Rosetta blog: An refurbish on Comet 67P/C-G’s water-ice cycle

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ESA VIRTIS infoLast week we reported on a daily water-ice cycle of Comet 67P/Churyumov-Gerasimenko that was celebrated in a specific segment of a comet’s neck by Rosetta’s VIRTIS instrument, in Sep 2014.

Yesterday at a European Planetary Science Congress, animations were shown covering a duration 1 Aug 2014 to 10 Feb 2015 for dual opposite areas of a nucleus, display a poise of a water-ice over a most longer period.

“We are now means to uncover that this cycle is common in several regions of a nucleus, depending on a enlightenment conditions, and hence serve denote that a due cycle is a ubiquitous resource of H2O ride from abyss to a aspect behaving on comets,” pronounced Fabrizio Capaccioni, VIRTIS principal investigator. Fabrizio described a formula in a press lecture hold during EPSC yesterday afternoon.

The dual cinema are formed on data acquired between 1 Aug 2014, when a comet was during a stretch of about 542 million km (3.62 AU) from a Sun and 10 Feb 2015, when a comet was 352 million km (2.35 AU) from a Sun. They uncover a ice abundance at any time during the comet’s 12.4 hour day for dual opposite regions: one focused on a Imhotep segment on a comet’s vast lobe, a other around a comet’s neck. For any timestamp, any information prove represents a average, for a sold hour of a comet day, over the whole timeframe August-February.

The blue regions prove a participation of ice in a uppermost aspect layer, red shows no ice, and grey indicates portions of a comet that were in shadow.

“We see that in many areas on a comet’s aspect a bluer regions have a brief lifetime, appearing only after emergence and disintegrating a few hours later,” says Fabrizio. “This indicates that in these areas a ice is not fast during a aspect though is deposited during a night and sublimates divided during a day. This is a transparent acknowledgment of a due water-ice cycle.”

The cinema also uncover areas where a bluish colour is determined via a day, that Fabrizio explains as regions of permanent ice – these will be a theme of a destiny study.

Presentations on a comet’s water-ice cycle will also be given as partial of a Rosetta systematic sessions during EPSC after this week, for example: Temporal variability of 67P/Churyumov-Gerasimenko iota bright properties from VIRTIS-M onboard Rosetta by M. Ciarniello et al.

Browse some-more discussion abstracts here.


Source: Rosetta blog