mercredi 1 avril 2015

Rosetta - 14 km flyby












ESA - Rosetta Mission patch.

April 1, 2015

As part of the recent series of trajectories around Comet 67P/C-G, Rosetta passed within about 14 km of the comet’s surface on Saturday. Despite operational difficulties encountered during the flyby, Rosetta’s NAVCAM was able to acquire images on the way in to and shortly after closest approach.
 
Comet on 28 March 2015 – NavCam mosaic

Image above: This stunning scene was created from two NAVCAM frames acquired at 19.9 km from the comet centre on 28 March. The scale is about 1.7 m/pixel and the image measures 3.1 x 1.7 km. The image has been adjusted for intensity and contrast, and the vignetting has been fixed. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.

The approach images were acquired between 09:33 and 09:51 UT, and show an oblique view across the Imhotep region. This provides the focus for the two-image mosaic presented above, which has been cropped and rotated to highlight the impressive scenery.

Focusing on the 2x2 montage in its original orientation (below), the scene captures the boundary between Imhotep and Ash to the left. The cliffs of Hathor on the small lobe are visible in the background at the far left. Note that the top-right frame also includes the region that was imaged during the 14 February flyby at 6 km.

Comet on 28 March 2015 – NavCam montage (a)

Images above: Four image montage of images taken by Rosetta’s NAVCAM from an average distance of 20.2 km from the comet centre. The scale at this distance is 1.7 m/pixel and the size of each 1024 x 1024 pixel frame is 1.8 km. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.

The second set of images, presented below, was acquired between 14:35 and 14:53 UT, not long after the closest approach at 13:04 UT.

Comet on 28 March 2015 – NavCam montage (b)

Images above: Four image montage of images taken by Rosetta’s NAVCAM from an average distance of 16.6 km from the comet centre. The scale at this distance is 1.4 m/pixel and the size of each 1024 x 1024 pixel frame is 1.4 km. Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0.

In this orientation the large lobe is to the left and the small lobe to the right. The top right frame offers a particularly stunning view onto Hapi, the comet’s ‘neck’ region that is littered with boulders. This view also provides a good look at the many interesting, curved markings visible on the smooth surface.

In the same frame, further details in the cliffs of Hathor can be seen, leading up to the ‘head’ of the comet’s small lobe. The smooth region towards the right of this frame shows the transition between this smooth, presumably dust-covered portion, and the layered, exposed cliffs below.

More about Rosetta:

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was provided by a consortium led by DLR, MPS, CNES and ASI. Rosetta is the first mission in history to rendezvous with a comet. It is escorting the comet as they orbit the Sun together. Philae landed on the comet on 12 November 2014. Comets are time capsules containing primitive material left over from the epoch when the Sun and its planets formed. By studying the gas, dust and structure of the nucleus and organic materials associated with the comet, via both remote and in situ observations, the Rosetta mission should become the key to unlocking the history and evolution of our Solar System.

For more information about Rosetta mission, visit: http://www.esa.int/Our_Activities/Space_Science/Rosetta

Images (mentioned), Text, Credit: European Space Agency (ESA).

Best regards, Orbiter.ch