When NASA's Phoenix lander touches down on Mars Sunday, it will be carrying two special tools to give scientists their best look at the Red Planet's true colors.
They're called color-calibration targets and are about the size of hockey pucks. Each device is covered with color chips, designed by University of Central Florida Physics and Astronomy Professor Dan Britt and two students. When Phoenix's camera takes pictures of the terrain, it will also capture the calibration targets, allowing scientists to compare the colors in each photo and determine the actual hues.
Knowing the true colors allows spectroscopists, such as Britt, to determine what makes up the planet's terrain. The colors are one reason NASA says that liquid water once existed on Mars, and they help geologists analyze layers of rock deposited over thousands of years.
"Mars is a dusty place with a harsh climate," said Britt, who has worked on calibration targets for four other Mars missions. Over time, dust covered the previous targets and color chips, making it nearly impossible to decipher accurate hues.
So, for the first time, calibration targets on the Phoenix Mars have built-in magnets to repel the dust. Each magnet is about 100 times stronger than a refrigerator magnet and should keep the targets "clean" while the lander samples soils in the Martian arctic region.
While Britt created the color chips, the targets and magnets were designed by scientists from the University of Copenhagen in Denmark.
The lander is expected to reach its destination May 25, after a 422-million mile trip since its launching last August. Besides Britt's targets and a camera, Phoenix is equipped with a robotic arm that scientists hope will scoop up water ice thought to be just under Mars' surface.
With past color-calibration targets, Britt and his team -- which has included a University of Florida professor and UCF students -- have helped scientists learn more about Mars' surface, which Britt says is actually yellowish-brown and not red.
Britt started creating the color chips for Phoenix about three years ago in his lab at UCF. Made of rubbery silicon and paint pigments, the color chips were embedded in an aluminum casting and tested under extreme conditions -- intense ultraviolet light and depressurization -- before they left Earth last year.
Also new on several of the Phoenix lander's color targets is a special metal-infused coating created by Britt and UF chemistry professor Randolph S. Duran. The coating also should help keep away the dust, Britt says.
About a decade ago, Britt served as project manager and Deputy Imaging Team leader for the camera on NASA's Mars Pathfinder. He also participated in NASA's Deep Space One mission to encounter comet 19P/Borrelly in 2001. Now, he's working on fluorescent colored chips for future calibration targets for the Mars Science Laboratory rover, scheduled to launch in fall 2009. They're expected to help scientists capture infrared photos of the terrain for future analysis of the mysterious, so-called "Red Planet."
"We're doing this work to support future missions," he said. "It's always fun to build things that end up on other planets."