Two Sungrazer Comets Being Devoured by Sun Captured by NASA Probe

Footage of two comets plunging into the surface of the sun was taken by a NASA probe on October 22.

Captured by the Solar and Heliospheric Observatory (SOHO) spacecraft, which was launched by NASA and the European Space Agency in 1995, coronagraph footage shows the two "Kreutz sungrazer" comets heading straight towards the sun.

Kreutz sungrazers are a group of comets that have a very similar orbit, many of which fall into the sun. It is thought that they all come from a progenitor comet that broke up, forming thousands of smaller fragment comets.

"What makes Kreutz comets unusual is that they all have the same (or very close) orbit, so we think they are fragments of a parent comet that previously disrupted," Tabare Gallardo, an astronomer at the Universidad de la República in Uruguay, told Newsweek. "It is unclear when that disruption occurred."

"Saturday's bright comet turned out to have a smaller, leading companion," Karl Battams of the U.S. Naval Research Lab told spaceweather.com. "This isn't particularly uncommon. I'd estimate that at least 30 percent of the really bright sungrazers we see in SOHO coronagraph images end up having a small leading or trailing companion."

Kreutz sungrazers have been observed throughout recorded history. The original comet is thought to have been the Great Comet of 371 BC, which appeared brighter than all the stars in the sky. Assuming that this was the progenitor of the Kreutz sungrazers, scientists estimate that this comet may have had a diameter of over 75 miles.

Other bright comets over the centuries have since been associated with Kreutz sungrazers, including the Great Comet of 1843, the Great Comet of 1882 and X/1106 C1, all of which were visible even during the daytime.

Over 4,000 Kreutz fragments have been observed falling into the Sun by SOHO.

"[The Kreutz sungrazers] move around the sun in elliptic or hyperbolic orbits. One of the points of the ellipse or hyperbola is the point closest to the sun. The distance of this point from the center of the sun is the perihelion distance. If this distance is smaller than the solar radius, then the comet nucleus necessarily dives into the sun. An orbital stability or instability is not important here," Lubos Neslusan, an astronomer at the Slovak Academy of Sciences, told Newsweek.

According to spaceweather.com, astronomers have been keeping watch for a larger group of Kreutz comets colliding with the Sun in tandem, but no big cluster collisions have yet been observed.

"We have absolutely no idea what the actual distribution of Kreutz comets looks like around their orbit," Battams said. "Undoubtedly there are clusters, but it's a several-century-long path they're following and we've only been blessed with a [roughly] 25-year window into that. So all we can do is just keep watching and counting."

Most other comets are in a less elliptical orbit around the sun, rarely falling into the star.

"Most comets do not plunge into the sun, at least not in the short term. However, it is thought that most comets and asteroids do end up colliding with the sun eventually, but this process is estimated to take millions of years," Paul Wiegert a physicist and astronomer at the University of Western Ontario, told Newsweek.

As the comets hit the Sun, they are thought to be vaporized by the scorching surface temperatures, which reach up to 5,778 K, or 9,941°F.

"No one knows exactly what happens to the material that falls to the Sun, presumably it disintegrates completely. There are observations in the spectra of other stars that support the idea that some material is falling, some researchers think it could be populations of comets and asteroids falling on the star," Gallardo said.