Fireworks in the Solar system – produced by our own Sun.

Astronomers using the Hubble Space  telescope this week reported the discovery of an asteroid emitting streams of dust in a spherical or ‘wheel-like’ pattern.

Usually asteroids are seen as points of life. This asteroid (P/2013 P5) is all the more intriguing given that the astronomers observed that the structure of its surrounding dust trails changed completely within the space of 13 days. This implies that the dust trails of asteroids are controlled by a dynamic and ongoing process.

Careful modelling by Jessica Agarwal from the Max Planck Institute for Solar system research in Lindau, Germany suggests that these streams of dust are the result of the asteroid breaking up and ejecting material from its surface in pulses. The radiative pressure caused by the Sun’s light then drags this material away from the asteroid into tail shapes. This radiative pressure is also believed to be responsible for the break up of the asteroid itself by influencing the asteroid’s spin rate to the point where the weak gravity field on the small asteroid (radius = 240m) is no longer able to hold the material together.

Although this is the first time that this phenomenon has be observed, David Jewitt from the Univeristy of California suggests that the rotational breakup of small asteroids may be common. Although Asteroid P/2013 P5 has only lost a fraction of its mass so far astronomers are monitoring the process closely in the hope of elucidating further the process of asteroid movement and break-up.

For more information: http://www.spacetelescope.org/news/heic1320/