Space: the Final Frontier.
Each day, that vast emptiness appears just a little less infinite. On Feb. 22, NASA proved how far we’ve come in our ability to explore and discover without ever leaving Earth. On that day, it announced the discovery of four more planets surrounding the star known as TRAPPIST-1, 40 light years from Earth.
All four planets are terrestrial—meaning they are possibly as habitable as Earth—bringing the total tally of habitable planets in the system to seven.
The word TRAPPIST has nothing to do with Fetty Wap or Admiral Ackbar; instead, TRAPPIST is an acronym that stands for TRAnsiting Planets and Planetesimals Small Telescope (though this was inspired by the beer created by Trappist monks). The star is the first with exoplanets that the telescope has discovered, and thus it is designated TRAPPIST-1.
The interesting characteristic about the technology is that the telescope doesn’t directly observe the planets, which would be impossible due to their distance. Instead, the telescope relies upon the “transits” of the planets: hence the “transiting” in the name of the telescope.
The telescope measures the light given off by the star; when an object, such as a planet, passes in front of the star, the brightness dims by a small amount determined by the relative sizes of the star and the planet.
There are other methods of observation, such as calculating the effects of the planet on the star’s orbit, that reveal the mass of the planet. This can lead to the calculation of other characteristics of the planet, such as its density and its physical composition.
Using this method with TRAPPIST lets scientists discover much about planets and stars by simply observing their effects and never having to view them directly.
Scientists will soon also be able to discover a lot more about the planets. Currently, they know that the planets have potential for life because of their similar sizes to Earth and their relative distance from their own star. However, soon they may be able to know the composition of the planets’ atmospheres, a crucial step to truly understanding them.
In 2018, NASA will launch the James Webb Space Telescope, a telescope with unprecedented sensitivity to certain wavelengths that are useful for making astronomical discoveries. Using the telescope, scientists will be able to see a ring around each planet, caused by starlight piercing through their atmospheres. The fluctuating colors of the rings will allow the scientists to determine what molecules the light is hitting, and thus determine the composition of each planet’s atmosphere.
The discovery of different atmospheric conditions will be enlightening for scientists. They may be able to determine if the planets have global oceans, like Earth, or even estimate the greenhouse effect’s influence on each planet, allowing for a prediction of the planet’s temperature. Other gases, like ozone or methane—often emitted by bacteria—are very important. Ozone and methane balanced with carbon dioxide and water has only one obvious explanation: life.
Discovering the exoplanets of TRAPPIST-1 is hugely significant, yet it is only the beginning. It represents the opportunity for furthering the understanding the emptiness around Earth—and reveals that space really isn’t so empty. This is still just the beginning of the quest to find life. Only time will tell if Earth is really alone.
