Using the COmetary Secondary Ion Mass Analyser (COSIMA) instrument on board ESA’s Rosetta spacecraft, researchers have detected phosphorus and fluorine in solid particles collected from the inner coma of comet 67P/Churyumov-Gerasimenko.
This false-color image of 67P/Churyumov-Gerasimenko was taken by the Rosetta navigation camera on 15 June 2015 from a distance of 207 km from the comet center. Image credit: ESA / Rosetta / NAVCAM / CC BY-SA IGO 3.0.
Comets are remnants from the protoplanetary disk around the young Sun.
Being formed beyond the ice-line orbiting the Sun, on average, at distances further than the asteroid belt, and experiencing less processing, they are thought to represent the most pristine matter of the Solar System.
The first detection of phosphorus in a comet was made in 1986 in the spectra from cometary dust collected during flyby of comet 1P/Halley by NASA’s Vega 1 mission.
It was also detected in dust particles collected by NASA’s Stardust spacecraft during the flyby of comet 81P/Wild in 2004, and returned to Earth in 2006.
“Another detection of phosphorus and fluorine came from the ROSINA instrument on board Rosetta,” said co-lead author Dr. Harry Lehto from the Department of Physics and Astronomy at the University of Turku and his colleagues.
“In that case, elemental phosphorus, phosphorus monoxide (PO) and carbon monofluoride (CF) were detected in the gas phase of 67P/Churyumov-Gerasimenko.”
“We report here the detection phosphorus and fluorine in mass spectra measured from solid dust particles of this comet.”
For the study, the scientists analyzed a set of spectra from 24 solid particles collected by the COSIMA instrument in the vicinity of 67P/Churyumov-Gerasimenko.
They found phosphorus P+ ions and CF+ secondary ions originating from the cometary dust.
“We have shown that apatite minerals are not the source of phosphorus, which implies that the discovered phosphorus occurs in some more reduced and possibly more soluble form,” Dr. Lehto said.
“This result completes the detection of life-necessary CHNOPS-elements in solid cometary matter, indicating cometary delivery as a potential source of these elements to the young Earth.”
A paper on the findings was published in the Monthly Notices of the Royal Astronomical Society.
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Esko Gardner et al. 2020. The detection of solid phosphorus and fluorine in the dust from the coma of comet 67P/Churyumov-Gerasimenko. MNRAS 499 (2): 1870-1873; doi: 10.1093/mnras/staa2950
