Taking advantage of Mars's closest approach to Earth in eight years, astronomers using NASA's Hubble Space Telescope have taken the space-based observatory's sharpest views yet of the Red Planet. NASA is releasing these images to commemorate the second anniversary of the Mars Pathfinder landing. The lander and its rover, Sojourner, touched down on the Red Planet's rolling hills on July 4, 1997, embarking on an historic three-month mission to gather information on the planet's atmosphere, climate, and geology.
The telescope's Wide Field and Planetary Camera 2 snapped images between April 27 and May 6, when Mars was 54 million miles (87 million kilometers) from Earth. From this distance the telescope could see Martian features as small as 12 miles (19 kilometers) wide. The telescope obtained four images (see PIA01587), which, together, show the entire planet.
This image is centered on the dark feature known as Syrtis Major, first seen telescopically by the astronomer Christian Huygens in the 17th century. Many small, dark, circular impact craters can be seen in this region, attesting to the Hubble telescope's ability to reveal fine detail on the planet's surface. To the south of Syrtis a large circular feature called Hellas. Viking and more recently Mars Global Surveyor have revealed that Hellas is a large and deep impact crater. These Hubble telescope pictures show it to be filled with surface frost and water ice clouds. Along the right limb, late afternoon clouds have formed around the volcano Elysium.
This color composite is generated from data using three filters: blue (410 nanometers), green (502 nanometers), and red (673 nanometers).