Comet Lovejoy reaches a pivotal point in its orbit next week when it comes closest to the sun. It will still be visible to earthbound skygazers, astronomers say.
While not a sun-grazer like its sibling comet, ISON, which flew into the sun and vaporized last month, Lovejoy is expected to reach so-called perihelion on Christmas Day.
"When the comet comes close to the sun, the solar winds push material off of it," said Jin Koda, an assistant professor in the department of astronomy and physics at Stony Brook University. Those winds force dust, ice and vapors off the core into the characteristic tail. Koda has captured some of the world's best photos of Lovejoy's journey.
Last week, the comet could be spotted near the Big Dipper's handle. But it's moving at nearly 300 miles per second and can now be spotted near an entirely different star cluster -- Hercules.
Experts recommend evening viewing because the moon may hinder a good sighting before dawn. With a pair of binoculars Lovejoy should be easily visible around 6:30 p.m. until the end of the year.
"If you're looking east, the Big Dipper is scraping the horizon and its bowl is pointing on an angle up near the North Star," said comet tracker Dan Malerbo, an astronomer with the Buhl Planetarium and Observatory in Pittsburgh.
"Hercules is located to the left of the Big Dipper and has the shape of a keystone," he said. "This comet isn't getting too close to the sun. ISON was about 700,000 miles from the sun. This one is 70 million miles away."