Hubble discovers smallest Kuiper Belt object ever seen

Washington, December 17 (ANI): NASA's Hubble Space Telescope has discovered the smallest object ever seen in visible light in the Kuiper Belt.

The Kuiper Belt is a vast ring of icy debris that is encircling the outer rim of the solar system just beyond Neptune.

The needle-in-a-haystack object found by Hubble is only 3,200 feet across and a whopping 4.2 billion miles away.

The smallest Kuiper Belt Object (KBO) seen previously in reflected light is roughly 30 miles across, or 50 times larger.

This is the first observational evidence for a population of comet-sized bodies in the Kuiper Belt that are being ground down through collisions.

The object detected by Hubble is very faint, and at 35th magnitude, it is 100 times dimmer than what the Hubble telescope can see directly.

Hilke Schlichting of the California Institute of Technology in Pasadena, California, and her collaborators are reporting that the telltale signature of the small vagabond was extracted from Hubble's pointing data, not by direct imaging.

Hubble has three optical instruments called Fine Guidance Sensors (FGS).

The FGSs provide high-precision navigational information to the space observatory's attitude control systems by looking at select guide stars for pointing.

The sensors exploit the wavelike nature of light to make precise measurement of the location of stars.

Schlichting and her co-investigators determined that the FGS instruments are so good that they can see the effects of a small object passing in front of a star.

In an effort to uncover additional small KBOs, the team plans to analyze the remaining FGS data for nearly the full duration of Hubble operations since its launch in 1990. (ANI)