NASA HiRise Image: Older sibling sees Curiosity take the plunge

(Images: NASA/JPL/University of Arizona)

Thousands of humans weren't the only ones with eyes trained on NASA's newest Mars rover last night: One of the robot's orbiting relatives captured this lucky shot as Curiosity descended onto the Red Planet.

The HiRISE camera aboard NASA's Mars Reconnaissance Orbiter was in position to observe Curiosity as it plunged through the Martian atmosphere during its harrowing Entry, Descent and Landing phase, also called the "7 minutes of terror".

Seen about a minute before touchdown, Curiosity is still tucked into its backshell, part of the larger spacecraft that encased the rover during its roughly eight-month trek from Earth to Mars.

The craft is attached to its 16-metre-wide supersonic parachute, which slowed Curiosity's descent speed from 400 metres per second to 80 metres per second in less than two minutes.

A closer cutout view of the spacecraft and its chute (above left) was processed to avoid saturation, presenting better detail.

Shortly after this picture was taken, Curiosity let go of the backshell and fired up its retrorockets, beginning a powered descent that would end in the innovative but risky Sky Crane manoevre, with the rover being lowered on cables to land wheels first near a Martian mountain.

This isn't the first time HiRISE has watched over a new arrival on Mars. In May 2008 the orbiting camera spied NASA's Phoenix lander parachuting toward the Red Planet's north polar region.

The angle of that shot made it seem as if Phoenix was headed into a large crater, although it actually touched down on smooth plains about 20 kilometres from the crater rim.

HiRISE has also taken portraits of its predecessors, including the defunct rover Spirit and its still-operational twin, Opportunity.

"Guess you could consider us the closest thing to paparazzi on Mars," HiRISE team member Sarah Milkovich, of the Jet Propulsion Laboratory in Pasadena, California, said in a NASA statement.

Still, getting a bead on Curiosity during its descent was not guaranteed. The HiRISE team had just one chance to get an image as Curiosity passed through the orbiter's field of view.

"If HiRISE took the image one second before or one second after, we probably would be looking at an empty Martian landscape," says Milkovich.