Scientists search for moons around asteroids

October 6, 2011
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: Arecibo Observatory astronomers discover first near-Earth triple asteroid just 7 million miles away

Related Stories

How Kleopatra got its moons

February 23, 2011

The asteroid Kleopatra, like its namesake, the last pharaoh and queen of Egypt, gave birth to twins – two moons probably spawned by the asteroid sometime in the past 100 million years.

New horseshoe orbit Earth-companion asteroid discovered

April 6, 2011

(PhysOrg.com) -- Apostolos Christou and David Asher from the Armagh Observatory in Northern Ireland announced the discovery of an asteroid near Earth called Asteroid 2010 SO16 and their findings were published on arXiv.org. ...

3552 Don Quixote... leaving our solar system?

July 11, 2011

“Tell me thy company, and I’ll tell thee what thou art…” In this case it is Asteroid 3552 Don Quixote – one of the most well-known of Near Earth Asteroids. You may know its name, but did you know ...

Dust settles to reveal asteroid truth

September 15, 2011

(PhysOrg.com) -- Early results from analysis of dust on the Hayabusa space capsule, which landed in South Australia last year, have revealed an indisputable link between the asteroids we see in space and meteorites that we ...

Recommended for you

Image: Hubble sees a dying star's final moments

July 31, 2015

A dying star's final moments are captured in this image from the NASA/ESA Hubble Space Telescope. The death throes of this star may only last mere moments on a cosmological timescale, but this star's demise is still quite ...

Exoplanets 20/20: Looking back to the future

July 31, 2015

Geoff Marcy remembers the hair standing up on the back of his neck. Paul Butler remembers being dead tired. The two men had just made history: the first confirmation of a planet orbiting another star.

Earth flyby of 'space peanut' captured in new video

July 31, 2015

NASA scientists have used two giant, Earth-based radio telescopes to bounce radar signals off a passing asteroid and produce images of the peanut-shaped body as it approached close to Earth this past weekend.

Binary star system precisely timed with pulsar's gamma-rays

July 31, 2015

Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Jeddy_Mctedder
2.3 / 5 (3) 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

Click here to reset your password.
Sign in to get notified via email when new comments are made.