The Mars Curiosity rover mission has proved a smashing technological success for NASA, with 157 days spent by the rover on Mars providing a wealth of "firsts" and key information about the planet, said Michael Meyer, lead scientist for NASA's Mars exploration program.

Meyer relayed some of the mission's accomplishments to a gathering of geology students Wednesday afternoon at UC Davis. He also spoke to The Bee about the mission.

One of the goals of the two-year mission is answering the question of whether Mars was once hospitable to life.

So far, the rover's findings suggest it may have been, but the "smoking gun" – evidence that would establish the presence of organic material on the planet – has yet to be found.

Meyer said that establishing a stable presence of water is a key aim and one of the reasons the Gale crater landing spot on Mars was selected.

The rover is traveling from the crater to a mountainous rise named Mount Sharp, where rock is arranged in layers that can be read like a historical map of geologic and other activity on Mars.

Recent photographs taken by the rover's cameras reveal not only stunning vistas, but also the presence of unexpected items, such as pebble-shaped rocks.

On Earth, such pebbling is indicative of water erosion borne from flowing bodies of water.

"It looks like there was a period of time that water was stable on the surface of Mars," Meyer said. "Now we have to find the things that life uses to make the structure: organic compounds. That's the holy grail."

Meyer said it is possible the rover could find that proof soon, and possibly within the month, when an instrument will shoot lasers into rock and analyze what is vaporized.

"This is cool because it's all new to planetary science," Meyer said.

So far, the Curiosity mission – a veritable lab on wheels – fulfills NASA's third step in a five-step process set out by NASA in 1995 for Mars exploration.

Step one was planet reconnaissance. Step two was placing a rover on the planet.

Step four will involve the return of Martian samples to Earth – a mission that is destined to happen in 2020. The last is sending humans to Mars.

The rover's 10 instruments include a radiation monitor that may go a long way to establishing the likelihood and cost-effectiveness of step five.

NASA has been tracking radiation levels since the rover left Earth's atmosphere on its eight-month, 352 million mile journey to Mars that began in November 2011.

The findings suggest that space radiation will be an issue for astronauts on any manned space mission to Mars – an endeavor some say will not happen until 2030.

"What we've found is the radiation levels are on the order of two times what an astronaut gets on a space station," Meyer said.

The rover's radiation findings were described by Meyer as "pretty harsh."

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