general.^[386]
• 4 October – Scientists use a new parallelised technique, known asfemtosecond projection TPL (FP-TPL), to 3D print nanoscale structures up to 1,000 times faster than conventionaltwo-photon lithography (TPL).^[387][388]
• 7 October
  • NASA reports evidence, uncovered by theCuriosity rover onMount Sharp, of a 150 km (93 mi) wide ancient basin inGale crater that once may have contained asalty lake.^[389][390]
  • 20 newmoons of Saturn are discovered byScott S. Sheppard and his team at theCarnegie Institution for Science, taking the planet's total known number to 82, surpassingJupiter.^[391][392]
  • Researchers genetically engineerEscherichia coli that can manufacture large amounts ofpsilocybin, which is in clinical trials for treating depression and other brain diseases.^[393]
• 8 October – Researchers atDuke University Health System identify a mechanism forcartilage repair in humans, which could allow joints and possibly entire limbs to regenerate.^[380]
• 15 October –OpenAI demonstrates a pair of neural networks trained to solve aRubik's Cube with a highly dexterous, human-like robotic hand.^[394][395]
• 16 October – Researchers atHarvard Medical School identify a link between neural activity and human longevity. Neural excitation is linked to shorter life, while suppression of overactivity appears to extend lifespan.^[396]
• 17 October –Northwestern University researchers unveil a new3D printer known as HARP (high-area rapid printing), which can produce an object the size of an adult human within two hours, without sacrificing quality or resolution.^[397]

• 18 October
  • Researchers at theUniversity of California, Santa Cruz, describe the use of nanoscale optical probes to monitor neural activity, with potential to greatly increase the scale and bandwidth available compared to microelectrode arrays.^[399][400]
  • A new stable form ofplutonium, which may be a transient phase in radioactive waste repositories, is discovered by scientists using theEuropean Synchrotron in Grenoble, France.^[401]
• 21 October
  • In a study, published in the journalNature, researchers at theBroad Institute describe a new method of genetic engineering superior to previous methods likeCRISPR they call "prime editing".^{[402][403][404]}
  • Researchers report that theCretaceous Chicxulub asteroid impact that resulted in theextinction of non-aviandinosaurs 66 million years ago, also rapidlyacidified the oceans producingecological collapse and long-lasting effects on the climate, and was a key reason for end-Cretaceousmass extinction.^[405][406]
• 22 October – Scientists publish a paper claiming support for their controversial and disputedYounger Dryas impact hypothesis that theextinction of ice-age animals may have been caused by a disintegratingasteroid orcometimpact and/orairburst about 12,800 years ago.^[407][408]
• 23 October –Google announces that its 53-qubit'Sycamore' processor has achievedquantum supremacy, performing a specific task in 200 seconds that would take the world's best supercomputers 10,000 years to complete.^{[398][409][410][411]} However, the claim is disputed by someIBM researchers.^[412]
• 25 October – A newcarbon capture system is described by MIT, which can work on the gas at almost any concentration, usingelectrodes combined withcarbon nanotubes.^[413]

• 28 October
  • A study published inNature identifiesBotswana as the birthplace ofanatomically modern humans, based ongenetic studies, around 200,000 BCE.^{[414][415][416][417]}
  • Astronomers observe the large asteroidHygiea in higher resolution than ever before, revealing it to be spherical and a likelydwarf planet candidate; possibly the smallest in theSolar System.^[418][419]
  • Researchers report that the interstellar comet2I/Borisov is outgassing water, and in a manner similar to the outgassing of water in a typical comet in the Solar System.^[420][421]
  • Scientists report that terrestriallifeforms, including extreme forms ofarchaeamicroorganisms, were not found to exist in very hot, acidic and salty conditions present in some areas of Earth, including in theDanakil Depression ofEthiopia.^[422][423]
• 29 October – A study inNature concludes thatrising sea levels will threaten 300 million people by 2050, more than triple previous estimates. The upward revision is based on the use of amultilayer perceptron, a class ofartificial neural network, which analysed topographical maps in greater detail than before and provided more accurate land elevations.^{[424][425][426]}
• 30 October – A large-scale study by researchers inGermany finds thatinsect populations declined by one-third between 2008 and 2017.^{[427][428][429]}
• 31 October – Researchers at theKTH Royal Institute of Technology, Sweden, develop a new film that is applied to solar cells, which combines nanocrystals and microlenses to captureinfrared light. This can increase the solar energy conversion efficiency by 10 percent or more.^[430]

