Category Archives: Asteroids & Comets

Asteroids & Comets, Space Science

Rosetta prepares for deployment of lander on Nov. 12th

 The European Space Agency’s Rosetta spacecraft now orbiting the Comet 67P/Churyumov–Gerasimenko will release  its Philae lander to touch down on the comet on November 12th at 08:35 UTC (09:35 CET, 03:35 EST) . They have now chosen the name Agilkia for the landing spot: Farewell ‘J’, hello Agilkia – ESA

Rosetta & Philae at comet 67P. Credit: ESA–C. Carreau/ATG medialabRosetta & Philae at comet 67P. Credit: ESA–C. Carreau/ATG medialab

On October 31st, Rosetta made a maneuver to align itself for the release of the lander :  Rosetta lined up for lander delivery – Rosetta blog.

the next planed orbit-changing manoeuvres will occur on the 12th at (a) 2 hours before separation and (b) about 40 minutes after (see animation below), in between which Philae will be released.

The pre-delivery manoeuvre will shift Rosetta’s trajectory so that the orbiter would be on a path so as to pass over the comet at a distance of 5 km, while the separation will occur at 08:35 UTC on board the spacecraft about 22 km (the confirmation signal will arrive on Earth at 09:03 UTC).

The second manoeuvre will cause a deflection of the Rosetta trajectory away from the comet; it will occur 40 minutes after separation, and help guarantee visibility of Philae at touchdown.

This video shows the orbital path (accelerated in time) of the orbiter

This video is about the landing and the people involved in the project:

Asteroids & Comets, Multiple media, Space Science

Latest Rosetta images

The Rosetta spacecraft continues to take amazing photos of comet  67P/C-G as it gets closer and closer to it. Check out these image galleries:

Here are three recent images:

ESA_Rosetta_NAVCAM_141026_mosaic-922x1024[1]

 

Four-image mosaic comprising images taken by Rosetta’s navigation camera from a distance of 9.8 km from the centre of comet 67P/C-G – about 7.8 km from the surface. The corresponding image scale is about 66 cm/pixel, and the mosaic covers roughly 1200 x 1350 metres.

The individual image frames and more information is available via the blog: CometWatch – 26 October

 

Comet_on_24_October_NavCam_node_full_image_2[1]

 

Four-image montage comprises images taken by Rosetta’s navigation camera from a distance of 9.8 km from the centre of comet 67P/C-G – about 7.8 km from the surface. The corresponding image scale is about 66 cm/pixel, so each 1024 x 1024 pixel frame is about 676 m across. In this orientation the larger lobe occupies the upper frames, with the neck filling the lower frames. The smaller lobe of the comet is out of view towards the right.

The individual image frames and more information is available via the blog: CometWatch – 24 October

Comet_activity_10_September_2014_node_full_image_2[1]

 

Rosetta OSIRIS wide-angle camera image of Comet 67P/Churyumov-Gerasimenko on 10 September 2014, showing jets of cometary activity along almost the entire body of the comet.

 

Asteroids & Comets, SpaceCasts

Video: Siding Spring and other comet-planet encounters

A SETI Institute discussion of the Comet Siding Springs fly-by of Mars and other comet encounters:

Asteroids & Comets, Space films and videos

Video: ‘Ambition’ a sci-fi short film

A very impressive short film in tribute to ESA’s Rosetta mission to 67P/Churyumov-Gerasimenko: Rosetta: the ambition to turn science fiction into science fact  – ESA

Ambition is a collaboration between Platige Image and ESA. Directed by Tomek Bagiński and starring Aiden Gillen and Aisling Franciosi, Ambition was shot on location in Iceland, and screened on 24 October 2014 during the British Film Institute’s celebration of Sci-Fi: Days of Fear and Wonder, at the Southbank, London.

Here’s a video about the making of Ambition:

Asteroids & Comets, Astronomy, Mars

Comet Siding Spring flew by Mars and watched by orbiters and rovers

The orbiters circling Mars survived the fly-by of Comet Siding Spring last Sunday just fine. The NASA JPL site Comets: Siding Spring (C/2013 A1) has lots of images and reports about the event. For example,

NASA Rover Opportunity Views Comet Near Mars

Mars Rover Opportunity's View of Passing CometMars Rover Opportunity’s View of Passing Comet

Researchers used the panoramic camera (Pancam) on NASA’s Mars Exploration Rover Opportunity to capture this view of comet C/2013 A1 Siding Spring as it passed near Mars on Oct. 19, 2014. Credit: NASA/JPL-Caltech/Cornell Univ./ASU/TAMU

NASA’s Mars Exploration Rover Opportunity captured images of a comet passing much closer to Mars than any previous known comet flyby of Earth or Mars. The images of comet Siding Spring were taken against a backdrop of the pre-dawn Martian sky on Sunday (Oct. 19).

