Jake Matijevic
September 19, 2012

Curiosity Finds A Rock And Witnesses Its First Eclipse On Mars

Lee Rannals for redOrbit.com - Your Universe Online

Curiosity got to witness an Earth-like experience on the Martian surface last week, by watching the moon Phobos create an eclipse on Mars.

NASA unveiled new images on Wednesday, as well as an update to Curiosity's whereabouts.

On September 13, Curiosity witnessed a Martian moon transit that involved the moon Phobos coming between the Red Planet and the Sun.

The new rover snapped images of the event using its Mast Camera, which is equipped with special filters for directly observing the sun. This camera has two lenses, one of which is designed to take zoomed-in shots with about three times higher resolution.

An animation was also released by NASA that was taken from the higher-resolution Mast Camera. The animation shows the transit as viewed from the camera in nine frames.

Mark Lemmon, Curiosity's co-investigator, said studying the moon transits is important to scientists for many reasons, particularly to gain a better understanding of Phobos' orbit.

Phobos orbits very close to Mars and is slowly spiraling into the Red Planet due to tidal forces. These forces change the orbital position of Phobos over time, and the recent images will allow scientists to get a better idea of Phobos' exact orbit of Mars, and how it has changed over time.

The Viking spacecraft first observed a Martian eclipse, but that mission did not produce any pictures of the event. The Mars Exploration rovers first took images of the event back in March 2004. Curiosity adds new technology to the Red Planet moon transit research with its higher resolution cameras, and faster uploading time, according to Lemmon.

NASA said the transit events are the Martian equivalent of partial solar eclipses on Earth because the outline of the moons do not completely cover the sun. Both Phobos and Mars' other moon, Deimos, will be occasionally passing in front of the disk of the sun from Curiosity's perspective.

These transit events will be observed by Curiosity as part of a multi-mission campaign on Mars.

Curiosity's Rover Environmental Monitoring Stations (REMS) instrument also observed the event, and saw about a five percent drop in the sun's ultraviolet radiation.

NASA also said that Curiosity has traveled about 950 feet from its original landing spot since reaching the planet about six weeks ago.

The rover is a little over halfway towards the mission's first major science destination, a spot NASA is calling Glenelg.

John Grotzinger, Curiosity's project scientist, said that Glenelg was selected because it represents the intersection of three relatively different terrain types coming together.

Part of the area that will be observed by Curiosity at Glenelg is a "light-toned unit" that NASA believes holds a material that is able to retain heat.

Grotzinger said that late in the day, or at night, orbiters are able to observe this area fairly well because it is still giving off heat.

"We don't know the reason for this," he said during the press conference, "but it has always been a beacon to us."

Glenelg also holds some "dark bands" that Grotzinger said they are not exactly sure what they are, but they obviously form different layers.

Curiosity will be coming up to a rock NASA has picked out as a suitable target for the rover's first contact instruments. This rock has been named "Jake Matijevic."

Matijevic was the surface operations systems chief engineer for the Mars Science Laboratory Project, and the project's Curiosity rover. He also was involved in previous rover missions like Sojourner, Spirit and Opportunity.

Richard Cook, Curiosity's project manager, said they chose to name the rock Jake Matijevic as an honor to him because was a very instrumental rover engineer. Matijevic died a few weeks after Curiosity landed.

NASA will be targeting the rock with Curiosity's Alpha Particle X-Ray Spectrometer, which can read a target's elemental composition. Curiosity will also be using its Mars Hand Lens Imager to get close-up imaging of the Jake Matijevic Martian rock.

The 10-inch tall, 16-inch wide rock currently is lying about 8-feet from the rover. Cook said NASA plans to do three or four days´ worth of scientific research on the rock before moving on.