Life predominantly occurs in the form of ammonium salts in comet, More than 30 years ago, Joto’s European comet mission passed Halley’s comet. An important finding from measurements with this instrument is that the Halley coma appears to be deficient in nitrogen, a foggy layer of comets that forms when the comet passes near the sun.
Although nitrogen (N) is detected in the form of ammonia (NH3) and hydroxyic acid (HCN), the frequency is far from the expected cosmic frequency.
More than 30 years later, researchers solved this puzzle thanks to a happy incident.
Less than a month before the end of the Rosetta mission, the spacecraft was only 1.9 km above the surface of Churi as it flew through dusty comet clouds and the form of ammonium salts in comet.
By flying through dust clouds, substances can be detected which usually remain in particles in a cold comet environment and hence cannot be measured. The number of particles, some of which have never been measured on a comet, is amazing. In particular, the frequency of ammonia, a combination of nitrogen and hydrogen from the NH3 formula, is suddenly many times higher.
As a salt, ammonia has a much higher evaporation temperature than ice and is therefore usually present as a solid in comet cold environments. So far it has not been possible to measure this solid by remote observation with a telescope or in situ.
Extensive laboratory work is needed to demonstrate the presence of these salts in comic ice cream.
The team found traces of five different ammonium salts: ammonium chloride, ammonium cyanide, ammonium cyanate, ammonium formate and ammonium acetate. At present, the absence of nitrogen in comets has become a mystery. Ammonium salts found contain several astrobiologically relevant molecules that can lead to the development of urea, amino acids, adenine, and nucleotides. This is clearly an additional indication that the influence of comets is related to the appearance of life on Earth.