TRAPPIST-1: Are we Alone in the Universe?
by Jasmine Pabla
Imagine standing on a planet and watching an orange orb suspended in the sky. You look up and see neighboring planets above your head; you are able to observe their mountains, oceans and clouds. Now you look back and see that the sun did not move and you exist in a constant twilight. This scene, which seems straight out of a science-fiction novel, is what life might look like if we lived on one of the exoplanets in the TRAPPIST-1 system.
On Wednesday, February 22, 2017 astronomers at NASA discovered 5 new earth-sized planets orbiting the TRAPPIST-1 star, adding to the two planets that were previously found in May, 2016. Although this is but one of the thousands of exoplanet discoveries made by NASA, this system is monumental for the scientific community. Not only are these planets in the habitable, or “Goldilocks” zone, they also have a strong likelihood of having liquid water. Right now, exploring the TRAPPIST-1 system seems to be our greatest chance of finding extraterrestrial forms of life.
TRAPPIST-1 is a dim star, slightly smaller in size than Jupiter, located in the Aquarius constellation about 39 light years, or 235 trillion miles, away from the Earth. A year on one of these planets would range from 1.5 days to about 20 days due their extremely small orbit size, which is smaller than the orbit of Mercury around our Sun. In addition, scientists speculate these planets are tidally locked, which means that the exoplanets do not rotate on an axis and therefore each side of the exoplanet is in a perpetual state of day or night.
The discovery of these exoplanets was made by the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) and Spitzer telescope. Researchers used a method called “Transit Photometry”, which focuses on the dimming of a star’s light caused by a passing exoplanet, to locate these exoplanets. From this data, scientists can also calculate the size of exoplanets orbiting around the star.
Using information from these telescopes, researchers at NASA have precise size measurements of 6 out of the 7 planets and can estimate masses and densities of the planets based on their orbit length. The calculated densities indicate these exoplanets are rocky in nature, like Earth; six of these planets are in a temporal zone and have surface temperature between 0 and 100 Celsius. In addition, 3 of these planets have the capability to have oceans, thereby increasing the odds that these exoplanets may harbor organic life.
However, scientists cannot draw conclusions just yet. Using combined data from the Spitzer, Hubble and Kepler telescopes, NASA astronomers will have enough information to launch the new James Webb Space telescope in 2018. This telescope has the capability to detect chemicals present in each of the exoplanet’s atmospheres such as water, methane and oxygen: all important components of organic life. According to Sara Seager, an astronomer at the Massachusetts Institute of Technology, “For the first time ever, we don’t have to speculate. We just have to wait and then make very careful observations and see what is in the atmospheres of the Trappist planets.”
The atmospheres of the exoplanets are not the only strong indicator of potential life. The TRAPPIST-1 star is still in its infancy and due to its slow burning of hydrogen, and scientists speculate that it could burn for another 10 trillion years. Ignas Snellen of the Leiden Observatory in the Netherlands notes that: if organic life has not been found yet, there is enough time for it to evolve.
The discovery of these exoplanets has excited both the space community and science-fiction community. Dr. Chris Copperwheat, an astronomer who co-led the international team said, “The discovery of multiple rocky planets with surface temperatures which allow for liquid water make this amazing system an exciting future target in the search for life.” There is now a greater shift in creating more sensitive technology to get a more detailed picture of possible life-harboring exoplanets. Launching the James Webb Telescope is just the beginning.
While it is too early to confirm that there is water or organic life on these exoplanets, their location in the orbitals, proximity to the TRAPPIST-1 star and rocky nature give a perfect environment for organic life to evolve. The chemical makeup of each atmosphere is the last piece to the puzzle. This monumental event could lead to the first discovery of “alien” life forms. Astronomers are hopeful about the launch of the new James Webb Space Telescope and the answers it could bring about this new system. With a new shift towards improving exoplanet space technology, the future looks bright for the dim TRAPPIST-1 star.