|Discovery date||24 October 2005|
Main-belt comet |
Encke-type comet 
|Epoch 7 January 2006|
|Uncertainty parameter 1|
|Aphelion||3.9645 AU (Q)|
|Perihelion||2.3647 AU (q)|
|3.1646 AU (a)|
|0.6 km (approx.)|
|19.62 to 23.41|
238P/Read (P/2005 U1) is a main-belt comet discovered on 24 October 2005 by astronomer Michael T. Read using the Spacewatch 36-inch telescope on Kitt Peak National Observatory. It has an orbit within the asteroid belt and has displayed the coma of a traditional comet. It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter).
Before it was discovered 238P came to perihelion on 2005 July 27. When it was discovered on 2005 October 24, it showed vigorous cometary activity until 2005 December 27. Outgassing likely began at least 2 months before discovery. The activity of 238P is much stronger than 133P/Elst-Pizarro and 176P/LINEAR. This may indicate that the impact assumed to have triggered 238P's activity occurred very recently.
238P/Read was the target of a mission proposal in NASA's Discovery Program in the 2010s called Proteus, however it was not selected for further development. Discovery program's founding mission was to an asteroid, but it went to a Near-Earth asteroid. A mission to a main-belt asteroid was proposed in the 1990s (also see Deep Impact (spacecraft)).
- Henry H. Hsieh (May 2010). "Main Belt Comets". Hawaii. Archived from the original on 2011-08-06. Retrieved 2010-12-15. (older 2010 site) Archived August 10, 2009, at the Wayback Machine.
- David Jewitt. "Main Belt Comets". UCLA, Department of Earth and Space Sciences. Retrieved 2010-12-15.
- "JPL Small-Body Database Browser: 238P/Read (2005 U1)" (last observation: 2011-09-14). Archived from the original on 2012-08-09. Retrieved 2012-08-08.
- Hsieh, Henry H.; Jewitt; David C.; Ishiguro, Masateru (2009). "Physical Properties of Main-Belt Comet P/2005 U1 (Read)". The Astronomical Journal. 137 (1): 157–168. arXiv:0810.1351. Bibcode:2009AJ....137..157H. doi:10.1088/0004-6256/137/1/157. Retrieved 2010-12-18.
- Syuichi Nakano (2010-08-20). "P/Read (2005 U1 = 2010 N2)". OAA Computing and Minor Planet Sections. Retrieved 2011-07-25.
- "238P/Read Orbit". Minor Planet Center. Retrieved 2014-06-20.
- "PROTEUS – A MISSION TO INVESTIGATE THE ORIGIN OF EARTH'S WATER: CREATING HABITABLE WORLDS" (PDF). Astrobiology Science Conference 2015. Retrieved January 11, 2016.
- Discover 95 : MISSIONS TO THE MOON, SUN, VENUS AND A COMET PICKED FOR DISCOVERY - NASA
- Orbital simulation from JPL (Java) / Horizons Ephemeris
- Elements and Ephemeris for 238P/Read[permanent dead link] – Minor Planet Center
- 238P/Read at the Minor Planet Center's Database
- Main-Belt Comet 238P/Read Revisited (arXiv:1106.0045 : 31 May 2011)