Stardust Finds Human-made Scar on Comet Tempel 1
This pair of images shows the before-and-after comparison of the part of comet Tempel 1 that was hit by the impactor from NASA's Deep Impact spacecraft. Image credit: NASA/JPL-Caltech/University of Maryland/Cornell
NASA’s Stardust spacecraft returned new images of a comet showing a scar resulting from the 2005 Deep Impact mission. The images also showed the comet has a fragile and weak nucleus.
The spacecraft made its closest approach to comet Tempel 1 on Monday, Feb. 14, at 8:40 p.m. PST (11:40 p.m. EST) at a distance of approximately 178 kilometers (111 miles). Stardust took 72 high-resolution images of the comet. It also accumulated 468 kilobytes of data about the dust in its coma, the cloud that is a comet’s atmosphere. The craft is on its second mission of exploration called Stardust-NExT, having completed its prime mission collecting cometary particles and returning them to Earth in 2006.
The Stardust-NExT mission met its goals, which included observing surface features that changed in areas previously seen during the 2005 Deep Impact mission; imaging new terrain; and viewing the crater generated when the 2005 mission propelled an impactor at the comet.
“This mission is 100 percent successful,” said Joe Veverka, Stardust-NExT principal investigator of Cornell University, Ithaca, N.Y. “We saw a lot of new things that we didn’t expect, and we’ll be working hard to figure out what Tempel 1 is trying to tell us.”
Several of the images provide tantalizing clues to the result of the Deep Impact mission’s collision with Tempel 1. “We see a crater with a small mound in the center, and it appears that some of the ejecta went up and came right back down,” said Pete Schultz of Brown University, Providence, R.I. “This tells us this cometary nucleus is fragile and weak based on how subdued the crater is we see today.”
Engineering telemetry downlinked after closest approach indicates the spacecraft flew through waves of disintegrating cometary particles, including a dozen impacts that penetrated more than one layer of its protective shielding.
“The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II,” said Don Brownlee, Stardust-NExT co-investigator from the University of Washington in Seattle. “Instead of having a little stream of uniform particles coming out, they apparently came out in chunks and crumbled.”
While the Valentine’s Day night encounter of Tempel 1 is complete, the spacecraft will continue to look at its latest cometary obsession from afar.
“This spacecraft has logged over 3.5 billion miles since launch, and while its last close encounter is complete, its mission of discovery is not,” said Tim Larson, Stardust-NExT project manager at JPL. “We’ll continue imaging the comet as long as the science team can gain useful information, and then Stardust will get its well-deserved rest.”
Stardust-NExT is a low-cost mission that is expanding the investigation of comet Tempel 1 initiated by the Deep Impact spacecraft. The mission is managed by JPL for NASA’s Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft and manages day-to-day mission operations.
The latest Stardust-Next/Tempel 1 images are online at: https://www.nasa.gov/mission_pages/stardust/multimedia/gallery-index.html.
More information about Stardust-NExT is at: https://stardustnext.jpl.nasa.gov.
One response to “Stardust Finds Human-made Scar on Comet Tempel 1”
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WOWEE, TOTALLY AWESOME!!! Boy, talk about the perfect Valentine’s Day gift to the space-fan community, one that’s completely out of this world! It really gave me great joy to finally be able to see the rest of the comet (not visible to Deep Impact) — AND, the crater — which turns out to be not round; but sort of polygonal, and very subtle. And yes, there is a central mound, too. For all you people who used to wonder “What does a cometary nucleus REALLY LOOK LIKE?” Well, we now have close-up images of five such objects; and they are blacker than coal dust! At least, such is the case with all of these — except for a few very minor color variations (very slight, neutral brown overtones in the case of Tempel 1).
Stardust NExT, while not the first spacecraft to explore two comets (it’s EPOXI that carries THAT distinction), it DOES have two firsts of its own: returning samples of a comet back to Earth (from Wild 2 on January 15 of 2006, two years after its encounter there); and, making a follow-up observation of a comet (Tempel 1) — in order to see what the Deep Impact crater looks like, to map the rest of the comet, and to look for erosional changes that have taken place during the intervening 5-1/2 years. The spacecraft is now being decommissioned, as it only has a tiny handful of fuel left — not nearly enough for a third encounter!
Fare thee well, Stardust; you were good to the last drop!
o:-)