Scientists used data from the very large Very Large Telescope of the European Southern Observatory (VLT ESO) and discovered two metals that are found on comets not only in the solar system, but also beyond.
A new study by Belgian scientists has shown that iron and nickel are present in comet comas throughout the solar system, even those on its outer edges. A separate study by Polish astrophysicists, who also used ESO data, reported nickel vapors are also present in the icy interstellar comet 2I / Borisov. This is the first time that heavy metals, usually associated with a hot environment, have been found in the cold coma of distant comets.
Astronomers know that heavy metals exist in the dusty and rocky bowels of comets. But, since solid metals do not usually gaseous at low temperatures, scientists did not expect to find them in the coma of cold comets that are very far from the Sun. Pairs of nickel and iron have been found even in comets observed at a distance of more than 480 million kilometers from the star. This is three times the distance from the Earth to the Sun.
Belgian scientists have found roughly equal amounts of iron and nickel in cometary atmospheres. Material in our solar system, such as those found in the sun and in meteorites, typically contains about ten times more iron than nickel.
Heavy metals are also present in the coma of the interstellar comet 2I/Borisov. Polish scientists observed this object with the X-shooter spectrograph on the VLT ESO. They found that the 2I/Borisov cold coma contains nickel gas.