Comet NEOWISE, the ‘Cosmic Snowball’

For most of July, observers have been catching a glimpse of the Comet NEOWISE in the night sky. Discovered on March 27 by NASA’s Wide-field Infrared Survey Explorer space telescope, the comet is currently visible in the Northern Hemisphere just after sunset below the Ursa Major constellation. On clear nights, NEOWISE can be seen over the Dartmouth campus and around the Upper Valley.

Comets are composed of ice, rock, and dust, which is why they are often called “cosmic snowballs,” according to Space.com. As these objects orbit the sun, they heat up and begin to emit tails, one made of dust and gas and another made of ions. In addition to the two common tails, NEOWISE has a third sodium tail, which has been observed only in bright comets like Hale-Bopp, the website says.

Skywatchers will be able to see NEOWISE until at least July 23, when it makes its closest approach to Earth. NASA says it won’t return to our skies for another 6,800 years.

Photos
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Comet Neowise over campus panoramic
Comet NEOWISE crosses the sky above campus. (Photo by Eli Burakian ’00)
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Comet over Connecticut river and lights of passing car
From the field of Dartmouth’s Organic Farm the comet is visible across the Connecticut River, above trees lit by a passing car on Vermont’s Route 5. (Photo by Eli Burakian ’00)
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Comet over the barn at the Organic Farm
NEOWISE streaks by the barn at the Organic Farm, which is softly lit by an oncoming car. (Photo by Eli Burakian ’00)
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Comet over Connecticut River with house lights reflecting
The comet appears over Route 5, with house lights reflected in the Connecticut River. (Photo by Eli Burakian ’00)
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Comet over a field of kale at the Organic Farm
NEOWISE flies over a field of kale at the Organic Farm. (Photo by Eli Burakian ’00)
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Comet over greenhouse
NEOWISE travels over the Organic Farm’s barn and greenhouse, which is lit by an exit sign. (Photo by Eli Burakian ’00)
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Two people viewing Comet Neowise from atop Gile Mountain
Two Dartmouth staff members view the comet from the summit of Gile Mountain in Norwich. (Photo by Robert Gill)
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Comet Neowise over Baker Tower
NEOWISE passes above Baker Tower. (Photo by Eli Burakian ’00)