Three Earth-like planets have been recently discovered orbiting an ultracool dwarf star some 40 light years away, making them the best candidates found so far to have life.
A team of astronomers led by researchers from the Massachusetts Institute of Technology and Belgium's University of Liege found that the planets were comparable to Earth and Venus in size and temperature, according to
MIT News.
Details of the discovery were published in the latest issue of the science journal
Nature on Monday.
"These planets are so close, and their star so small, we can study their atmosphere and composition, and further down the road, which is within our generation, assess if they are actually inhabited," said MIT's Julien de Wit, the study's co-author. "All of these things are achievable, and within reach now. This is a jackpot for the field."
Scientists involved in the research used a Chile-based 60-centimeter telescope called TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope) to find the planets, noted MIT News. The telescope examined 60 nearby dwarf stars in an attempt to find planets orbiting them.
"As the three planets orbit, transiting in front of TRAPPIST-1 from the telescope's perspective, the star blinks and dims out of our view," said the
Washington Post. "Scientists use this dimming to calculate the size of the planets and their distance from their host star.
"Because planet composition is closely tied to these metrics, scientists can say with confidence whether a world is rocky, like Earth – as opposed to a massive planet composed of gas or ice – and whether it could host liquid water," said the Post.
Adam Burgasser, another co-author from the University of California, San Diego, told
CNN that two of the planets receive about four times the amount of radiation than Earth does from the sun, which suggests they are in the "habitable zone."
"Habitable zones" are the distance scientists believe planets must be from their stars where they could have water on the surface and the temperature to sustain life, noted CNN. Although less is known about the third planet, researchers believe it is in the zone as well.