• 1 November – Researchers atRensselaer Polytechnic Institute demonstrate a way to 3D printliving skin, complete with blood vessels, which could be used for more natural and accurategrafts.^[433]
• 4 November – Scientists confirm that, on 5 November 2018, theVoyager 2 probe had officially reached theinterstellar medium (ISM), a region ofouter space beyond the influence of theSolar System, and has now joined theVoyager 1 probe which had reached the ISM earlier in 2012.^[431][432]
• 5 November – 11,000 scientists from around the world publish a study in the journalBioScience, warning "clearly and unequivocally that planet Earth is facing aclimate emergency."^{[434][435][436]}
• 6 November – Scientists at theUniversity of Rochester demonstrate a new technique for creatingsuperhydrophobic metals that float on water, usingfemtosecond laser bursts to "etch" the surfaces and trap air.^[437]
• 8 November
  • Microsoft confirms a potentiallywormableBlueKeepsecurity vulnerability attack, and urges users to immediately patch theirMicrosoft Windowscomputer systems.^[438]
  • Computer experts atKaspersky Lab report the detection of a very advanced and insidiousbackdoormalwareAPT namedTitanium, that was developed byPLATINUM, acybercrime collective.^[439][440]
• 12 November –486958 Arrokoth, atrans-Neptunian object previously nicknamed "Ultima Thule" and visited by theNew Horizons spacecraft, receives its official name during a ceremony at the NASA Headquarters.^[441]

• 13 November
  • Jim Peebles, awarded the 2019Nobel Prize in Physics for his theoretical discoveries inphysical cosmology.^[443] notes, in his award presentation, that he does not support theBig Bang Theory, due to the lack of concrete supporting evidence, and states, "It's very unfortunate that one thinks of the beginning whereas in fact, we have no good theory of such a thing as the beginning."^[444]
  • Researchers report thatastronauts experienced seriousblood flow andclot problems while on board theInternational Space Station, based on a six-month study of 11 healthy astronauts. The results may influence long-termspaceflight, including a mission to the planetMars, according to the researchers.^[445][446]
  • Scientists in Japan use single-cell RNA analysis to find thatsupercentenarians have an excess of cytotoxic CD4 T-cells, a type of immune cell.^[447]
• 15 November – The discovery and interpretation of 143 newNazca geoglyphs is announced by researchers fromYamagata University.^[442]
• 18 November
  • Internal-wave cooling of threatenedcoral reefs quantified across the Pacific Ocean by an international collaboration led byThe Hong Kong University of Science and Technology is published inNature Geoscience^[448]
  • Titan, the largest moon of Saturn, is fully mapped for the first time, using data from NASA'sCassini mission.^[449]
  • Scientists report detecting, for the first time,sugar molecules, includingribose, inmeteorites, suggesting that chemical processes onasteroids can produce some fundamentally essential bio-ingredients important tolife, and supporting the notion of anRNA world prior to a DNA-basedorigin of life on Earth, and possibly, as well, the notion ofpanspermia.^{[450][451][452]}
  • Researchers at theUniversity of Notre Dame develop a new method for lifelong learning inartificial neural networks, which entails the use of a ferroelectric ternarycontent-addressable memory component. Their study, featured inNature Electronics, aims to replicate thehuman brain's ability to learn from only a few examples, adapting to new tasks based on past experiences.^[453]
• 20 November
  • Astronomers report a notablegamma ray burst explosion, namedGRB 190114C, initially detected in January 2019, that, so far, has been determined to have had the highest energy,1 Tera electron volts (Tev), ever observed for such a cosmic event.^[454][455]
  • A study shows that theconsensus among climate change scientists has grown to 100%, based on a review of 11,602peer-reviewed articles published in the first seven months of 2019.^[456]

