Astronomers Have Discovered a Surprise Asteroid Orbiting Closer to The Sun Than Venus

Astronomers have painstakingly crafted styles of the asteroid population, and those people styles predict that there will be ~one km sized asteroids that orbit nearer to the Solar than Venus does. The problem is, nobody’s been equipped to locate one. Until eventually now.


Astronomers operating with the Zwicky Transient Facility say they’ve at last observed one. But this one’s greater, at about two km. If its existence can be verified, then asteroid population styles may perhaps have to be current.

A new paper presenting this consequence is up on arXiv, a pre-push publication internet site. It really is titled “A kilometer-scale asteroid inside of Venus’s orbit”. The guide writer is Dr. Wing-Huen Ip, a Professor of Astronomy at the Institute of Astronomy, Countrywide Central University, Taiwan.

Graphic demonstrates 2020 AV2’s, Earth’s, Venus’ and Mercury’s orbits. (Ip et al., arXiv,2020)

The newly-learned asteroid is named 2020 AV2, has an aphelion distance of only .65 astronomical units, and is about two km in diameter. 

Its discovery is stunning considering that styles predict no asteroids this huge inside of Venus’ orbit. It could be proof of a new population of asteroids, or it could just be the most significant of its population.

The authors write that: “If this discovery is not a statistical fluke, then 2020 AV2 may perhaps appear from a nevertheless undiscovered source population of asteroids inside to Venus, and now favored asteroid population styles may perhaps will need to be adjusted.”


There are about one million regarded asteroids, and the vast the vast majority of them are well outside the house Earth’s orbit. There are only a tiny fraction located with their full orbits inside of Earth’s.

Versions predict that an even scaled-down number of asteroids really should be inside of Venus’ orbit. People asteroids are called Vatiras.

2020 AV2 was 1st noticed by the Zwicky Transient Facility (ZTF) on four January 2020. Adhere to-up observations with the Palomar sixty-inch telescope and the Kitt Peak 84-inch ‘scope collected a lot more details.

In close proximity to the end of January, astronomers applied the Keck Telescope for spectroscopic observations of the rock. That details demonstrates that the asteroid arrived from the inner location of the main asteroid belt, involving Mars and Jupiter.

“These details favor a silicate S-variety asteroid-like composition consistent with an origin from the inner Principal Belt the place S-variety asteroids are the most plentiful.” They insert that it agrees with In close proximity to Earth Asteroid (NEA) styles that “…predict asteroids with the orbital factors of 2020 AV2 should originate from the inner Principal Belt.”

2020 AV2 is both a model-buster or a model-confirmer.

“NEA population styles predict <1 inner-Venus asteroid of this size implying that 2020 AV2 is one of the largest inner-Venus asteroids in the Solar System," the authors write.


It really is both the most significant one, which tends to make sense since the most significant one would be the 1st to be noticed, or there are a lot more of them that we have not observed nevertheless.

The authors assumed by two situations involving 2020 AV2’s detection, and what it usually means.

“Irrespective of its minimal probability, a feasible rationalization for our detection of 2020 AV2 is a random prospect discovery from the nearEarth asteroid population,” they write.

“Even so,” they continue on, “heritage has shown that the 1st detection of a new course of objects is usually indicative of one more source population c.f., these types of as the Kuiper Belt with the discovery of the 1st Kuiper Belt Objects 1992 QB1 and 1993 FW.”

You can find also a probability that 2020 AV2 didn’t originate in the primary asteroid belt. Versions present that there is a location inside of Mercury’s orbit that could have spawned asteroids, and the place they could still reside. “…2020 AV2 could have originated from a source of asteroids located nearer to the Solar, these types of as in the vicinity of the balance areas located inside of the orbit of Mercury at au the place huge asteroids could have fashioned and survived on time scales of the age of the Photo voltaic System.”


2020 AV2 might not expend an eternity on its current orbit. The group of researchers performed some simulations, and they present that the asteroid could be ejected from the Photo voltaic System completely. “… dynamical N-body simulations of 2020 AV2 reveal that its orbit is secure on ~ten Myr timescales, moving into into non permanent resonances with the terrestrial planets and Jupiter ahead of its orbit evolves on to shut-encounter paths with the fuel large primary to its eventual ejection from the Photo voltaic System.”

When 2020 AV2 was 1st learned, experts questioned at the journey it should have taken to get there. They also questioned about is eventual destiny.

“Getting previous the orbit of Venus should have been challenging,” said George Helou, government director of the IPAC astronomy centre at Caltech and a ZTF co-investigator, in a press release.

Helou spelled out that the asteroid should have migrated in towards Venus from farther out in the solar procedure.

“The only way it will ever get out of its orbit is if it gets flung out through a gravitational encounter with Mercury or Venus, but a lot more most likely it will end up crashing on one of those people two planets.”

If this discovery is just the 1st of a entire population of asteroids inside of Venus’ orbit, the the vast majority of them will all share the exact destiny. Immediately after about ten to 20 million years, they’ll all be ejected.

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