First detailed images of asteroid UW158 proves it isn’t an average one

Credit: Steven M. Tilley

Images of asteroid (436724) 2011 UW158 captured by scientists from the Arecibo Observatory reveal that the space rock isn’t an average asteroid with an odd shape resembling an unshelled walnut with a diameter of 300 by 600 meters (1,000 by 2,000 feet).

The observations made on July 14 from a distance of 6.9 million kilometers away (4.3 million miles) also reveal that the asteroid rotates very rapidly, once every 37 minutes, which agrees with previous optical observations.

The observations were made on the same day as New Horizons made its closest ever flyby of Pluto. Researchers reveal that this is something more than gravitation at play as far as UW158 is concerned otherwise the asteroid would break up due to its fast spin.

Dr. Patrick Taylor, a scientist in the Planetary Radar department and lead of the observations, explains that one of the possibility could be that the asteroid is one solid body rather than many smaller rocks held together by gravity. Only two other asteroids this large and rotating this fast have been observed before.

Dr Taylor explained that it is surprising that something big of this size has survived for this long and it will be making a similar flyby Earth in 2108 – something that scientists consider a potential threat.

“Such observations provide clues to how asteroids formed and changed over time,” added Dr. Edgard Rivera-Valentin, a member of the Planetary Radar department and part of the observation team. The group of observers also included project specialist Linda Ford and Benjamin Sharkey, a student in the educational research program Research Experience for Undergraduates, funded by the National Science Foundation.