• 23 November – The last knownSumatran rhinoceros inMalaysia passes on.^[457]
• 25 November
  • IPv4 address exhaustion: TheRIPE NCC, which is the official regionalInternet registry (RIR) for Europe, officially announces that it has run out ofIPv4 Addresses.^[458]
  • TheWorld Meteorological Organization reports that levels of heat-trappinggreenhouse gases in theatmosphere reached another new record high of 407.8 parts per million in 2018,^[459] with "no sign of a slowdown, let alone a decline."^[460][461]
• 26 November
  • Astronomers fromYale University report that the recently detectedinterstellar comet2I/Borisov (includingcoma and tail), is "14 times the size of Earth", presented animageArchived 18 July 2023 at theWayback Machine comparing the comet size with the size of planet Earth [...] and stated, "It's humbling to realize how small Earth is next to this visitor from another solar system."^[462]
  • Researchers report, based on an international study of 27 countries, thatcaring for families is the main motivator for people worldwide.^[463][464]
• 27 November
  • Researchers report the discovery ofCaveasphaera. amulticellular organism found in 609-million-year-old rocks, that is not easily defined as ananimal or non-animal, which may be related to one of the earliest instances ofanimal evolution.^[465][466]
  • Scientists at theUniversity of Exeter report that more than half of nineclimate change tipping points identified a decade ago are now "active".^[467]
  • Chinese astronomers report the discovery ofLB-1, the name of a galacticB-type star,^[468] as well as the name of a very closely associated over-massivestellar-mass black hole,^[469] at least 7,000 light-years (2,100 pc) from Earth.^[469] The black hole is, at nearly 70 solar masses, over twice the mass as the maximum predicted by most current theories ofstellar evolution.^{[468][469][470]}

• 2 December
  • Researchers at theU.S. Department of Energy demonstrateX-ray Laser-Enhanced Attosecond Pulse generation (XLEAP), a new method for observing the movements ofelectrons, using lasers just 280attoseconds long.^[473]
  • Researchers fromTel Aviv University describe how a molecule known as PJ34 triggers the self-destruction ofpancreatic cancer cells, which were reduced by up to 90% in mouse models.^[471][472]
• 3 December – Researchers from theUniversity of Bath report the creation of artificialneurons that reproduce the electrical properties of biological neurons onto semiconductor chips.^[474][475]
• 4 December – Astronomers publish the first evidence of a giant planet orbiting a white dwarf,WDJ0914+1914, suggesting that planets in theSolar System may survive thedeath of the Sun in thedistant future.^{[476][477][478]}
• 5 December – Researchers at theCalifornia Academy of Sciences report the discovery of 71 newplant andanimalspecies, which includes 17fish, 15geckos, 8flower plants, 6sea slugs, 5arachnids, 4eels, 3ants, 3skinks, 2skates, 2wasps, 2mosses, 2corals and 2lizards.^[479]
• 6 December – New calculations show that hollow spherical bubbles containingpositronium gas are stable in liquid helium and could therefore serve as the source of positroniumBose-Einstein condensates forgamma-ray lasers, which could be used for medical imaging, spacecraft propulsion, and cancer treatment. Work to realize such bubbles is ongoing and near term results might have applications inquantum computing.^[480]
• 7 December –Didier Queloz, winner of the 2019Nobel Prize in Physics, takes issue with those who are not supportive of helping to improveclimate change, stating, "I think this is just irresponsible, because the stars are so far away I think we should not have any serious hope to escape the Earth [...] Also keep in mind that we are a species that has evolved and developed for this planet. We're not built to survive on any other planet than this one [...] We'd better spend our time and energy trying to fix it."^[481]
• 8 December – Astronomers report that the starBetelgeuse has significantly "fainted" in visibility and, possibly as a result, may suggest the star to be in the last stages of itsevolution, and may be expected to explode as asupernova within the next 100,000 years, much sooner than thought previously.^{[482][483][484]}

