Mars makes the list of ET-friendly planets

In November, a team of astrobiologists proposed two new planetary rating systems that could help widen the search for extraterrestrial life. They suggested ranking planets on both an Earth Similarity Index (ESI) and a broader Planetary Habitability Index (PHI). Wired provided the following explanation of the two systems:

The first index looks at how close a planet is to Earth in mass, temperature, and composition while the second is based on the whether or not it possesses more exotic chemistries, liquids, and energy sources than found on our planet. Alien life could be based on elements other than carbon, require liquids other than water, and gain energy through means other than sunlight.

According to the International Business Times, the team of researchers has used their new rating systems to develop lists of planets and moons with the highest probability of hosting extraterrestrial life.

Here is the list of most livable planets and moons using the ESI:
• Earth – 1.00
• Gliese 581g – 0.89
• Gliese 581d – 0.74
• Gliese 581c – 0.70
• Mars – 0.70
• Mercury – 0.60
• HD 69830 d – 0.60
• 55 Cnc c – 0.56
• Moon – 0.56
• Gliese 581e – 0.53

Here is the list of most habitable planets using the PHI:
• Earth – 0.96
• Titan – 0.64
• Mars – 0.59
• Europa – 0.49
• Gliese 581g – 0.45
• Gliese 581d – 0.43
• Gliese 581c – 0.41
• Jupiter – 0.37
• Saturn – 0.37
• Venus – 0.37

Based on these lists, life on Mars looks pretty favorable. The year 2011 has been filled with Mars discoveries. Recent findings suggest the presence of flowing water on the planet’s surface, at least seasonally. Scientists also recently determined that large underground regions on Mars might be habitable. NASA’s Curiosity rover, the world’s biggest extraterrestrial explorer, will reach the planet in mid-2012, and will search for signs of life. And while life might already exist in the favorable conditions on the red planet, one visionary here on Earth wants to colonize Mars.

Elon Musk, co-founder and CEO of SpaceX, recently stated that he “wants to put 10,000 people on Mars,” according to New Scientist. He reportedly went on to say, “Ultimately we don’t really want 10,000 people on Mars . . . We want millions.” And he claims he can do it for as little as $2 billion.

Earlier this year, Musk announced SpaceX’s plans to develop a fully reusable space launch system. He stated, “We’ve not gone beyond Earth’s orbit in a generation. I want to change that. Rapid reusability is what will take us to Mars.” The SpaceX launch vehicle that could take humans to Mars is the company’s new Falcon Heavy, which is scheduled for testing in 2013. So pack your bags. A trip to Mars is right around the corner.