One year in, NASA’s exoplanet-discovering mission has promising results
We learn about the planets and solar system as early as elementary school, but our understanding of the Universe is constantly growing. As much as we don’t know about our own solar system, the Universe holds even more mysteries—light years away from our home here on Earth.
For decades, NASA researchers have looked for exoplanets, or planetary bodies that exist outside of our solar system. This is the first step to locating life beyond the solar system. Researchers are particularly interested in exoplanets with Earth-like qualities, like certain temperature ranges and atmospheric qualities.
But we can’t locate these exoplanets just with telescopes. We have to get much, much closer to identify exoplanets. That’s why NASA launched the TESS telescope in April of 2018.
What is TESS?
TESS stands for Transiting Exoplanet Survey Satellite (TESS). Launched in April of last year, the program just celebrated its first anniversary—and has plenty of discoveries to celebrate.
TESS is on a mission to hunt down exoplanets. During its one year in space, TESS has located 24 confirmed exoplanets, with another 993 potential planets identified. We’re unsure whether these bodies are planets because TESS looks at brightness around stars. When a planet crosses the face of a star, TESS picks up on the light differences. Since other objects could cause this phenomemon, scientists still have to confirm whether these 993 incidents are exoplanets.
In its one year of exploration, TESS has exceeded NASA’s expectations. The satellite was supposed to observe only preselected stars with a high potential for exoplanets. Discovering dozens of confirmed exoplanets has exceeded all hopes for the mission.
The TESS mission will last at least two years. But in the short span of time that it’s been looking for exoplanets, TESS has expanded on work scientists have already done with telescopes on Earth.
However, TESS is giving scientists amazing data to use in future missions. For example, NASA plans to use this exoplanet data for its James Webb Space Telescope, which should be operational in 2021. At that time, scientists can use the telescope to further study exoplanets identified by TESS. Since they know where to look for the exoplanets, they can make faster discoveries.
Discovering habitable exoplanets
But of all the exoplanets TESS has discovered, two are very promising. They orbit within what’s called the “habitable zone” around their host stars. Because of where these exoplanets are in relation to their host stars, there’s a good chance there may be liquid water on their surface, which is the first step to discovering life.
However, the most promising exoplanet is in the GJ 357 star system. This planet is a super Earth, weighing in at six times the Earth’s mass. TESS first discovered the planet, dubbed GJ 357 d, in February 2019. The planet is promising because it receives the same amount of light from GJ 357 as Mars receives from our Sun.
However, light alone isn’t be a cause for excitement. The exoplanet would still need a dense atmosphere to keep the planet’s surface warm enough for liquid water.
Scientists say it’s unlikely that life will be present on the exoplanet, but it’s still a fantastic discovery. NASA plants to study GJ 357 d’s atmosphere in further missions to see if it contains water.
Although the TESS discoveries exceeded expectations, they’re a small stepping stone towards our understanding of life beyond the solar system. However, exoplanets and their star systems have a lot to teach us about the composition of celestial bodies, stars, and much more. As humanity plans to go from the Earth to Mars, missions like TESS help us continue to set our sights further beyond the stars.