A special issue of the journal Astronomy & Astrophysics was published online on Friday, featuring 46 articles based on data collected by Rosetta and Philae in the mission’s first year at Comet 67P/Churyumov-Gerasimenko. Topics covered include the comet’s shape and formation theories, the evolution and nature of its activity, the composition of the coma, and the coma’s interaction with the solar wind.
For a full list of contents, click here.
Many of these papers were published over the past few months, and several were already covered by news articles here on the ESA blog and/or the main ESA web portal; you can find the news items linked from the table of contents by clicking on the ‘press release’ button.
Discussion: 6 comments
Thanks for posting, Emily. These papers are a cornucopia of cometary knowledge.
–Bill
Congratulations to ESA and their Country community on the selection of CubeSats up for Misssion do Didymos Binary.
Have taken the concept up to incredible Levels.
Of note the brillant Meta-ization with ChipSats 🙂
Great! I agree with logan friend, great post! 😀
Very grateful to Jean-Loup Bertaux on allowing open access to his new paper on:
“Estimate of the erosion rate from H2O mass-loss measurements from SWAN/SOHO in previous perihelions of comet 67P/Churyumov-Gerasimenko and connection with observed rotation rate variations”.
“…[argumenting that] monitoring the rotation rate yields a very accurate and precious indicator of the global activity of the comet” 🙂
“At 1 m ± 0.5 m, the erosion rate per orbit is high…”, …average over the whole nucleus…”.
“…while the southern hemisphere, which is fully exposed near perihelion, would experience more than 4 m, reaching 10 m at some places [‘circular features’?]”.
“It is clear that the returned material constitutes the blanket layer of “smooth” material seen in many areas [and gets significantly ‘air-born’ at each perihelion].”
“The thermal skin depth should be about 7 m for comet 67/P”. [Parishioners had established limit at 10m. Good!].
“It is nonetheless quite striking that a modest production rate of 3 kg/s thrown almost vertically can still slow the rotation of a body of 10 billion tons in a measurable amount.”
[Have you considered electro-clutching in the kinetic budget? If well Nano in intensity, nucleus is ‘twisting’ against all of the field structure of the bow (even if not shocked, a field there is) . Maybe that’s why ‘braking’ seems a little early. The field is effect of the average exosphere pressure (and friction) against solar wind, and is a lot more stable than jets’ (outbursts?)kinetic vectors. So the curve is going to be very smooth at start and end].
Marco&Cooper:
“We have considered three potential mechanisms for a change in the rotation rate of the nucleus in two circumstances. The mechanisms are thermal dilatation, progressive separation of the two lobes, and the more classical outgassing-induced torque.”
“…If it is connected with the separation of the two lobes, it will soon be detectable in the refined analysis images, the distance between head and body landmarks should increase more than the distance between landmarks on the same lobe.”
Future is the territory of Scientists:
https://www.esa.int/Our_Activities/Space_Science/Looking_into_our_future_An_interview_with_Jean-Loup_Bertaux
Is_ rotation rate accurate at Jupiter distance? Cold Jupiter could definitely establish ‘electro-clutching’.