The Viking 1 space probe settled into orbit around Mars in 1976, dropping a surface lander in the process. The probe stayed in orbit to monitor the planet, returning thousands of pictures from millions of kilometers away.
Those pictures are sitting in an archive, and sometimes have hidden jewels in them. As Emily Lakdawalla reports, somehow the keen-eyed Daniel Macháček spotted an amazing thing: the shadow of the Martian moon Phobos passing over a dust storm:
Wow! This animation is sped up by a factor of 10, and you can see the tiny moon’s shadow slip across the face of the planet. He also has one sped up 40X, and there you can see the slow movement of the dust storm, too… though it’s only slow due to distance; I’m sure someone standing on the surface would laugh ruefully at describing the 100 km/hr gusts as "slow". If they could breathe, that is.
Anyway, Emily has more information on the animations. I think this is amazing work, and we’ll be seeing more things like this as the planetary (and astronomical) databases get plumbed by the public. A lot of folks out there are very talented at digging out treasures, and equally adept at creating beautiful imagery and animations, too.
[Note: At the bottom of this post is a gallery of amazing NASA satellite images of the Earth!]
I need to make a list of the stuff I love about science, because I keep coming up with more. This time, it’s how surprising the Earth can be, even though we live on the dang thing.
For example, when I think of dust storms, I think of China and the Sahara or maybe the Dust Bowl in the U.S. I certainly don’t think of Alaska! But then, NASA’s Terra satellite set me straight:
[Click to 49thstatenate.]
Check that out! An actual series of dust storms blowing off the coats of Alaska! The cause was obvious in retrospect: as billions of tons of glacier flow languidly across the landscape, they crush the rocks underneath into powder called — get this — glacial flour. This gets deposited as mud underneath the glacier. When the glacier recedes a bit, the mud dries, and the wind can blow it away.
Tadaa! Dust storms off the coast of Alaska. Maybe Marian knows all about these, but for me, that’s a first.
The stuff I learn from NASA. Man.
Here are some other amazing images of the Earth from space! Use the thumbnails and arrows to browse, and click on the images to go through to blog posts with more details and descriptions.