When we are kids, we study space in school. We memorize a mnemonic to remember the planets: “my very educated mother just served us nine pizzas,” although now it would be my very educated mother just served us noodles. (Poor Pluto!) We take field trips to the planetarium, recline in the uncomfortable chairs, and gaze at a sky that seems wondrous beyond our grasp. As adults, we learn the constellations and look at Venus and Jupiter when they are visible in the night sky. We take note of what meteor showers are coming up and when the space station can be seen with the naked eye.

Space is fascinating and there is still so much that researchers don’t know about it.

Last month, NASA took to Twitter to announce an exciting new discovery, further illustrating that there is an abundance of information yet to be learned when it comes to space. NASA’s tweet contained the simple message:

“This Week: We found 7 Earth-sized planets orbiting a dwarf star, 3 of them in the habitable zone!”

They also updated their Twitter cover photo to an artist’s rendering of what these seven new planets might look like. These planets are located near the star, TRAPPIST-1, 40 light years away. Or, 235 trillion miles. TRAPPIST-1 is named after the Transiting Planets and Planetesimals Small Telescope, located in Chile.

Since these planets are located outside of our solar system, they are considered exoplanets.

Exoplanets orbit a star other than the sun.

This is the largest system of multiple Earth-sized planets that orbit around the same star that has been discovered. In addition, three of the planets are in the habitable zone. NASA states that the habitable zone is “the area around the parent star where a rocky planet is most likely to have liquid water.” All seven planets have the potential for liquid water, though the odds are best for the three planets in the habitable zone.

This discovery follows the 2016 finding of three planets in the TRAPPIST system. With the Spitzer Space Telescope and several other ground-based telescopes, researchers could confirm the existence of two of the three planets and identified five new planets, making the grand total in this system seven planets. The Spitzer Space Telescope spent 500 hours observing TRAPPIST-1 in 2016, taking note of the planets in front of the host star to figure out the system architecture. With all the data collected, researchers can see the complex architecture of the system. It’s incredible that one telescope was making observations nonstop for 500 hours. That’s equivalent to roughly 3 weeks, or 21 days.

Sean Carey, manager of NASA’s Spitzer Science Center said that “this is the most exciting result I have seen in the 14 years of Spitzer operations.

So, next time you are outside at night, staring up at the black cloak that covers us, full of shimmering stars, remember that just a mere 40 light years away are seven exoplanets that are close enough for researchers to continue to collect data on and study.