Scientists have stumbled across an exciting new lead in the search for extraterrestrial life. After analyzing data collected from NASA’s Kepler orbiting observatory from March 2009 to May 2013, researchers have discovered the most Earth-like exoplanet yet with a promising potential for sustaining life.
Circling the star Kepler-186, is a planet appropriately named Kepler-186f that is only about 10% larger than Earth and orbits within Kepler’s habitable zone. The habitable zone is a radius around a star that permits temperatures that allow water to exist in a liquid state.
Kepler-186f is about as far away from its respective star as Mercury is from our sun. However, as a red dwarf star, Kepler-186 is about half the size of and much cooler than our sun. If Kepler-168f were any closer to Kepler-186, it would be tidally locked which means that only one side would permanently face the star. This would make it almost impossible to sustain life because of the resultant extreme temperatures. Fortunately, Kepler-186f is not this close to its respective star; however, its relative proximity makes it more susceptible to solar flares.
Kepler-186 is actually an M star, which means it is classified as the coolest and most abundant type of star in the universe. M stars burn for millions of years longer than G stars like our sun, and experts reason that this would allow more time for life to develop. The entire scale of star classifications from hottest to coldest ranges as follows: O, B, A, F, G, K and M.
Earlier planets discovered in their respective habitable zones have been substantially larger than Earth and therefore more likely to be gaseous than rocky. Kepler-186f’s small size is just another promising characteristic in the search for otherworldly life.
There are a total of five planets orbiting Kepler-186, which is about 500 light years away from Earth. Researchers discovered the Earth-like planet by carefully observing the brightness of Kepler-186 over a period of four years. Whenever the brightness dimmed, scientists were able to deduce the size of the object passing in front of it. The Kepler orbiting observatory has been evaluating around 150,000 stars over the four-year period mentioned earlier and have since identified almost 4000 planets with life-sustaining potential. Kepler-186f however, has been by far shown the most promise.
The first exoplanet was discovered almost twenty years ago when a Swiss team revealed that they had discovered a body circling the star 51 Pegasi. This kicked off a flood of planetary discoveries as technological capabilities advanced to incredible new heights.
Researchers and novice enthusiasts alike have marveled at the night sky for hundreds of years. If you would like a greater glimpse at our universe, please take the time to visit the free Maryland Space Grant Observatory in Bloomberg Hall on Friday nights at 8pm. Perhaps you will formulate your own opinions on the age-old question, “Are we really alone?”
