Blue asteroids are rare. An international team led by researchers at the University of Arizona's Lunar and Planetary Laboratory, studied (3200) Phaethon, a strange asteroid that at times behaves like a comet, and found it even more puzzling than formerly believed.
Phaethon sets itself apart for two reasons. It seems to be one of the "bluest" of similarly colored asteroids or comets in the solar system. And, its orbit takes it so close to the sun, that its surface heats up to about 800 degrees Celsius, hot enough to melt aluminum.
Phaethon constantly appears as a dot in the sky, like thousands of other asteroids, and not as a fuzzy blob with a tail, like a comet. But Phaethon is also the source of the annual Geminid meteor shower, observed in early-to-mid December.
Meteor showers occur when Earth passes through the trail of dust left behind on a comet's orbit. When they occur and where they appear to originate from hinges on on how the comet's orbit is oriented with respect to the Earth. Phaethon is thought to be the "parent body" of the Geminid meteor shower because its orbit is very similar to the orbit of the Geminid meteors. Until it was discovered in 1983, scientists associated all identified meteor showers to active comets, and not asteroids.
The team, based on the latest discoveries, believes that Phaethon might be related to a large blue asteroid, far out in the solar system. They also found that the asteroid is equally blue all-around.