• 9 December
  • Researchers atEPFL discover that theviscosity of solutions of electrically chargedpolymers dissolved in water is influenced by a quantum effect. This tiny quantum effect influences the way water molecules interact with one another.^[486]
  • Researchers publish a study, "Ultrafast stimulated emission microscopy of single nanocrystals," in which they report on a technique for studyingfemtosecond events in non-fluorescent, nano-scale objects.^[487]
  • Researchers reportquantum states being achieved in materials such assilicon carbide and components such asdiodes used in ordinary electronics.^[488]
  • Scientists in China createpigs withmonkeyDNA; thus creating an animal hybrid withgenetic material from two different species.^[489]
  • Intel reveals a first-of-its-kindcryogenic control chip – code-named "Horse Ridge" – for control of multiple quantum bits (qubits) and scaling of larger quantum computer systems.^[490]
  • Researchers develop aself-cleaning mechanism for solar panels, which can remove particles on its surface more effectively than methods used previously. Due towet-chemically etchednanowires and ahydrophobic coating on the surface, water droplets can remove 98% of dust particles.^[491]
• 10 December
  • Astronomers report studies that question the validity of an essential assumption supporting the existence ofdark energy, suggesting that dark energy may not actually exist. Lead researcher of the new studies, Young-Wook Lee ofYonsei University, said, "QuotingCarl Sagan,extraordinary claims require extraordinary evidence, but I am not sure we have such extraordinary evidence for dark energy. Our result illustrates that dark energy fromSN cosmology, which led to the2011 Nobel Prize in Physics, might be an artifact of a fragile and false assumption."^[492][493]
  • NASA scientists report that substantial amounts of "water ice" may be readily available just below the surface on the planetMars, in some particularly well mapped areas (image).^[485]
  • Ford Motor Company, in a joint research project withMicrosoft, reveals a "quantum-inspired" algorithm able to cut traffic by 73% and shorten commuting times by 8% in a simulation of 5,000 cars.^[494][495]
• 11 December
  • Scientists report the discovery ofcave art in centralIndonesia that is estimated to be at least 43,900 years old, and noted that the finding was "the oldest pictorial record of storytelling and the earliest figurative artwork in the world".^[496]
  • Researchers find evidence that thecarbon dioxide concentration in the oceans rose beforethe asteroid impact that causedthe extinction of non-avian dinosaurs. This was likely caused by long-termvolcanic eruptions from theDeccan Traps andacidified the oceans already before the asteroid impact. Their results might inform preparations for consequences of contemporary human-caused climate change in theEarth system and were made possible by a new method for analyzing the calcium isotope composition of fossilized sea shells.^[497]
• 13 December – The Japanese government approves construction of theHyper-Kamiokande, the largestneutrino detector in history.^[498]
• 16 December – Scientists report that a lamella-likethin-film transistor composed of metal oxidesemiconductors and organicpolymer can be fabricated at low temperatures from solutions and operate under severe stress conditions. The study could provide a low-cost way for a range applications for large-areaflexible electronics.^[499][500]
• 18 December
  • TheCHEOPS space telescope, whose mission is to study the formation ofextrasolar planets and determine their precise radius, likely density and internal structure, is launched.^[501][502]
  • Scientists report thatHomo erectus, a species of extinctarchaic humans, may have survived to nearly 100,000 years ago, much longer than thought previously.^[503][504]
• 19 December – TheAAAS journalScience reports that the "2019 Breakthrough of the Year" is theimage of asupermassive black hole taken by theEvent Horizon Telescope.^[505][506] The best science findings of 2019 are also reported in other listings byBoston University,^[507]Business Insider^[508][509] andThe New York Times.^{[510][511][512][513]}
• 20 December – The US government authorises, for the first time, the use of federal funds to researchgeoengineering.^[514]
• 26 December – Apartial solar eclipse occurs.
• 28 December – NASA reports that astronautChristina Koch has now spent 289 days on theInternational Space Station, more time in space than any other female astronaut, breaking the previous record of retired astronautPeggy Whitson.^[515]
• 30 December – Chinese authorities announce thatHe Jiankui, the scientist who claimed to have created the world'sfirst genetically edited human babies, has been sentenced to three years in prison and fined 3 million yuan (US$430,000) for his genetic research efforts.^{[516][517][518]}

• Queen Elizabeth Prize for Engineering – Bradford Parkinson,James Spilker, Hugo Fruehauf and Richard Schwartz
• Abel Prize – Karen Uhlenbeck
• TheNobel Prize in Medicine is awarded toWilliam G. Kaelin Jr.,Peter J. Ratcliffe andGregg L. Semenza for their work on the regulation ofoxygen at the cellular level.^[519]
• TheNobel Prize in Physics is awarded toJames Peebles,Michel Mayor andDidier Queloz for their discoveries about thecosmos.^[520]
• TheNobel Prize in Chemistry is awarded toJohn B. Goodenough,M. Stanley Whittingham andAkira Yoshino for their work onlithium batteries.^[521]

