|
|
The Planetary Society Blog
By Emily Lakdawalla
HiRISE targets the Beagle 2 landing ellipse
Feb. 14, 2007 | 14:55 PST | 22:55 UTC
A while ago I wrote about a site where the Beagle 2 team thinks their spacecraft crashed. It was a tiny, dark spot (about 20 meters in diameter) visible in Mars Global Surveyor MOC images on the flank of a large crater (a little under 2 kilometers in diameter). The MOC team had already dismissed the spot as a possible Beagle 2 crash site, having determined that it was a small, eroded impact crater, but the Beagle 2 team published an analysis indicating what they thought were parts of their spacecraft, including its deployed airbags.
Well, HiRISE has now taken a look at the site, and it doesn't look like Beagle 2 is in there. Here is a montage of the two MOC images of the site with the new HiRISE picture. The one on the left is the initial image that was thought to be a splotch caused by the Beagle 2 crash; the center one is the one interpreted by the MOC team to prove that the spot was not a crash site, but was instead a small, eroded impact crater; and the one on the right is the HiRISE image, which indeed shows a small, eroded impact crater with no obvious sign of spacecraft hardware. Three views of the putative impact site of Beagle 2
These three images are of a 20-meter-diameter crater that the Beagle 2 team thought may have contained the landing (or crash) site of their small lander. The first two images were taken by MOC in 2003 and 2004, with native resolutions of 1.5 (left) and 0.5 (center) meters per pixel. They are enlarged here to match the resolution of the HiRISE view, 0.25 meters per pixel (right). Credit: NASA / JPL / MSSS / U. Arizona |
Beagle 2 was a very small spacecraft, so it is a little hard to be certain that there are no parts of it in this image, especially since it's been three years since the landing, time enough for some transient markings of a crash to have been blown away. It will be especially hard to find if the parachute never deployed. Not only would the parachute be the easiest piece of Beagle 2's hardware to spot, but if it didn't deploy then it wouldn't have slowed Beagle 2's descent, so the spacecraft could have landed considerably downrange of where people are looking for it.
So now the question is: where is Beagle 2? The HiRISE team released two large images of the area today. One of them, PSP_002347_1915, crosses the landing ellipse, while one, PSP_002136_1920, is located just outside it. The image releases did not include any triumphant shouts of discovery of Beagle 2 wreckage, which must mean that they looked but couldn't find anything suggestive. It's still worth a search, though. Here's a context view showing the locations of the two images (thanks to Doug Ellison for figuring out where that second one was located -- I couldn't find it myself):Context map for HiRISE images of Beagle 2 landing siteThis map of the Beagle 2 landing ellipse is composed of images from Mars Odyssey THEMIS (base map), higher-resolution views from Mars Global Surveyor MOC, and two strips from Mars Reconnaissance Orbiter HiRISE. MOC imaging after Beagle 2 was lost was focused on the eastern half of the ellipse, because atmospheric conditions on Mars likely resulted in the spacecraft landing downrange of the targeted spot. HiRISE image PSP_002347_1915 overlaps a large crater, on the flank of which the Beagle 2 team identified a possible crash site for the spacecraft. Credit: NASA / JPL / MSSS / U. Arizona / Doug Ellison |
Like all HiRISE images, these are huge files. 2347_1915 is 813 Megabytes and 2136_1920 weighs in at 452 megs. Most of you probably can't recreationally download these. I have downloaded them, but haven't had the time to do an exhaustive search yet. Just for fun, I chopped up the part of 2347_1915 that overlaps the landing ellipse into twelve pieces of 40 Megabytes or smaller apiece and saved them in lossless PNG format; you can download them if you would like to have a look around yourself. Here's a map key and links to each of the pieces.HiRISE image overlapping the Beagle 2 landing ellipseThis portion of Mars Reconnaissance Orbiter HiRISE release 2347_1915 overlaps the Beagle 2 landing ellipse. It covers an area 6.25 kilometers wide by 8 kilometers tall at a resolution of 25 centimeters per pixel. The map shown here is downsampled to 10 meters per pixel. Each of the squares can be downloaded at their full resolution through the links below.
Top row, left (35 MB) Top row, center (39 MB) Top row, right (20 MB) Second row, left (32 MB) Second row, center (41 MB) Second row, right (25 MB) Third row, left (27 MB) Third row, center (40 MB) Third row, right (30 MB) Bottom row, left (22 MB) Bottom row, center (37 MB) Bottom row, right (32 MB) Credit: NASA / JPL / U. Arizona |
Here are some simulations of what the Beagle 2 hardware might look like to HiRISE, courtesy, as usual, of Doug Ellison.Simulated views of the Beagle 2 hardware from HiRISE
These simulations show what the Beagle 2 hardware might look like on the Martian surface to the HiRISE camera on Mars Reconnaissance Orbiter. Beagle 2 was never heard from after being released by Mars Express toward the surface of Mars on December 19, 2003. It is not known whether its parachute or airbags deployed correctly, or if the whole spacecraft struck the ground to form a small impact crater. Credit: Doug Ellison |
I invite everyone with the patience to download these images and have a look around to see what you can find. The search will, no doubt, continue for Beagle 2. I'm not sure that HiRISE will actively be targeting the area for the purpose of continuing the search, but there will likely be more images in Isidis Planitia from time to time, and who knows? One of them may contain the missing spacecraft.
By the way, I thought I should mention a JPL press release from last week indicating some problems with noise in HiRISE's detectors. Some media reports have pretty alarming things to say about the condition of the camera, but the situation is not as bad as the reports state, and HiRISE imaging is continuing apace. HiRISE has 14 detectors, each of which has two channels. One of the channels on one of the infrared detectors has had a significant problem with bad pixels since shortly after launch. The same problem began to show up in November in another of the channels on a different detector, and recently it has begun to crop up in five more. This is certainly a significant concern, but the camera team is now developing workarounds that, if they won't fix the problem, will hopefully slow its development. I asked the HiRISE principal investigator Alfred McEwen to comment on the status of their work on the noise problem, and he said, "Were getting fantastically beautiful images every day with no signs of problems except in the one infrared channel that has been especially bad since launch. That's because we're using a longer warmup time before each image. So for now everything is great, but we still have concerns about the long-term performance." Alfred has stated elsewhere that he believes the camera will last through the nominal mission but is concerned that these issues might affect the camera's usability over a longer period than that.
|
|
[ what is this? ]