For 30 years, a large near-Earth asteroid wandered its lone,
intrepid path, passing before the scrutinizing eyes of scientists while keeping
something to itself: 3552 Don Quixote, whose journey stretches to the orbit of
Jupiter, now appears to be a comet.
The discovery resulted from an ongoing project led by
researchers at Northern Arizona University using the Spitzer Space Telescope.
Through a lot of focused attention and a little bit of luck, they found
evidence of cometary activity that had evaded detection for three decades.