1. Ancient Mars could have had the right chemistry to support living microbes. Curiosity has found carbon, hydrogen, oxygen, phosphorus, sulfur and hints that there was once fresh, flowing water.
2. Evidence of an ancient streambed. Smooth, rounded rocks were found that suggest a steady stream of flowing water about knee deep.
3. Radiation levels on Mars exceed NASA’s career limit for astronauts. Curiosity detected the Red Planet could be dangerous for humans explorers if they’re not properly protected.
4. The lack of methane in the air (so far). Living organisms release methane so Curiosity was hoping to detect it, but so far has sniffed none.
5. The unexpected diversity of environments near the landing area. Curiosity has found gravels, streambed deposits, an unusual type of possibly volcanic rock, water-transported sand dunes, mudstones, and cracks filled with mineral veins.
Read more first anniversary news:http://1.usa.gov/18ZB6YI and find out more about the seven minutes of terror:http://bit.ly/LNLxTh