The Hubble Telescope, operated by the ESA and NASA, has caught never-before-seen images of an asteroid breaking-up. The asteroid, designated P/2013 R3, broke up into at least ten pieces.
One of a kind images
Asteroids with fragile nuclei can break apart as they approach the sun, but this process has never been seen before in the asteroid belt. The asteroid was first discovered in Sepembr. 2013, by Earth-based observatories. It first appeared as a fuzzy and unusual looking object.
Follow-up images revealed the asteroid was actually three separate bodies in an envelope of dust similar in size to the diameter of Earth. These images convinced astronomers to examine the asteroid using the Hubble telescope. These images were taken using the KECK telescope in Hawaii.
The YORP effect
The better pictures will help scientists better understand how asteroids break up.
“This is a really bizarre thing to observe — we’ve never seen anything like it before, the break-up could have many different causes, but the Hubble observations are detailed enough that we can actually pinpoint the process responsible,” said co-author Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany.
Scientists theorize that the asteroid break-up is caused by centrifugal force and a fractured interior. This phenomenon is known as the YORP effect and has been theorized for several years, but it has never been reliably observed.
Scientists believe that sunlight causes the rotation of the asteroid to slowly increase over time. This slow increase causes the centrifugal force to increase, and slowly pulls the asteroid apart. This theory relies on the asteroid having a fractured interior. Researchers believe that this could happen from collisions with smaller asteroids.
Solving the mystery
The images from Hubble reveal that the asteroid began breaking up early last year and new fragments are still emerging. The continuing emergence of new fragments tells scientists the break-up was not caused by a collision with another asteroid. If two asteroids were to collide the disintegration would be instantaneous and violent.
The pieces of the asteroid are drifting apart more slowly than the average walking pace, at a velocity of approximately 1.5 km/h. If the asteroid had experienced a collision then the pieces would be travelling at a much faster velocity.
Asteroids commonly break up when they approach the sun as the ice at the core begins melting and vaporising. This can cause an asteroid to break apart as the interior pressure builds, similar to the top being blown off a Coke can when a Mentos is dropped in.