Red planet, in black and white
This weekend, the Phoenix Mars craft sent home pictures that suggest it might have landed right on top of an . The images show chunks of a white material that scientists said yesterday may be frozen water that was originally hidden beneath a layer of dust. When the Phoenix鈥檚 thrusters kicked in right before it touched down on Mars, the blast must have blown the dirt away, revealing the ice, they said.
I鈥檒l take their word for it, because while all of these black-and-white pictures are striking, they鈥檙e a little hard to make out. How come the 18-year-old Hubble telescope can capture the heavens in rich color, while the cutting-edge Phoenix lander is stuck taking snapshots in gray scale?
I did some snooping around and found that the scientists want it that way 鈥� for now at least.
These early photos are low-res engineering images. They鈥檙e a first priority for the mission because they are small files and easy to send back to Earth. The black-and-whites allow the NASA team to quickly survey the area and scan the spacecraft for damage.
A few recent snapshots have a touch of red, but they are just colored for effect. The spacecraft鈥檚 camera can take 鈥� half through one infrared filter and half through another color. But this setting is designed for scientific accuracy 鈥� not color accuracy. So the tints and hues are only approximations.
Another batch showed ; these color distortions are to help the NASA team distinguish different types of terrain. NASA says it will always mention any false coloring in the captions of its pictures.
The Phoenix camera can switch among 12 different filters 鈥� each revealing 鈥� and soon will start taking pictures in full color. 鈥淏e patient!鈥� says a NASA team member, writing on the lander鈥檚 .
Another question I had: How do the photos get to Earth? Once captured, the digital image beams 鈥渁t about 15 kilobytes a second via an UHF antenna to two spacecraft orbiting Mars,鈥� reports . 鈥淭he orbiters relay the data to NASA's Deep Space Network antenna arrays in Canberra Australia, Madrid, and in California's Mojave Desert. Raw images are sent to the Jet Propulsion Laboratory and posted to the .鈥�
