A regular day quickly turned historic, courtesy a breakthrough announcement by the National Aeronautics and Space Administration (NASA). Scientists working with telescopes at the European Southern Observatory announced the existence of an entire system of Earth-sized planets. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
The team also confirmed that the density measurements of the planets indicate that the six innermost are Earth-like rocky worlds. Thomas Zurbuchen, associate administrator for the agency’s Science Mission Directorate in Washington, in an official report to the NASA, said,
This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life. Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.
According to a report by Futurism.com, three of the 7 planets lie in the star’s habitable zone. This means that all three of these alien worlds may have entire oceans of water, dramatically increasing the possibility of life. The other planets are less likely to host oceans of water, but the team states that liquid water is still a possibility on each of these worlds.
According to the NASA report, at about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.
The exoplanet system is also called the TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. Almost a year ago, they had confirmed the existence of three planets in the system, which, with the assistance of the European Southern Observatory's Very Large Telescope, confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated — scientists believe it could be an icy, "snowball-like" world, but further observations are needed.