Discovery [1] | |
---|---|
Discovered by | LINEAR ( 704) |
Discovery date | 6 January 2010 |
Designations | |
Orbital characteristics [3] | |
Epoch 13 October 2010 ( JD 2455482.5) | |
Aphelion | 2.58 AU (Q) |
Perihelion | 2.01 AU (q) |
2.29 AU (a) | |
Eccentricity | 0.1246 |
3.47 yr | |
88.9° (M) | |
Inclination | 5.25 ° |
320° | |
2023-Oct-13 [4] | |
133° | |
Physical characteristics | |
Dimensions | 172.4 × 88.8 m [5] |
Mean diameter | 123.8+33.6 −18.4 m [5] |
11.36±0.02 h | |
Albedo | unknown |
~18-20 [1] | |
21.3±0.6 [6] | |
354P/LINEAR, provisionally designated P/2010 A2 (LINEAR), is a small main-belt asteroid that was impacted by another asteroid sometime before 2010. It was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) at Socorro, New Mexico on 6 January 2010. The asteroid possesses a dusty, X-shaped, comet-like debris trail that has remained nearly a decade since impact. [5] This was the first time a small-body collision had been observed; since then, minor planet 596 Scheila has also been seen to undergo a collision, in late 2010. The tail is created by millimeter-sized particles being pushed back by solar radiation pressure. [7] [8]
P/2010 A2 was discovered on 6 January 2010 by Lincoln Near-Earth Asteroid Research (LINEAR) using a 1-meter (36") reflecting telescope with a CCD camera. [1] It was LINEAR's 193rd comet discovery. [9] [10] It has been observed over a 112-day arc of the 3.5 year orbit. [3] It appears to have come to perihelion (closest approach to the Sun) around the start of December 2009, [3] about a month before it was discovered.
With an aphelion (furthest distance from the Sun) of only 2.6 AU, [3] P/2010 A2 spends all of its time inside of the frostline at 2.7 AU. [11] Beyond the frostline volatile ices are generally more common. Early observations did not detect water vapor or other gases. [12] Within less than a month of its discovery it was doubtful that the tail of P/2010 A2 was generated via active outgassing from sublimation of ices hidden beneath the crust. [13] Early modeling indicated that the asteroid became active in late March 2009, reached maximum activity in early June 2009, and eased activity in early December 2009. [14]
Observations with the Hubble Space Telescope [15] and the narrow angle camera on board the Rosetta spacecraft [16] indicate that the dust trail seen was probably created by the impact of a small meter size object on the larger asteroid in February or March 2009, although it cannot be ruled out that the asteroid's rotation increased from solar radiation resulting in a loss of mass that formed a comet-like tail. [17]
P/2010 A2 is likely about 150 meters (460 feet) in diameter. [12] Even when it was discovered it was suspected of being less than 500 meters in diameter. [18]
The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. [12] The Flora family of asteroids may be the source of the Chicxulub (Cretaceous–Paleogene) impactor, the likely culprit in the extinction of the dinosaurs. [12]
Debris field
P/2010 A2 is likely the debris left over from a recent collision between two very small asteroids. |
Surviving fragment
Surviving fragment seen to the lower left of debris field |