Ray Arvidson, deputy principal investigator for NASA’s Mars Exploration Rover Mission, will speak about the mission’s newest discoveries at 3 p.m. today in Davis Hall, Room 121.

Arvidson, who is also an earth and planetary science professor at Washington University in St. Louis, will discuss the scientific aspects involved in the planning of the mission, said Wei Luo, professor of geography. Arvidson specializes in where the rovers should go and knows what is interesting to look for, Luo said.

“There is a big team involved, and Arvidson is an expert on this subject,” Luo said.

Arvidson said there are 50 scientists involved with the project and he is the second in charge. He has worked mainly with the rover, Spirit. Arvidson also led a team that put together plans and sequences for the mission.

The rovers have a rock abrasion tool that scrapes the rock’s surface and goes in deeper to analyze the rock, Luo said.

In January, the rover Opportunity found sedimentary rocks, and in June, Spirit found the same, Arvidson said. Sedimentary rocks form in the presence of water, which could be signs of past life.

“If there are signs of water, it increases the chance that life got started,” Arvidson said.

More exploration needs to be done for safety reasons, Luo said.

In time, astronauts may be sent to Mars to better investigate, Arvidson said. They would go back with more sophisticated instruments and look for fossils and other organic materials.

“We’re totally pumped – the mission was a complete success,” Arvidson said.

Both Opportunity and Spirit surpassed their designed life expectancy, Luo said.

The Mars Exploration Rover Mission was launched toward Mars June 10 and July 7, 2003, according to its Web site, http://mars.jpl.nasa.gov. A goal for the rover is to drive up to 40 meters in a single day for a total of about three-quarters of a mile.

Arvidson last visited NIU in 1999 when the mission was still being planned, Luo said.