Tuesday, March 10, 2015

The Transit Method



One of our current best methods for finding and understanding Extrasolar planets is called the Transit method. Like its name, the Transit method finds transiting planets, or planets that pass in front of their stars by looking at tiny brightness dips when a planet crosses in front or even behind a star. (The only reason I know something about this technology is because I'm taking an online course through Harvard called HavardX: SPU30x Super-Earths and Life.)


Lead and introduced by Professor Dimitar Sasselov, the class covers a wide range of information starting from our basic understanding of life down to the molecules of our DNA, in connection to the new discovery of Exo-planets (Earth-like planets) in the Universe similar to ours that may hold life. Uniting physics, biology, molecular biology, chemistry and astronomy, this is called Astrobiology, and scientists like Sasselov have joined in the hunt for Alien worlds with extraterrestrial life.


And no wonder. No longer science fiction, many such planets continue to be discovered with the Kepler Telescope that was launched from Florida on March 6, 2009. For six years this Kepler mission has cruised around the sun taking pictures of the galaxy finding multitudes of alien planets using this Transit technology. Although Kepler had a couple of malfunction setbacks in 2013, it continues to find planets and Nasa now lists 1,821 confirmed planets, with 463 multi planet systems.


Spurred on by the first discovered Super Earth by Aleksander Wolszcsan in 1992, astronomers and planet scientists became increasingly interested especially when they discovered some of these Kepler planets or "Super-Earths" are also in the circumstellar habitable zone or CMZ. Also known as the Goldilocks zone this term describes the region around a star within an orbit that supports habitability. Narrowing down the potentially habitable planets to about 29 so far, these planets have names like Kepler-442 b, Kepler-283 c and GJ-667 c. Considering some of these Exo-planets are the same make up as Earth, with similar sizes, a rocky surface, liquid water and atmospheric pressure, the scope of this information is - well... for lack of a better word - astronomical. Due to the importance of liquid water to life as it exists on Earth, these planets could hold life. Extraterrestrial life and possible intelligent life. In fact so many planets have been found on November 4, 2014 astronomers reported, based on the Kepler space mission data there could be as many as 40 billion Earth sized planets orbiting within the Goldilocks range.


The passage of a smaller celestial body or its shadow across the disk of a larger celestial body or Transit seems to have opened a few eyes, and confirmed a few long standing theories about the possibilities of intelligent life outside of our own planet. Although this information is daunting, it also seems fitting how the very word transit, also embodies a remarkable transition into what we always knew but could never prove until now.


We are left hanging on the edge of our seats as we question what this information might tell us someday. I do hope though, that when we do find life out there, whatever it may be, someone like Sasselov can shake their finger at the world and say, "I told you so."


http://kepler.nasa.gov/Mission/discoveries/kepler10c/