Images of comet A1 Siding Spring from the rover’s panoramic camera (Pancam) are online at:

Researchers used Opportunity’s Pancam to image at a range of exposure times about two-and-one-half hours before the closest approach of the nucleus of comet Siding Spring to Mars. By the time of closest approach at about 87,000 miles (139,500 kilometers), dawn had lit the sky above Opportunity.

“It’s excitingly fortunate that this comet came so close to Mars to give us a chance to study it with the instruments we’re using to study Mars,” said Opportunity science team member Mark Lemmon of Texas A&M University, who coordinated the camera pointing. “The views from Mars rovers, in particular, give us a human perspective, because they are about as sensitive to light as our eyes would be.”

Three NASA Mars orbiters, two Mars rovers and other assets on Earth and in space are studying comet Siding Spring. This comet is making its first visit this close to the sun from the outer solar system’s Oort Cloud, so the concerted campaign of observations may yield fresh clues to our solar system’s earliest days more than 4 billion years ago.

Opportunity has been roving on Mars since January 2004 and has provided evidence about the Red Planet’s ancient wet environments.

For more about Opportunity, visit:

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The Mars Reconnaissance Orbiter capture images of the comet as well:

Mars Orbiter Image Shows Comet Nucleus is Small

First Resolved Image of a Long-Period Comet's Nucleus

First Resolved Image of a Long-Period Comet’s Nucleus

These images were taken of comet C/2013 A1 Siding Spring by NASA’s Mars Reconnaissance Orbiter on Oct. 19, 2014, during the comet’s close flyby of Mars and the spacecraft. Credit: NASA/JPL-Caltech/University of Arizona

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter captured views of comet C/2013 A1 Siding Spring while that visitor sped past Mars on Sunday (Oct. 19), yielding information about its nucleus.

The images are the highest-resolution views ever acquired of a comet coming from the Oort Cloud at the fringes of the solar system. Other spacecraft have approached and studied comets with shorter orbits. This comet’s flyby of Mars provided spacecraft at the Red Planet an opportunity to investigate from close range.

Images of comet Siding Spring from HiRISE are online at: http://mars.nasa.gov/multimedia/images/?ImageID=6682

The highest-resolution of images of the comet’s nucleus, taken from a distance of about 86,000 miles (138,000 kilometers), have a scale of about 150 yards (138 meters) per pixel. Telescopic observers had modeled the size of the nucleus as about half a mile, or one kilometer wide. However, the best HiRISE images show only two to three pixels across the brightest feature, probably the nucleus, suggesting a size smaller than half that estimate.

For more about HiRISE, visit: http://hirise.lpl.arizona.edu

For more about Mars Reconnaissance Orbiter, visit: http://mars.nasa.gov/mro/

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NASA released a composite image showing the comet and the Red Planet together without under or over-exposing either:

Close Encounters: Comet Siding Spring Seen Next to Mars

comet_springs_0[1]

This composite NASA Hubble Space Telescope Image captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet, which happened at 2:28 p.m. EDT October 19, 2014. [Larger image]

This composite NASA Hubble Space Telescope Image captures the positions of comet Siding Spring and Mars in a never-before-seen close passage of a comet by the Red Planet, which happened at 2:28 p.m. EDT October 19, 2014. The comet passed by Mars at approximately 87,000 miles (about one-third of the distance between Earth and the Moon). At that time, the comet and Mars were approximately 149 million miles from Earth.

The comet image shown here is a composite of Hubble exposures taken between Oct. 18, 8:06 a.m. EDT to Oct. 19, 11:17 p.m. EDT. Hubble took a separate photograph of Mars at 10:37 p.m. EDT on Oct. 18.

The Mars and comet images have been added together to create a single picture to illustrate the angular separation, or distance, between the comet and Mars at closest approach. The separation is approximately 1.5 arc minutes, or one-twentieth of the angular diameter of the full Moon. The background starfield in this composite image is synthesized from ground-based telescope data provided by the Palomar Digital Sky Survey, which has been reprocessed to approximate Hubble’s resolution. The solid icy comet nucleus is too small to be resolved in the Hubble picture. The comet’s bright coma, a diffuse cloud of dust enshrouding the nucleus, and a dusty tail, are clearly visible.

This is a composite image because a single exposure of the stellar background, comet Siding Spring, and Mars would be problematic. Mars is actually 10,000 times brighter than the comet, and so could not be properly exposed to show detail in the Red Planet. The comet and Mars were also moving with respect to each other and so could not be imaged simultaneously in one exposure without one of the objects being motion blurred. Hubble had to be programmed to track on the comet and Mars separately in two different observations.

The images were taken with Hubble’s Wide Field Camera 3.