Category Archives: NASA

comet, Comet Tempel-1, jet Propulsion Laboratory, NASA, planetary science, stardust

The Face of a Comet

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Stardust-NExT Shows us Tempel-1

This view of Comet Tempel-1 was taken at 8:39 PST on February 14 when the comet and the spacecraft were about 200 kilometers apart. Click to enlarge for detail.

Well, the wait is over, folks. The close-up pictures are starting to make their appearance on the mission and NASA web pages.  As a former comet researcher, I find these quite compelling.  All my studies were done on the plasma tail, but the nucleus was always interesting, too. So, here’s one of the images of the comet’s nucleus returned from the mission.

Let’s do what scientists do when they look at these things: take a visual inventory. What leaps out at you?  Craters.  Yep. A lot of cratery-looking formations. Also some bumps and nodules. The nucleus of the comet itself has rounded edges, like a potato. It’s not perfectly spherical, and seems to have some flattish-looking plains at the upper right in this image.

There are some bright areas — I’m guessing they’re reflective material glinting in the sunlight.  Probably uncovered ice, maybe from some areas where material has recently outgassed and left fresh ice on the otherwise greyish surface.

Comet Tempel-1 as seen by the Stardust-NExT spacecraft on 8:39 p.m. (PST) on February 14, 2011. Click to see details.

This comet has been at its closest to the Sun since the last time a spacecraft (the Deep Impact mission) saw it in 2005.  The combination of increased solar radiation and heating has changed the surface ices.  The material underneath is more pristine — unchanged. What scientists want to know is the nature of those changes and the difference between the surface and the below-surface ices.  The pristine ices are likely unchanged from when they first formed in the early solar system, and that makes Tempel-1, and indeed — most comets — treasuries of information about conditions in the early solar system.

Okay, that’s some instant science. What do the experts have to say about these and images we haven’t seen yet?  We’ll find out later today (Tuesday, February 15, 2011) after the team members have had time to study the images.  It should be cool news! Stay tuned! If you want to watch the press conference, keep an eye out here for live streaming coverage of the press conference at NASA Jet Propulsion Laboratory.

NASA, NASA Day of Remembrance

Stars and Remembrance

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A Time to Pause

Remembering NASA's lost astronauts

The last week in January and the first week of February marks three tragedies that befell NASA since its formation: the Apollo 1 fire on January 27, 1967, the breakup of 51L — space shuttle Challenger on January 28, 1986, and the loss of the space shuttle Columbia on February 1, 2003. Each event marked a fatal steppingstone for NASA, and for all those who favor the exploration of space. Each event also marked a turning point and a lesson learned for those who design and build the vehicles that get our astronauts to space.

Just as the U.S. and most other countries salute their fallen military heroes who have made the ultimate sacrifice for what they believe in, and as we all honor those who risk their lives to save others (firefighters, law enforcement, and many others), today we take a moment and pause to remember those who gave their lives for the peaceful pursuit of space exploration.

Today is NASA’s Day of Remembrance for the crews of Apollo 1, Challenger, and Columbia. Take a moment today to pause and think about these people and their families.