.png) Comet 238P/Read by theJames Webb Space Telescope on September 8, 2022 | |||||||||
| Discovery | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Discovered by | Michael T. Read (Spacewatch) | ||||||||
| Discovery date | 24 October 2005 | ||||||||
| Designations | |||||||||
| Main-belt comet[1][2] Encke-type comet[3] | |||||||||
| Orbital characteristics[3] | |||||||||
| Epoch 7 January 2006 | |||||||||
| Uncertainty parameter 1 | |||||||||
| Aphelion | 3.9645AU (Q) | ||||||||
| Perihelion | 2.3647AU (q) | ||||||||
| 3.1646AU (a) | |||||||||
| Eccentricity | 0.25277 | ||||||||
| 5.63yr | |||||||||
| 28.566° (M) | |||||||||
| Inclination | 1.2662° | ||||||||
| 51.647° | |||||||||
| 2028-Jan-24[4] 2022-Jun-05 (previous)[5] | |||||||||
| 325.76° | |||||||||
| TJupiter | 3.153 | ||||||||
| Physical characteristics | |||||||||
| 0.6 km(approx.)[6] | |||||||||
Meandensity | 1.0 g/cm3(assumed)[6] | ||||||||
| Albedo | 0.04(assumed)[6] | ||||||||
| |||||||||
| 19.62 to 23.41 | |||||||||
| 20.1±0.4R[6] | |||||||||
238P/Read (P/2005 U1) is amain-belt comet[1][2] discovered on 24 October 2005 by astronomerMichael T. Read using theSpacewatch 36-inch telescope onKitt Peak National Observatory. It has an orbit within theasteroid belt and has displayed thecoma of a traditionalcomet. It fits the definition of anEncke-type comet with (TJupiter > 3;a < aJupiter).[3]
Before it was discovered238P came toperihelion on 2005 July 27.[3] When it was discovered on 2005 October 24, it showed vigorous cometary activity until 2005 December 27.[6]Outgassing likely began at least 2 months before discovery.[6] The activity of238P is much stronger than133P/Elst-Pizarro and176P/LINEAR.[6] This may indicate that the impact assumed to have triggered238P's activity occurred very recently.[6]
Observations of238P when it was inactive in 2007 suggests that it has a smallnucleus only about 0.6 km in diameter.[6]
It came to perihelion on 2011 March 10,[6] 2016 October 22.[7][5] and 2022 June 5.[5] It will next come to perihelion on 2028 January 24.[4]
238P/Read was the target of a mission proposal in NASA'sDiscovery Program in the 2010s calledProteus, however it was not selected for further development.[8] Discovery program's founding mission was to an asteroid, but it went to a Near-Earth asteroid.[9] A mission to a main-belt asteroid was proposed in the 1990s(also seeDeep Impact (spacecraft)).[10]
The comet was observed byJames Webb Space Telescope during the 2022 perihelion and it was found spectrographicaly that its coma was composed by water vapor, due to water sublimation, and lacked significant CO2 coma.[11]
| Numbered comets | ||
|---|---|---|
| Previous 237P/LINEAR | 238P/Read | Next 239P/LINEAR |
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