A new global map of Mars provides a new perspective of the planet.
The map, released earlier this month, was pieced together from 3,000 images taken by the United Arab Emirates’ Hope spacecraft, and shows the Red Planet in its true light.
“These are all natural colors on Mars,” said Dimitra Adri, a research scientist at the Space Science Center at NYU Abu Dhabi.
Hope’s main science mission, which entered Mars orbit two years ago, is to study how dust storms and other weather conditions near the surface affect the speed at which Martian air leaks into space.
But the orbiter also carries a camera.
When Dr. Adri Hope saw the first image he sent back, he said, firstatest the first time that he sees the first image that I sent back, the quality of the image displayed on the entire disc. “I’ve never seen Mars like this.”
Maps of Mars are nothing new. In the 1890s, American businessman Percival Lowell used his fortune to build the Lowell Observatory in Flagstaff, Ariz., and while he peered at Mars through a 24-inch telescope, he sketched what he thought were artificial canals built by a Martian civilization. (He observed telltale structures on Venus; it was later demonstrated that he may have inadvertently mirrored his telescope and seen the back of his own eyeball.)
During the space age, numerous spacecraft passed by or entered orbit around Mars.
But earlier orbiters such as NASA’s Mars Global Surveyor and Mars Reconnaissance Orbiter typically moved very close to the Martian surface, typically in orbits designed to make repeated passes above a given location in a single day. Those images provided sharp details of the surface, including sand dunes, craters and boulders rolled down from the mountains.
“They are wonderful, fascinating images,” Dr. Adri said. “But you can’t see the whole planet at once.” The varying lighting conditions from place to place made it difficult to consolidate a single, global vision.
Lighting conditions are not a problem for other types of maps. The Global Surveyor carried an altimeter instrument that beamed a laser beam off the surface. By measuring the time it takes for a pulse of light to travel across the surface and back, the instrument can measure every nook and cranny on the surface and the height of the brain. Scientists used the data to create a detailed landscape map.
For views in visible light, the Hubble Space Telescope in Earth orbit can see an entire side of Mars. Scientists stitched together several such images into a global map, similar to a new map of the space shuttle Hope.
But Mars is almost 34 million miles from Earth, so the Hubble images are not as sharp. Hope travels around Mars in an elliptical orbit ranging from 12,400 miles to 27,000 miles above the Martian surface. It is significantly higher than the Mars Reconnaissance Orbiter, but much closer than Hubble.
“We thought, well, we’ve got to have an atlas because in years we’ll be able to photograph Mars,” Dr Adri said. “So we first need to have an atlas where we not only map the entire planet, but show how it changes throughout the Martian year.”
Dr Adrial was able to find images with similar light levels, excluding images where clouds obscured the surface. The process took months. “It’s very difficult to get rid of all the borders and stuff,” he said.
Dr. Atri said he and his colleagues are currently writing a scientific paper to describe the mechanism they developed. The same method could be used for other world-bound spacecraft, including the European Space Agency’s Jupiter IC Moons Explorer or JUICE, which launched on Friday.
“These icy moons are very beautiful,” said Dr. Atri. “So we can use the same technique.”
