Scientists search for moons around asteroids

Scientists search for moons around asteroids
Artistic impression of the asteroid Minerva.
(PhysOrg.com) -- Most people know that some planets have moons but would be surprised to know that some asteroids do, too. According to Joshua Emery, assistant professor of earth and planetary sciences at the University of Tennessee, Knoxville, about 20 percent of them do.

Emery is part of an international team of planetary astronomers, lead by Franck Marchis of the Carl Sagan Center of the in Mountain View, California, searching for moons around asteroids. The discovery of moons around asteroids is important because it can provide clues to the asteroid’s formation.

Emery and his team’s research have focused on the triple asteroid Minerva, the fourth asteroid located in the main-belt—which houses most of the solar system’s asteroids— known to possess two moons.

“Minerva was thought to be a pretty typical, unremarkable asteroid until we discovered its two moons,” said Emery. “Now, interest in this system has grown, and through a lot of new observations from both ground-based and space-based telescopes, we have developed a much more detailed understanding of Minerva and its moons.”

The team studied the asteroid in detail using the large W.M. Keck telescope in Hawaii and a small robotic telescope at Kitt Peak in Arizona. By piecing together old and new observations, the astronomers were able to make precise determinations of the moons’ orbits. With shape, size, and mass in hand, the scientists then derived the asteroid’s density—determining that Minerva is different than the other large asteroids in the main-belt.

“All other large main-belt asteroids with one or more moons are very porous,” said Emery. “Such high porosity strongly suggests that they are piles of rubble held together by gravity rather than solid rocks. Imagine an asteroid being completely blasted apart in a collision, then the pieces coalescing back together-–this is how we think most of these large, multiple asteroid systems, form. From these glimpses into the interior structure of asteroids, we gain insight not only into the history and formation of multiple systems but also the structure and origin of asteroids in general.”

The results of the group’s findings were released at the EPSC-DPS meeting in Nantes, France.


Explore further

How Kleopatra got its moons

Provided by University of Tennessee, Knoxville
Citation: Scientists search for moons around asteroids (2011, October 6) retrieved 21 May 2019 from https://phys.org/news/2011-10-scientists-moons-asteroids.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Oct 06, 2011
most people do not know that the biggest moon, jupiter's ganymede is bigger than mercury. i for one would like to see what would happen if it somehow fell into jupiter. what a show that would be.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more