Artists concept of smallest KBO. Click for larger. Credit: NASA, ESA, and G. Bacon (STScI) Science Credit: NASA, ESA, and H. Schlichting (Caltech)

The image shown here is an artist concept depicting Hubble’s detection of the smallest Kuiper Belt Object or KBO yet found.

You might be wondering why there is an artists concept and not the actual image.  The object, just 3,200 feet across, is estimated to be 4,200,000,000 miles away and “shines” at 35th magnitude that’s 100 times fainter than even Hubble can see!!  I guess “shines” isn’t really a good term, but you know what I mean.

The image was found by it occultation of a star.  The KBO passed in front of a star causing it to wink out briefly.  By knowing the instrument on Hubble samples changes 40 times a second, the researchers involved determined the event to last 0.3 seconds so they could calculate how large something would be to have to be.

Read the full story here at the Hubble page.