NASA's Curiosity rover is three months into its two-year mission on Mars as it investigates whether conditions there ever could have supported microbial life. Researchers are interested not only in ancient Mars but present-day Mars so they can plan future travel to the Red Planet.
In the past 12 weeks, the Curiosity rover has scooped up Martian soil, sampled the atmosphere, mapped wind and radiation patterns, and monitored changes in air pressure on Mars.
The car-sized rover is exploring near the foot of a peak called Mount Sharp within a deep, 150-kilometer-wide depression called Gale Crater. The overall goal of NASA's $2.5 billion Mars Science Laboratory mission is to use Curiosity's 10 scientific instruments to learn if Mars ever offered a habitable environment for micro-organisms.
NASA's Ashwin Vasavada, the deputy project scientist, told reporters that the mission is mostly focused on the habitability of ancient Mars. But, he says, researchers also want to learn about the modern day environment there.
"It's a pretty dynamic environment. If you were standing next to Curiosity, you'd realize you're on a planet with an atmosphere -- an atmosphere that is thick enough that when the sun heats the ground every day, gusty winds rush up and down the slopes of Gale Crater and Mount Sharp and spawn whirlwinds that sweep across the landscape. But the atmosphere isn't thick enough to shield you from the harsh ultraviolet light and the natural high-energy radiation coming in from space," Vasavada said.
Understanding the radiation is critical. Curiosity is equipped with a Radiation Assessment Detector, known as RAD. Don Hassler is the radiation detector's principal investigator.
"The radiation is a life-limiting factor to habitability, so we need to understand what the radiation is doing if we want to understand the prospects for both current and past habitability, but we also need to understand the radiation environment. When we send astronauts to Mars in the future, we need to be able to fully understand what the radiation is doing so that we can help plan a safe mission for those astronauts," Hassler said.
President Barack Obama has challenged the U.S. space agency to send humans to Mars in the 2030s.
Hassler notes that NASA has established a career radiation-dose limit for astronauts.
"I think it's never really been a question of if we can go to Mars. It's a matter of when we go, how do we best protect our astronauts, so characterizing the radiation environment in terms of the types of radiation that we observe and when it's the worst and when we'd need to take precautionary measures, I think, is one of the things that we're learning from RAD," Hassler said.
Researchers say Curiosity is providing measurements that will help scientists design a human mission to the Red Planet.