NASA held on press conference on Wednesday to announce the discovery of seven “earth like” rocky planets in a single solar system, Trappist-1, located only approximately forty light years away. Of the planets discovered, three of them are the right distances from their star to be considered within the solar system’s “habitable zone,” meaning they each could potentially have liquid water on their surfaces and even harbor alien life.
NASA’s staff announced that a number of these planets likely have surface temperatures ranging from zero to one hundred degree Celsius, making them veritable Utopias compared to the harsh environments found on most celestial bodies outside of the Earth.
While this discovery does not represent the closest planet to earth that could potentially be habitable, as Proxima Centauri has at least one planet within the “goldilocks” or habitable zone only four light years from earth, Trappist-1 represents the largest gathering of potentially earth-like planets ever discovered in a single solar system – meaning more potential spots for life to start.
Trappist-1 centers around a red dwarf star, which is significantly smaller and dimmer than the sun at the center of our own solar system. At barely 11% the size of our sun, Trappist-1’s star has a surface temperature of less than half of our own (which measures at approximately 10,000 degrees Fahrenheit). Trappist E, the inner-most planet in the habitable zone and fourth from the star, travels around the star in only a matter of days, and has an orbit approximately five percent the size of earth’s. It is also believed that Trappist E as well as a number of the other planets in the system may be tidally locked, meaning one side of the planet exists in perpetual day, while the other faces outward, like our own moon’s orbit around the earth.
Despite its proximity to the star, Trappist E receives just about the same amount of light as we do on earth. Trappist F, the fifth planet in the system, has a nine-day orbit and receives about the same level of light as Mars. Trappist G, the third planet in the habitable zone, is slightly larger than the Earth (13%) and receives only about as much starlight as the region of our solar system between Mars and the asteroid belt.
Of the three planets, scientists believe Trappist F, the fifth closest planet to the star, could potentially be rather wet, with liquid water oceans on its surface and the greatest potential for alien life to develop. Even if it hasn’t already, Trappist-1’s star is slow burning, with a lifespan that could extend a thousand times longer than that of our own star, meaning life could still potentially develop in the future.
While there is currently no way to identify life on any of these planets if it already exists, the James Webb Space Telescope slated for launch in October of 2018 will likely be able to better assess the composition of each planet’s atmospheres – enabling NASA to determine if the makeup of the gasses surrounding the planets could potentially permit life as we know it. Additionally, it’s possible that the James Webb may be able to identify elements like oxygen, which could be a strong indicator of life on the surface, as oxygen is often produced as a byproduct of photosynthesis.
With somewhere in the neighborhood of five thousand exoplanets discovered in recent decades, and dozens of them within the habitable zones surrounding their stars, the discovery of so many rocky planets in close proximity to earth around a single star seems highly unusual, but could be just the first planet dense solar system we discover in our celestial neck of the woods. According to one scientist attending the press conference, this discovery indicates that “Finding a second earth is not just a matter of if, but when.”
Images courtesy of NASA