2nd LD: Scientists discover 7 earth-sized exoplanets around nearby star

A compact analogue of our inner solar system about 40 light years away from the Earth has been discovered, NASA announced during a press conference on Wednesday.

"The discovery gives us a hint that finding a second earth is not just a matter of if but when," Thomas Zurbuchen, associate administrator of the Science Mission Directorate said.

An international team of astronomers using powerful space telescopes and ground-based observatories have discovered the first known system of actually seven Earth-sized planets orbiting the nearby TRAPPIST-1, which is relatively close to us, in the constellation Aquarius.

And 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 discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system, according to NASA.

In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system.

Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, NASA's Spitzer Space 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.

"Looking for life elsewhere, this system is probably our best bet as of today," Brice-Olivier Demory, professor at the University of Bern's Center for Space and Habitability and one of the authors of the Nature paper, said in a statement. Endit