Photo reblogged from The Urania Project with 588 notes
“Four Planet Sunset” (via APOD: July 31, 2010)
Source: uraniaproject
Photo with 3 notes
NASA’s Hubble Space Telescope observed what, at the time was known as the “tenth planet,” nicknamed “Xena,” for the first time and has found that it is only just a little larger than Pluto. Though previous ground-based observations suggested that Xena was about 30 percent greater in diameter than Pluto, Hubble observations taken on Dec. 9 and 10, 2005, yield a diameter of 1,490 miles (with an uncertainty of 60 miles) for Xena.
Click to enlarge.
Source: a52.g.akamaitech.net
