It is called Comet Elenin.
Latest indications are this relatively small comet has broken into even smaller, even less significant, chunks of dust and ice. This trail of piffling particles will remain on the same path as the original comet, completing its unexceptional swing through the inner solar system this fall.
“Elenin did as new comets passing close by the sun do about two percent of the time: It broke apart,” said Don Yeomans of NASA’s Near-Earth Object Program Office in Pasadena, Calif. “Elenin’s remnants will also act as other broken-up comets act. They will trail along in a debris cloud that will follow a well-understood path out of the inner solar system. After that, we won’t see the scraps of comet Elenin around these parts for almost 12 millennia.”
Twelve millennia may be a long time to Earthlings, but for those frozen inhabitants of the outer solar system who make this commute, a dozen millennia give or take is a walk in the celestial park. Comet Elenin came as close as 45 million miles (72 million kilometers) to the sun, but it arrived from the outer solar system’s Oort Cloud, which is so far away its outer edge is about a third of the way to the nearest star other than our sun.
For those broken up over the breakup of what was formerly about 1.2 miles (two kilometers) of uninspiring dust and ice, remember what Yeomans said about comets coming close to the sun – they fall apart about two percent of the time.
“Comets are made up of ice, rock, dust and organic compounds and can be several miles in diameter, but they are fragile and loosely held together like dust balls,” said Yeomans. “So it doesn’t take much to get a comet to disintegrate, and with comets, once they break up, there is no hope of reconciliation.”
More details, and pictures of the orbital geometry of the slush, here.