Rosetta data discoveries to guide future comet missions
EU-funded researchers have gleaned important insights into the composition, topography and activity of a comet, helping scientists prepare for the next close encounter with these icy, dusty remnants from the formation of the solar system.
© Yuriy Mazur #71824509 2019, source:stock.adobe.com
Updated on 26 August 2019
The EU-funded MIARD project studied data from the European Space Agencys Rosetta mission, which made history in 2014 when it landed the Philae probe on the surface of comet 67P/Churyumov-Gerasimenko. The mission resulted in remarkable discoveries, including detecting ancient icy water substantially different to water on Earth and identifying a pungent chemical composition of hydrogen sulphide, ammonia and formaldehyde gassing out from the comets porous structure, providing insights into the early days of the solar system.
By delving deeper into the reams of data generated during the mission, the MIARD team has produced detailed models of 67P/Churyumov-Gerasimenkos gas and dust dynamics, a study of gas flow through the comets porous near-surface layers, and 3D maps of the nucleus that divide the surface into 70 subregions, as well as more accurate information about the comets orbital motion and rotation.
We spent a lot of time being careful and improving the analysis of data from the Rosetta mission by combining data sets from several instruments. There is a tendency for people to publish quickly when missions arrive at a new target, but this can lead to conclusions that are superficial or even occasionally wrong, explains MIARD coordinator Nicolas Thomas, professor of experimental physics at the University of Bern in Switzerland.
One thing that was particularly amusing was that we found ESAs knowledge of the spacecraft position and therefore the comets position was not accurate. We are now working with ESA to improve this situation and get the position better defined, he says.
Knowledge gained in MIARD, such as details about the tensile strength of the comets nucleus material and the effects of thermal fracturing on the evolution of its surface will help guide future space exploration missions, including a possible return voyage by ESA to 67P/Churyumov-Gerasimenko and visits to similar solar system bodies.
We saw very clearly the importance of understanding why comets are active, and we can now see what the next mission to a comet needs to do. For example, the link between ices and non-volatile material in the nucleus is a key question we should try to answer in the next 10 to 20 years, Thomas concludes.