The asteroid in query, known as (101429) 1998 VF31, is a part of a bunch of trojan asteroids sharing the orbit of Mars.
Trojans are celestial bodies that fall into gravitationally balanced areas of area within the neighborhood of different planets, situated 60 levels in entrance of and behind the planet.
What makes (101429) 1998 VF31 (hereafter ‘101429’) fascinating is that among the many Crimson Planet’s trailing trojans (those that observe behind Mars because it orbits the Solar), 101429 seems to be distinctive.
The remainder of the group, known as the L5 Martian Trojans, all belong to what’s generally known as the Eureka household, consisting of 5261 Eureka – the primary Mars trojan found – and a bunch of small fragments believed to have come free from their mum or dad area rock.
101429 is completely different, although, and in a new study led by astronomers from the Armagh Observatory and Planetarium (AOP) in Northern Eire, researchers needed to look at why.
Utilizing a spectrograph known as X-SHOOTER on the European Southern Observatory’s 8-m Very Giant Telescope (VLT) in Chile, the staff examined how daylight displays off 101429 and its L5 kin within the Eureka household. Solely, it seems to be like 101429 and the Eureka clan aren’t kin in any case, with the evaluation revealing 101429 reveals a spectral match for a satellite tv for pc a lot nearer to dwelling.
“The spectrum of this specific asteroid appears to be nearly a dead-ringer for components of the Moon the place there’s uncovered bedrock equivalent to crater interiors and mountains,” explains AOP astrochemist Galin Borisov.
Whereas we won’t be certain but why that’s, the researchers say it is believable that this Martian trojan’s origins started someplace far faraway from the Crimson Planet, with 101429 representing a “relic fragment of the Moon’s authentic strong crust”.
If that is true, how did the Moon’s long-lost twin find yourself as a trojan sure along with Mars?
“The early Photo voltaic System was very completely different from the place we see immediately,” explains lead writer of the examine, AOP astronomer Apostolos Christou.
“The area between the newly-formed planets was filled with particles and collisions had been commonplace. Giant asteroids [planetesimals] had been consistently hitting the Moon and the opposite planets. A shard from such a collision might have reached the orbit of Mars when the planet was nonetheless forming and was trapped in its Trojan clouds.”
It is a fascinating thought, however the researchers say it isn’t the one clarification for 101429’s previous. It is also attainable, and maybe extra probably, that the trojan as a substitute represents a fraction of Mars chipped off by the same sort of incident impacting the Crimson Planet; or it’d simply be a commonplace asteroid that, by way of the weathering processes of photo voltaic radiation, ended up trying identical to the Moon.
Additional observations with much more highly effective spectrographs may be capable of shed extra mild on this query of area parentage, as might a future spacecraft go to, the team says, “which might, en path to the Trojans, acquire spectra at Mars or the Moon for direct comparability with the asteroid information”.
The findings are reported in Icarus.