Welcome to the Comet Linear sky show.

Comet Linear, the brightest comet of the year, continues to surprise astronomers with its disappearing-act antics. This week, Linear has provided several observatories with dazzling images of its remains.

Though comets are known to break apart, astronomers have until now had very few observations of such dismantling events. For the past few weeks, Linear has provided researchers with myriad views of how comet nuclei disassemble. Now, images from the Hubble Space Telescope, the University of Hawaii, the European Southern Observatory and the Spanish Instituto de Astrofisica de Canarias have revealed that Comet Linears nucleus (icy core) has now completely broken up into tiny "mini-comets."

Experts say that Linears breakup is probably due to gradual heating from the sun. As comets get closer and closer to our home star, the suns energy causes gases in the comets nucleus to spray out into space as a visible head and tail. Linear seems to have gotten a bit too warm to remain intact, so its nucleus began blowing off pieces earlier this summer, eventually dissipating completely.

"What we are seeing now are the remnants of the nucleus," said Harold Weaver, a scientist at Johns Hopkins University who has been studying the icy visitor. These remnants are similar to small bodies called "cometesimals," of which comets are thought to originally be composed. Though they are broken apart, these small pieces, still warmed by the sun, spray ice and dust, and form a visible tail.

One factor contributing to Comet Linears breakup may be its relatively small size. Though astronomers dont yet have direct evidence of the comets exact size, they do have indirect evidence that the nucleus started out relatively small perhaps a mile or less across. Whats more, Linears far distance from Earth caused the comet to be invisible without the aid of at least a powerful pair of binoculars. "This comet seems to have been a real wimp," said Weaver.

Astronomers keeping an eye on Comet Linear say that its just a matter of time before its pieces dissipate completely. Its complete disappearance, they say, could take days or weeks. For now, all eyes will remain on this tumultuous target; the Hubble Space Telescope has already been scheduled for several more Linear observations.