Pallas’ Paths Might not be as Smart
Dubbed after the Greek goddess of wisdom, Pallas acts with the least wisdom of any asteroid. Its insane trajectory suggests it is enigmatically weird, as scientists explain in a statement: “While most objects in the asteroid belt travel roughly along the same elliptical track around the sun, much like cars on a racecourse, Pallas’s tilted orbit is such that the asteroid has to smash its way through the asteroid belt at an angle. Any collisions that Pallas experiences along its way would be around four times more damaging than collisions between two asteroids in the same orbit.”
“Pallas’ orbit implies very high-velocity impacts,” said Dr. Michaël Marsset, lead author the paper and a postdoctoral associate in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “From these images, we can now say that Pallas is the most cratered object that we know of in the asteroid belt. It’s like discovering a new world.”
Pallas was back in 1802, the second asteroid to be identified. It was easily detectable, considering the fact that it has about seven percent of the total mass in the asteroid belt. The space rock has an approximate diameter of about 513 kilometers, which is around 15 percent of the size of the Moon.
The team of researchers collected images of Pallas utilizing the SPHERE instrument at the European Southern Observatory’s Very Large Telescope (VLT), a network of telescopes based in the mountains of Chile.
The Most Beaten-Up Asteroid in the Solar System
Back in 2017, then in 2019, Dr. Marsset and his colleagues tried for several days at once to spot images of Pallas at a point in its orbit that was closest to our planet. From 11 series of photographs that captured the asteroid from various angles as it rotated, the team created a 3D reconstruction of the form of Pallas, together with a crater map.
They detected 36 craters more massive than 30 kilometers in diameter, ‘about one-fifth the diameter of Earth’s Chicxulub crater, the original impact of which likely killed off the dinosaurs 65 million years ago.’
Most of the craters were estimated to be at least 40 kilometers wide. To understand how dramatic the history of the asteroids has been, researchers ran a set of simulations of Pallas and its engagements with the rest of the asteroid belt throughout the last four billion years, about the age of the Solar System. They discovered that a 40-kilometer crater on the asteroid ‘could be made by a collision with a much smaller object compared to the same size crater on either Ceres or Vesta.’
The team’s paper result reads: “Pallas experiences two to three times more collisions than Ceres or Vesta, and its tilted orbit is a straightforward explanation for the very weird surface that we don’t see on either of the other two asteroids.”