A space tourist who takes you back to the past-a light green comet

A huge comet with green light quietly broke through the night sky, and some people jokingly called it "Hulk Comet". According to Sky and Telescope magazine, this celestial body is closest to the Earth on this day. This is the first time that this comet has visited the solar system.

The official name of this comet is rather boring, called C/20 17 S3. It was first observed by the pan-satellite project telescope of Haleakala Observatory in Maui, Hawaii on February 23rd, 20 17. According to Sky and Telescope, this flying green meteorite gave many surprises to astronomy lovers, and its surface burst into bright light twice in a row. Maybe the Hulk will also say, "Comet twinkles!"

Although the cause of the explosion has not been ascertained, such an explosion is very common for comets. For many years, scientists thought that these explosions happened in this way. When a comet leaves Pluto's outer space and intrudes into the solar system, its surface overheats and its internal pressure increases, leading to its geyser-like explosion. However, according to Live Science, the Rosetta spacecraft has different views on the close observation of comet 67P, that is, landslides will raise dust and other substances on the steep slope of the comet and fly into space.

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According to the analysis of Austrian amateur astronomer Michael Jagger, regardless of the original size of C/20 17 S3, the second eruption will produce a huge gas cloud around this icy meteorite, and its volume will be nearly twice that of Jupiter, about 16 1000 miles (260,000 kilometers). Brian Kabring, an astrophysicist at Rochester Institute of Technology in new york, wrote in his blog that this is how the green hue of comet Hulk was generated. The cyanide and carbon molecules contained in the comet are ionized by the sun, and the electrons and protons are separated from each other, resulting in such a characteristic glow.

It is reported that a Russian scientist was quoted as saying that this "pleasant" green comet will bring catastrophic upheaval to the earth. But don't worry, just like its nickname superhero Hulk, this comet is more harmless than it looks. But stanislav, a Russian astronomer at the Tau Observatory, said that this comet does not pose any threat, and this kind of object often passes near our planet without any accident.

Paul Jordas, director of the Near-Earth Object Research Center of the Jet Propulsion Laboratory, told us that comet Hulk was about1.1.200 million kilometers away from the Earth when it was closest to the Earth, and then it flew towards the sun, orbiting our central star, and then quickly returned to a place far away from the solar system. It will be too close to the sun to be visible, but it can be observed again when it ends its journey to the sun and returns.

Extended reading of related knowledge

A comet is a small solar system body (SSSB) made of ice. When it approaches the sun, it will be heated and begin to release gas, showing a visible atmosphere, that is, coma, and sometimes a tail. These phenomena are caused by the joint action of solar radiation and solar wind on the comet nucleus. Comet nuclei are composed of loose ice, dust and small rocks, ranging in size from several hundred meters in P/2007 R5 to dozens of kilometers in Comet Haier Popper, but most of them will not exceed 16 kilometers.

Illustration: The spacecraft visited the nucleus of 103P/ Hadley and the jet it caused. The length of the nucleus is about 2 kilometers, and the narrowest part is only about 400 meters wide.

The orbital period of comets is also very large, ranging from several years to millions of years. Short-period comets come from the Kuiper Belt outside Neptune's orbit or are related to discrete disks. Long-period comets are thought to originate from Oort Cloud, which is a spherical shell composed of frozen objects outside the Kuiper Belt, extending to half the distance of the nearest star. Long-period comets are disturbed by the gravity of passing stars and the galactic tides and rush directly to the sun. Comets with hyperbolic orbits may have been ejected into interstellar space along hyperbolic orbits before entering the solar system, but they will only cross the solar system once. Strange comets from outside the solar system, which may be common in the Milky Way, have also been detected.

reference data

1. Wikipedia

2. Astronomical terminology

3. Adam Mann-Morris

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