New study shows a certain family of comets contain water similar to earth’s water.
New research has found that one family of comets, the hyperactive comets, exhibit the same ratio of deuterium to hydrogen (D/H ratio) as Earth’s water. This was based on data from Comet 46P/Wirtanen analysed using the SOFIA airborne observatory in December 2018. This was the third comet found to exhibit the same D/H ratio as terrestrial water.
Terrestrial deuterium-to-hydrogen ratio in water in hyperactive comets, D. C. Lis, D. Bockelee-Morvan, R. Guesten, N. Biver, J. Stutzki, Y. Delorme, C. Duran, H. Wiesemeyer, Y. Okada. Astronomy & Astrophysics, 20 May 2019. Doi:10.1051/0004-6361/201935554