This section needs to beupdated. The reason given is:This section seems to be missing November and December, and possibly parts of January, September, and October. Needs checking with the subarticles ofDeaths in 2019.. Please help update this article to reflect recent events or newly available information.(October 2019)

• 11 January – Michael Atiyah, British-Lebanese mathematician and Fields medalist (b. 1929)
• 6 February – Manfred Eigen, German chemist and Nobel laureate (b. 1927)
• 14 February – Simon P. Norton, English mathematician, co-discoverer of 'monstrous moonshine' (b. 1952)^[522]
• 18 February – Wallace Smith Broecker, American geophysicist, coined the term "global warming" (b. 1931)^[523]
• 1 March – Zhores Alferov, Soviet-Russian physicist and Nobel laureate (b. 1930)
• 20 March
  • Georg Kreutzberg, German neurobiologist (b. 1934)
  • Noel Hush, Australian chemist (b. 1924)
• 21 March – Roger Moore, American computer scientist (b. 1939)
• 28 March – Koji Nakanishi, Japanese chemist (b. 1925)
• 30 March – John Wilson Moore, American biophysicist (b. 1920)
• 5 April – Sydney Brenner, South African molecular biologist and Nobel laureate (b. 1927)
• 6 April – David J. Thouless, British physicist and Nobel laureate (b. 1934)
• 13 April – Paul Greengard, American neuroscientist and Nobel laureate (b. 1925)
• 15 April – Winston L. Shelton, American inventor (b. 1922)
• 2 May – Li Xintian, Chinese psychologist (b. 1924)
• 3 May – Goro Shimura, Japanese mathematician (b. 1930)
• 6 May – George Zimmerman, American physicist (b. 1935)
• 8 May – Robert McEliece, American mathematician and engineer (b. 1942)
• 9 May – Zhan Wenshan, Chinese physicist (b. 1941)
• 10 May – Geneviève Raugel, French mathematician (b. 1951)
• 13 May – Lo Tung-bin, Taiwanese biochemist (b. 1927)
• 14 May – Michael Rossmann, American physicist and microbiologist (b. 1930)
• 15 May – Charles Kittel, American physicist (b. 1916)
• 18 May – Mario Baudoin, Bolivian biologist (b. 1942)
• 24 May – Murray Gell-Mann, American physicist and Nobel laureate (b. 1929)
• 25 May – Margaret-Ann Armour, Canadian chemist (b. 1939)
• 27 May
  • Laurie Hendren, Canadian computer scientist (b. 1958)
  • Aharon Razin, Israeli biochemist (b. 1935)
• 28 May
  • Li Hengde, Chinese material scientist (b. 1921)
  • Wlodzimierz Ptak, Polish immunologist and microbiologist (b. 1928)
• 1 June
  • Harry Triandis, American psychologist (b. 1926)
  • Fons van de Vijver, Dutch psychologist (b. 1952)
• 2 June – Henry Lynch, American physician (b. 1928)
• 3 June – Tang Dingyuan, Chinese physicist (b. 1920)
• 4 June – Teruko Ishizaka, Japanese immunologist (b. 1926)
• 12 June – Wilbert McKeachie, American psychologist (b. 1921)
• 13 June – Heinrich Reichert, Swiss neurobiologist (b. 1949)
• 14 June
  • George Felton, British computer scientist (b. 1921)
  • James Wyngaarden, American physician (b. 1924)
• 16 June
  • Frederick Andermann, Canadian neurologist (b. 1930)
  • Feng Chuanhan, Chinese osteologist (b. 1914)
  • Francine Shapiro, American psychologist (b. 1948)
• 17 June
  • Kung Hsiang-fu, Chinese molecular biologist (b. 1942)
  • Clemens Roothaan, Dutch physicist and chemist (b. 1918)
• 20 June – Jean-Marie Hullot, French computer scientist (b. 1954)
• 22 June – Robert Levine, American psychologist (b. 1945)
• 23 June – George Rozenkranz, Mexican chemist (b. 1916)
• 29 June – Dieter Enders, German chemist (b. 1946)
• 30 June – Mitchell Feigenbaum, American physicist (b. 1944)
• 2 July – Suzanne Eaton, American biologist (b. 1959)
