There is a link to the press release[1] the bottom left, next to where it says "source" - All Engadget posts have it in the same place. Seemingly it's not prominent enough, but the attribution is certainly there.
While true, it looks identical to the "NASA" link that precedes it that doesn't go externally, and so I skipped over it as I thought it was a duplicate.
Besides, is it possible to make an attribution less visible?
[1] http://www.nasa.gov/topics/universe/features/universe2011072...