Comet Holmes, a usually faint sky object discovered more than 100 years ago, suddenly and inexplicably brightened about a millionfold late last month and can now be easily seen most clear nights with the naked eye.
"It's in a region of the sky where it is really easily seen," said George Masterson, Newburyport High School physics and astronomy teacher. "They say you can see it with the naked eye, and you can, but you get a much better view with binoculars."
Holmes, which has a fuzzy, star-like appearance, can been easily seen in the northeastern sky away from the lights of Boston and large cities. It will appear as a large, hazy spot near the constellation Cassiopeia.
The sudden clear appearance of the comet is due to its shell breaking away and the exposure of its internal gasses while it travels in orbit, Masterson said. "It's unique because it doesn't look like a comet with the typical tail; it looks like a cloud. It's not what you would normally see at all," Masterson said.
Masterson has used the comet as a teaching tool lately in his astronomy classes and club.
"It's great because it's something I've taught them about that is tangible now that they can see it," he said. "It's not like when you talk about distant galaxies and they don't see it."
The comet will only be visible for another 10 days, but the best views will be over the next few days during the new moon phase, since there is little competing light from the moon and the sky appears darker, Masterson said.
"With the naked eye, it looks like a star or planet, but with binoculars it's really weird looking; it doesn't happen every day," Masterson said.
Holmes was discovered in 1892 by British astronomer Edwin Holmes, but has never before been so bright. No one knows for sure what caused the cloud of gas or dust to be emitted from the comet's nucleus, but that is what is reflecting the sunlight and causing the intense brightness. As the comet enlarges, it will lose brightness and disappear from sight.
In general, comets are referred to as "dirty snowballs," a mixture of ice, frozen gas and dust that for some reason did not get incorporated into planets. Comets are only seen from Earth when they orbit close to the sun, and many comets have orbits that stretch beyond Pluto and so are seen only once every millennium or from Earth. Other comets, such as Halley's comet, have smaller orbits and are seen more often, according to NASA.
"They come from Kuiper Belt, which is past our solar system and full of rocks and debris," Masterson said. "It takes hundreds of years for them to orbit past the sun, so that is why we don't see things like this often. It's a great reason to get outside and take a look."
The Holmes Comet can be seen in the northeastern part of the sky under clear conditions, beginning around 6 p.m. It is between the bright star Capella and the constellation Cassiopeia. While it can be seen with the naked eye, binoculars are recommended for a great view.