How common is Earth?
In the past few decades, there has been an explosion in the number of planets discovered beyond our Solar System. With over 4,000 confirmed exoplanets to date, the process has gradually shifted from discovery towards characterization. This consists of using refined techniques to determine just how likely a planet is to be habitable.
Ever since the first exoplanet was confirmed in 1992, astronomers have found thousands of worlds beyond our Solar System. With more and more discoveries happening all the time, the focus of exoplanet research has begun to slowly shift from exoplanet discovery to exoplanet characterization. Essentially, scientists are now looking to determine the composition of exoplanets to determine whether or not they could support life.
In February of 2017, astronomers from the European Southern Observatory (ESO) announced the discovery of seven rocky planets around the nearby star of TRAPPIST-1. Not only was this the largest number of Earth-like planets discovered in a single star system to date, the news was also bolstered by the fact that three of these planets were found to orbit within the star’s habitable zone.
For a long time, the idea of finding life on other worlds was just a science fiction dream. But in our modern times, the search for life is rapidly becoming a practical endeavour. Now, some minds at NASA are looking ahead to the search for life on other worlds, and figuring out how to search more effectively and efficiently. Their approach is centered around two things: nano-satellites and microfluidics.
NASA astronomers working with data from the Kepler space observatory have presented the largest single crop of newly discovered exoplanets to date. It’s impressive – 1,284 new planets have been announced, including around 550 which are of comparable size to the Earth. However just nine of these may be in their stars' habitable zones – where it is plausible that liquid water could exist on the surface of a planet.
Observations from NASA's Spitzer Space Telescope have led to the first temperature map of a super-Earth planet -- a rocky planet nearly two times as big as ours. The map reveals extreme temperature swings from one side of the planet to the other, and hints that a possible reason for this is the presence of lava flows.