 | |
| Discovery[1][2] | |
|---|---|
| Discovered by | EURONEAR |
| Discovery site | Roque de los Muchachos Observatory |
| Discovery date | 27 February 2023 |
| Designations | |
| 2023 DZ2 | |
| Orbital characteristics[1] | |
| Epoch 25 February 2023 (JD 2460000.5) | |
| Uncertainty parameter 1 | |
| Observation arc | 72 days (includes highly precise radar observations)[1] |
| Earliestprecovery date | 14 January 2023 |
| Aphelion | 3.317±0.0002 AU |
| Perihelion | 0.99388 AU |
| 2.155±0.0001 AU | |
| Eccentricity | 0.5389±0.00003 |
| 3.165±0.0003yr (1,156±0.1 days) | |
| 348.67°±0.001° | |
| 0° 18m 38.16s / day | |
| Inclination | 0.08143° |
| 187.91°±0.0005° | |
| 2023-Apr-04[3] | |
| 5.96°±0.0005° | |
| Earth MOID | 0.000048 AU (7.2 thousand km; 0.019 LD) |
| Physical characteristics | |
| Dimensions | |
| 0.105 hours (6.3 min)[6] | |
| 10.1 (at closest approach 2023)[7] | |
| 24.2±0.4 mag[1] | |
2023 DZ2 is anasteroid roughly 70 meters in diameter, classified as anear-Earth object of theApollo group, and originally aVirtual Impactor (VI). It was first observed on 27 February 2023, when it was 0.11 AU (16 million km) from Earth, with theIsaac Newton Telescope byOvidiu Vaduvescu, Freya Barwell, and Kiran Jhass (ING andUniversity of Sheffield student support astronomers) within theEURONEAR project.[2] It passed 174,644 ± 0.9 km (108,518.75 ± 0.56 mi) ofEarth on March 25, 2023.[1] This is a little less than half the distance to theMoon. This was the largest asteroid to approach this close since2019 OK.[6] On March 21, 2023 with a 66-day observation arc, it was removed from theSentry Risk Table.[8] Due to the highly preciseradar observations on 25 March 2023 we know that the 2004 Earth approach was closer than the 2023 approach.[1]
| Date & time | Nominal distance | uncertainty region (3-sigma) |
|---|---|---|
| 2004-Apr-18 23:57 ± 22 minutes | 129737 km[1] | ± 3000 km[9] |
| 2023-Mar-25 19:49[10][a] | 174644 km[1] | ± 0.9 km[11] |
| 2026-Apr-04 02:01 ± 2 minutes | 1012259 km[1] | ± 120 km[12] |
The 2023 approach was visible toamateur astronomers with modest telescopes and telescopes equipped with animage sensor. From 20–24 March 2023 it was visible in the constellation ofCancer.[7] At about 17:20 UT on the 25th the asteroid brightened to aboutapparent magnitude 10.1[7][b] while overSoutheast Asia, and might have been visible to advanced observers using 10×50binoculars.[c] But for many locations the asteroid did not get brighter than magnitude 12 before setting and was out of the reach of binoculars.
The discovery was carried out within the (Data-parallel detection of Solar System objects and space debris)ParaSOL project that is sponsored byUEFISCDI inRomania and led by Marcel Popescu. The new NEA was identified by Costin Boldea and by the STU ParaSOL software pipeline developed by the amateur astronomer Malin Stanescu. Other members of the EURONEAR collaboration who participated in the data analysis were Marian Predatu, and the amateur astronomers Lucian Curelaru and Daniel Bertesteanu.
2023 DZ2 is approximately 40–90 meters (130–300 feet) in diameter.[4] With an estimatedrotation period of about 6 minutes and alightcurve amplitude of 0.57 magnitudes, the object is suspected of being elongated in shape.[6][13]
The visiblereflectance spectrum of2023 DZ2 is consistent with that of anX-type asteroid.[13] Being a fast rotator and part of the X-complex, it is highly unlikely to have a carbonaceous-like composition linked to a darkalbedo so the size could be in the range 33 to 55 m.[13]
Before the Earth approach, it follows a rather eccentric (0.54), low-inclination (0.08°) orbit of 3.16 years duration, ranging between 0.99 and 3.32AU from theSun.[1] It passed Earth on 25 March 2023[1] which reduces theorbital period to 1,098.4 days (3.007 yr).[14] It came toperihelion (closest approach to the Sun) on 4 April 2023.[3] Earth is in no short-term danger of having a collision with2023 DZ2 thanks to a nearsecular apsidal resonance with Jupiter.[13]
On 18 March 2023 when the asteroid had an observation arc of 63 days, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1-in-430 chance that the asteroid couldimpact Earth on 27 March 2026.[15] Three days later with a 66-day observation arc it was removed from theSentry Risk Table.[8] It is now known that thenominal approach (line of variation) has the asteroid 0.032 AU (4.8 million km)± 900 km from Earth at the time of the potential impact on 27 March 2026.[16] The asteroid will safely approach Earth on 4 April 2026, a week after the potential impact scenario.[1] It was estimated that an impact would produce an upper atmosphere air burst equivalent to 4.5Mt TNT (19 PJ),[5] roughly equal to 214 of theFat Man warhead dropped on Nagasaki, or a little over a third of theTunguska event.
| External videos | |
|---|---|
 2023 DZ2 flyby through a remote telescope of Abbey Ridge Observatory (Canada). | |
| 2023 DZ2 flyby through a Unistellar 112mm telescope under the light pollution of Sacramento, CA. |
| Solution | Observation arc (in days) | JPL Horizons nominal geocentric distance (AU) | uncertainty region (3-sigma) | Impact probability | Torino scale | Palermo scale (max) |
|---|---|---|---|---|---|---|
| JPL #1(2023-Mar-16) | 2 (31 obs) | 0.625 AU (93.5 million km) | ± 700 million km | 1:7700[17] | 0 | –2.19 |
| JPL #3(2023-Mar-17) | 18 (56 obs) | 0.067 AU (10.0 million km) | ± 38 million km | 1:590[18] | 1 | –1.19 |
| JPL #4(2023-Mar-18) | 63 (94 obs) | 0.036 AU (5.4 million km) | ± 9 million km | 1:430[15] | 1 | –1.17 |
| JPL #5(2023-Mar-19) | 64 (122 obs) | 0.033 AU (4.9 million km) | ± 4 million km | 1:71000[19][d] | 0 | –3.40 |
| JPL #6(2023-Mar-20) | 65 (142 obs) | 0.033 AU (4.9 million km) | ± 3 million km | 1:38000000[5] | 0 | –6.14 |
| JPL #7(2023-Mar-21) | 66 (182 obs) | 0.030 AU (4.5 million km) | ± 1 million km | none[8] | N/A | N/A |
| JPL #8(2023-Mar-22) | 67 (246 obs) | 0.030 AU (4.5 million km) | ± 1 million km | none | N/A | N/A |
With anobservation arc of 63 days it peaked at aPalermo scale rating of –1.17[15] with the odds of impact then being about 15 times less than the background hazard level.
The early May 2029 approach is not an impact threat as the orbits only intersect in late March.[17]
