NASA has released the first processed images from the high-resolution telescopic camera aboard its Mars Reconnaissance Orbiter, which arrived at the Red Planet less than a month ago.
The latest views from the High Resolution Imaging Science Experiment, or HiRISE, follow up on a preliminary release of a single black-and-white image on March 24. The probe went into Martian orbit on March 10, took a series of eight test pictures, then went into a months-long aerobraking phase to adjust its orbit for full-scale science operations.
The processed versions of the test pictures — which can stretch up to 20,000 pixels wide and 60,000 pixels long — were released on Thursday and Friday. The HiRISE team will use these images to fine-tune their processing techniques before the start of the primary science mission this fall.
The pictures show that both the orbiter and the HiRISE camera are working extremely well, according to imaging team leader Alfred McEwen of the University of Arizona.
"The images are wonderful," McEwen said in a status report from the university. "We're learning a great deal about how to best acquire and process these giant images from our very complicated camera."
The pictures also reveal intriguing details that scientists plan to re-examine once the primary mission starts.
"I personally was bowled over by the range of different geological processes that operated at different times and scales that could be discerned from a 'single' HiRISE image," science team member Laszlo Keszthelyi of the U.S. Geological Survey said.
New and improved
The images released this week include an improved version of the March 24 image and six other black-and-white images. Each of the pictures is actually a mosaic of as many as 10 images made by 10 CCD detectors.
Two of the images were part of a "jitter" test, an experiment to see how other science instruments and spacecraft systems might affect HiRISE imaging. HiRISE team members are developing image processing techniques to correct parts of the pictures that may be smeared or distorted as the result of other spacecraft operations.
The team also released a central swath of the March 24 picture as a color-coded infrared image.
Low-angle illumination didn't give the scientists the best color data, McEwen said. "But this first image nevertheless shows some very interesting and informative color variations" that look promising for color imaging when the spacecraft reaches science orbit in September, two months before the science mission begins.
HiRISE team members from USGS-Flagstaff derived a digital elevation model for part of the March 24 image, and from that they produced a topographic map and a series of perspective views. The team released the map as well as five of the perspective views. The low sun angle that detracted from color mapping enhanced the topographic views.
Conditions were far from ideal when the HiRISE camera took its test images. The camera was designed for its science orbit, a two-hour orbit at 190 miles (300 kilometers) above the planet at around 3 p.m. on Mars' dayside, McEwen said.
In contrast, the test images were taken while Mars Reconnaissance Orbiter was in a highly elliptical path that took 35 hours to complete and came closest to Mars on its night side. This flight path geometry gave HiRISE only 10 minutes of useful imaging time during each of its two orbits, and test images had to be taken at around 7:30 a.m., when the sun was barely over Mars' horizon, from a distance of 900 to 1,500 miles (1,500 to 2,500 kilometers) away.
The images have been posted on several Web sites maintained by NASA and the University of Arizona's Lunar and Planetary Laboratory:
This report is based on information from the .
