Back in March, I made several posts about Sedna, a planetoid discovered at the edge of our solar system. NASA was able to target Sedna with the Hubble Space Telescope this week; here is the official press release, and here is a page with the images captured by the telescope. After reviewing the Hubble images, astronomers concluded that Sedna could be no more than 1,000 miles in diameter (about ¾ the size of Pluto) but were very surprised to find that no moon was present. Apparently, Sedna’s extremely slow rotation, measured at a period of 40 days, is anomalous for a body that small, and astronomers expected to see that a “companion object’s” gravitational tug was the cause. It seems that although these images have revealed a lot about Sedna, there are still mysteries left to explore.
