Now, he's doing it again, but this time he's not leaving the planet.

Pettit is currently in Antarctica on a scientific expedition to look for meteorites. Even though he's still on Earth, the trip will have a lot in common with his ISS stay as part of the Expedition 6 crew. So in addition to the search for meteorites, Pettit will be using his background for another mission -- learning more about how Antarctica can prepare astronauts to travel to the moon and Mars.

"This is an opportunity that appeals to the heart of any explorer, whether an Earth explorer or space explorer," he said. "To be able to go off on a frontier, a place where one's normal intuition no longer applies, is the essence of exploration. When in such a place, new discoveries abound, to be found simply by opening your eyes. And to be able to participate in some meaningful way with other scientific missions and gain the experience for space exploration presents an exceptional opportunity."

"Antarctica is a great match for either lunar or Martian training analogs," he said. "Antarctica has both Mars and moon analogs, depending on where you go on the continent. If you go to the dry valleys, places in Antarctica that have no snow, you have as close to a Mars environment on Earth as you can get. If you stay on the ice sheets, you have more like a lunar setting where the geographic contrast is self-similar without the rich resources that we are use to on a planetary surface (like Earth and Mars). Where we will be going is the ice sheets, and this should be more akin to a lunar analog setting."

Another thing this trip will have in common with his space station mission is that Pettit will be sharing his experiences with the public. While on ISS, he kept a journal of his experiences, "Space Chronicles," which was published online. During his stay in Antarctica, Pettit will be posting a new series of updates, "Space Chronicles on Ice." The focus of the series will be contrasting exploration in space with exploration on Earth.

"In my preconceived expectations, I believe that there are many similarities between space exploration and Antarctic exploration," he said. "However, the actual outcome of this is to be determined once I have some Antarctic experience to compare things to."

He also plans to supplement his research there with some personal experiments, as he did in orbit. "Just like on space station, there will be some time available for your own use," he said. "Instead of reading books, I plan to do some of my 'Saturday Morning Science,' on ice. I have a number of simple experiments in mind dealing with the uniqueness of the Antarctic environment."

Pettit's time in Antarctica won't be all work, however. He plans to dedicate some time to pursuing a long-time hobby. "I have been collecting snowflakes ever since I was in middle school," he said. "I have a special plastic resin that is dissolved in a solvent that allows me to make a plastic cast of a snowflake. Then, when the snowflake melts, you have a plastic replica. This is sort of like making plaster casts of animal footprints. Every time I venture off to someplace cold, I bring my snowflake kit, and I am planning to collect snowflakes on this expedition to Antarctica."

Pictures of snowflake casts made during his stay will be published on his journal, he said.

The Antarctica Search for Meteorites program is sponsored by the National Science Foundation. The meteorites that are collected will be brought to NASA's Johnson Space Center for analysis.

Now is a particularly fitting time to be visiting the polar region of the planet. 2007 marks the beginning of the International Polar Year, a period of global scientific focus on the Earth's polar regions. The event marks the 125th anniversary of the first IPY, which began in 1882. Pettit said that the study of this region is vital to understanding our planet as a whole.

"The polar regions tend to show signs of climate change well before the rest of the planet." Pettit said. "With the Earth, for whatever reason, going through a warming phase, it is important to study what is happening at the polar regions. One hundred and twenty-five years ago, we were just learning about the polar geography and how to stay alive there. Now we have the technology and knowledge to go to polar regions and study things in far more detail without having to struggle simply to stay alive. I predict that the IPY effort for 2007-08 will bring about a host of new discoveries about our planet, and ultimately, ourselves."

Pettit's journals and science projects support NASA's continuing tradition of investing in the nation's education. NASA is committed to building strategic partnerships and linkages with formal and informal educators of science, technology, engineering and mathematics. Through hands-on, interactive educational activities, NASA is engaging students, educators, families, the general public and all agency stakeholders to increase Americans' science and technology literacy.

Related Links
Antarctica Search for Meteorites
NASA Education