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Sungrazing comets are a special class of comets that come very close to the sun at their nearest approach, a point called perihelion. To be considered a sungrazer, a comet needs to get within about 850,000 miles from the sun at perihelion. Many come even closer, even to within a few thousand miles. Being so close to the sun is very hard on comets for many reasons. They are subjected to a lot of solar radiation which boils off their water or other volatiles. The physical push of the radiation and the solar wind also helps form the tails. And as they get closer to the sun, the comets experience…
![What is a Sungrazing Comet? [hd video]](https://images-assets.nasa.gov/image/GSFC_20171208_Archive_e001302/GSFC_20171208_Archive_e001302~orig.jpg)
