Comet jet in 3D

OSIRIS scientists have created a spectacular anaglyph view of a jet seen blasting from the nucleus of Comet 67P/Churyumov-Gerasimenko in August. Rosetta observed increased levels of cometary activity in the weeks around perihelion as the comet made its closest approach to the Sun along its orbit, at a distance of about 186 million km – between the orbits of Earth and Mars. On the approach, the increasing solar radiation heated up the comet’s nucleus, causing its frozen ices to escape as gas and stream out into space at an ever-greater rate, dragging the comet’s dust with it. A period of peak of activity, where distinct jets increase in number and intensity, is thus expected in the weeks around perihelion. The jet shown here is one such example of the high level of activity seen over the last months; it was witnessed on 12 August, just one day before perihelion. But creating a 3d anaglyph of dynamic events like this is notoriously difficult: often the jets are too faint or their duration is too short to find two high-quality images taken several minutes apart that are suitable to pair together to create this type of view. However, the OSIRIS team got lucky with this particular event, capturing two images separated by about two-and-a-half minutes. The image shows a bright, collimated jet embedded in a broader emission structure. The three dimensional perspective also reveals the conical shape of the jet and that the collimated feature is emitted towards the observer. Jets have been seen to originate from a large diversity of morphological features on the comet’s surface, such as pits, cliffs or icy boulder fields. The physical processes responsible for the different jet structures are subject to much discussion, but anaglyphs like these can certainly help in gaining an understanding of their […]

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