• 3 July – Arseny Mironov, Russian aeronautical engineer (b. 1917)
• 6 July – Calvin Quate, American engineer (b. 1923)
• 10 July
  • Karen Hitchcock, American biologist (b. 1943)
  • Gerald Weismann, American physician (b. 1930)
• 12 July
  • Fernando J. Corbató, American computer scientist (b. 1926)
  • Claudio Naranjo, Chilean psychiatrist (b. 1932)
  • Richard M. Thorne, American physicist (b. 1942)
• 13 July – Harlan Lane, American psychologist (b. 1936)
• 14 July
  • Rahul Desikan, American neuroscientist (b. 1978)
  • Hoàng Tụy, Vietnamese mathematician (b. 1927)
  • Arvind Varma, American chemical engineer (b. 1947)
• 15 July
  • Rex Richards, British chemist (b. 1922)
  • Thorsteinn Sigfusson, Icelandic physicist (b. 1954)
• 16 July – Judit Bar-Ilan, Israeli computer scientist (b. 1958)
• 18 July – Kurt Julius Isselbacher, American physician (b. 1925)
• 19 July
  • Godfried Toussaint, Canadian computer scientist (b. 1944)
  • Patrick Winston, American computer scientist (b. 1943)
• 20 July – Liane Russell, American geneticist (b. 1923)
• 22 July – Christopher C. Kraft Jr., American aerospace engineer (b. 1924)
• 23 July – Michael Roth, German engineer (b. 1936)
• 27 July – John Robert Schrieffer, American physicist and Nobel laureate (b. 1931)
• 28 July
  • Walter Fiers, Belgian molecular biologist (b. 1931)
  • Li Jisheng, Chinese aerospace engineer (b. 1943)
• 1 August
  • Charles Fadley, American physicist (b. 1941)
  • Zha Quanxing, Chinese electrochemist (b. 1925)
  • Anders P. Ravin, Danish computer scientist (b. 1947)
• 2 August – Carl Bell, American psychiatrist (b. 1947)
• 3 August
  • Steven Gubser, American physicist (b. 1972)
  • Nikolai Kardashev, Russian astrophysicist, author ofKardashev scale (b. 1932)
• 4 August – Ann Nelson, American particle physicist (b. 1958)
• 6 August
  • Zhuo Renxi, Chinese chemist (b. 1931)
  • George F. Simmons, American mathematician (b. 1925)
• 7 August
  • Donald F. Klein, American psychiatrist (b. 1928)
  • Kary Mullis, American biochemist and Nobel laureate (b. 1944)
• 8 August – Stanislaw Konturek, Polish physiologist (b. 1931)
• 10 August – Radoslav Katičić, Croatian linguist (b. 1930)
• 11 August
  • Michael E. Krauss, American linguist (b. 1934)
  • Geoff Malcolm, New Zealand physical chemist (b. 1930)
• 12 August – Danny Cohen, Israeli computer scientist (b. 1937)
• 15 August – Qin Hanzhang, Chinese food scientist (b.1908)
• 20 August – Li Houwen, Chinese surgeon (b. 1927)
• 23 August – Walter Thiel, German chemist (b. 1949)
• 26 August – Chen Jiayong, Chinese metallurgist and chemical engineer (b. 1922)
• 27 August – Zhang Zong, Chinese crystallographer (b. 1929)
• 31 August
  • Wang Buxuan, Chinese physicist (b. 1922)
  • Immanuel Wallerstein, American sociologist (b. 1930)
• 8 September – Chris Dobson, British chemist (b. 1949)
• 11 October – Alexei Leonov, Soviet cosmonaut (Voskhod 2), first person towalk in space. (b. 1934)
• 1 November – Gilles Fontaine, Canadian astrophysicist (b. 1948)
• 2 November – Irwin Fridovich, American biochemist (b. 1929)
• 6 November – Michael Hanack, German chemist (b. 1931)
• 7 November – Margarita Salas, Spanish biochemist and geneticist (b. 1938)
• 18 November – Ching-Liang Lin, Taiwanese physicist (b. 1931)
• 20 November – Mary L. Good, American chemist and politician
• 26 November – Cyrus Chothia, English biochemist (b. 1942)
• 16 December – Hans Kornberg, British-American biochemist (b. 1928)

• 2019 in spaceflight
• List of emerging technologies
• List of years in science