See Nishimura In MA: Rare Green Comet Hurtling Toward Earth

MASSACHUSETTS — Stargazers in Massachusetts still have a few opportunities to see a newly discovered green comet hurtling along a path that will take it close to Earth and the sun before it disappears for another 400-plus years.

Comet Nishimura, discovered Aug. 11 by Japanese amateur astronomer Hideo Nishimura, is already visible from Earth but will make its closest approach to our planet on Tuesday. But the best chances to see it may be Sunday, when it makes its closest approach to the sun and reaches peak brightness.

The National Weather Service’s seven-day outlook calls for mostly cloudy skies on Tuesday. But the forecast could be better for Sunday's viewing with only partly-cloudy skies.

During its close approach to Earth, the half-mile-wide comet will still be 78 million miles away. It’s visible to the naked eye, but “you really need a good pair of binoculars to pick it out and you also need to know where to look,” Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies, told The Associated Press.

To see the comet, look toward the northeastern horizon about an hour and a half before dawn. Weather conditions permitting, the comet will be about 10 degrees above the horizon near the constellation Leo. The comet will brighten as it gets closer to the sun, but will drop lower in the sky, making it tricky to spot.

The comet will come closest to the sun — closer than Mercury is — on Sunday before departing the solar system. That's assuming it doesn’t disintegrate when it buzzes the sun, though Chodas said “it’s likely to survive its passage.”

Italian astronomer Gianluca Masi, founder of the Virtual Telescope Project, told AP in an email that this week represents “the last, feasible chances” to see the comet from the Northern Hemisphere before it’s lost in the sun’s glare.

“The comet looks amazing right now, with a long, highly structured tail, a joy to image with a telescope,” he said of the rare green comet.

It’s unusual for an amateur to discover a comet these days, given all the professional sky surveys by powerful ground telescopes, Chodas said, adding, “this is [Nishimura’s] third find, so good for him.”

The comet last visited about 430 years ago, Chodas said. That's about a decade or two before Galileo invented the telescope.

The Associated Press contributed reporting.