Pretty Picture: ISS in the X-band
Posted by Emily Lakdawalla
04-03-2010 8:40 CST
This is from the "Just Plain Cool" department: a picture of the International Space Station taken in microwave radar. The specific radio wavelength involved is the X-band, radio with wavelengths of a few centimeters. (I've noticed some bloggers incorrectly reporting this image as being taken in "X-rays," which is quite a different animal entirely, waaaaay shorter wavelength than visible light and not a very friendly wavelength to be irradiating astronauts with; microwave radar is waaaay longer wavelength than visible light and of no consequence to astronaut health.) For comparison, I'm also posting an image of the ISS taken with a plain old optical camera just a couple of months later.
The main reason I'm posting this picture is because it's a picture of a pretty familiar object -- the Space Station -- in an unfamiliar part of the electromagnetic spectrum. I post images here all the time in wavelengths longer than the human eye can see, and it's tempting to assume that images of the same places will look pretty much the same in visible wavelengths. But the photo above shows how simultaneously familiar and strange a well-known object looks in radar, reminding me that my instincts in interpreting what I see in radar images of places like Titan, Venus, and the Moon may not always be reliable.
A final note about this image -- I first learned about it via DLR's Twitter feed. I'm finding it easier to get news about European missions via Twitter than more traditional means!