NASA Discovers Seven Planets That Might Look Like Earth
After several days of excited speculation, NASA has announced the discovery of seven exoplanets similar in size to Earth in the TRAPPIST-1 star system at a briefing in Washington, D.C. The press conference brought an end to countless rumors, but opened the floor for new questions about whether or not any of these new planets have water, oxygen, or even alien life.
A team of scientists from NASA’s Jet Propulsion Laboratory in Pasadena used the Spitzer Space Telescope to identify seven exoplanets in orbit around TRAPPIST-1, a star located approximately 40 light-years (235 trillion miles) from Earth. TRAPPIST-1 (unfortunately named after the Transiting Planets and Planetesimals Small Telescope in Chile) is an ultra-cool dwarf star that is much smaller and colder than our own, which means that the habitable zone where liquid water could form is much closer to the star than in our own solar system. Nonetheless, scientists were stunned to discover seven planets locked to the ultra-cool dwarf. All are in an orbit closer to their star than Mercury is to our own Sun. The six inner planets are thought to be rocky and roughly the same mass as our own planet and with a similar surface temperate. Researchers were even more surprised to find three planets in the habitable zone.
This is the largest number of Earth-sized planets ever found and the largest number of potentially habitable worlds discovered in one star system! Standing on the surface of any of these alien worlds would be an amazing experience. All seven planets orbit so close to their host star that a person standing on any one of them could look up at the sky and see entire planets that look larger than the moon at night on Earth. Observers could see clouds, mountains, and oceans on a neighboring planet just by looking up at the sky!
We don’t know for sure if any of the three potential “Earths” has water, an ozone layer, or an atmosphere. But three entire planets have the right ingredients to sustain liquid water, an essential precursor for biological life. It’s possible that the exoplanets are “tidally” locked to TRAPPIST-1. This means that the same side of the planet is always locked in place facing the star, and one side is trapped in perpetual darkness, giving them extreme winds and bizarre weather patterns. NASA plans to take a closer look using the upcoming James Webb Space Telescope, scheduled for launch in 2018. The Webb Telescope can identify the chemical fingerprints of water, methane, oxygen, ozone and tell us if scientists have discovered three new potential homes for the human race—just 235 trillion miles away.
Learn more from the team of scientists that discovered the seven exoplanets and see artist’s visualizations of what these alien worlds could look like in this video from the NASA Jet Propulsion Laboratory. You can also find a multimedia presentation of all they know about these seven wonders of space here.