NASA scientists revealed an extraordinary new discovery during a press conference today, seven rocky, Earth-sized planets orbiting a single star.

Three out of the seven planets are situated at the ideal distance from the sun to theoretically harbor liquid water, which makes them potentially habitable for life as we know it.

New solar system:

This is the highest number of planets located in the habitable zone ever discovered around a single star outside our solar system.

It’s important to understand that just because these planets could possibly contain liquid water, it doesn’t mean that they do. However, the likelihood is bigger given their location.

The planets are located about 40 light years (or 235 trillion miles) from Earth in the Aquarius constellation, they are orbiting an ultra-cool dwarf star called TRAPPIST-1

The system is named after the Transiting Planets and Planetesimals Small Telescope (TRAPPIST), located in an observatory in Chile. TRAPPIST researchers announced in May 2016 that they have discovered three planets in the system. NASA’s Spitzer Space Telescope confirmed the existence of those exoplanets as well as four additional planets.

The planets:

The TRAPPIST-1 system has a very different habitable zone from our systems, making it especially interesting.

TRAPPIST-1’s star is much cooler than our sun, and the planets are much closer to the sun than Earth could potentially have liquid water, all seven of TRAPPIST-1’s planets are closer to the star than Mercury is to our own sun. Also, each of the planets are so close to one another they would show in one another’s skies similar to how the moon appears in ours.

The planets may be tidally locked, according to NASA scientists’ speculations, meaning that the same side of the planet is always facing the star, causing one half of the planet to be in permanent daylight and the other in perpetual night.

This could cause weather patterns different than anything we’ve ever seen before on Earth, and extreme differences in temperature from one side to the other

The Spitzer telescope detected the presence of the planets through observing the infrared wavelengths emitted by the star over a period of 500 hours, each time a planet passed in front of the star, the telescope detected changes in the star’s brightness, this was followed up by a study NASA conducted using the Hubble Space Telescope to determine whether the planets were rocky, or likely had an inflated atmosphere similar to our system’s gas planets.

The Kepler space telescope is recording observations about the system, which will reveal more properties about the exoplanets in March.

NASA’s new James Webb Telescope, which will launch in 2018, will also be pointed toward TRAPPIST-1 to analyze the planets’ temperature, surface pressure, and atmospheric makeup – all key factors that will reveal whether these worlds can actually sustain life.