Seven Earth-size planets have recently been discovered orbiting a nearby star. These planets in turn orbit a dwarf star known as Trappist-1, residing roughly 40 light-years (235 trillion miles!) from Earth. Being so close in proximity (in cosmic terms), it allows for the planets to be studied quite intensely.

“This is the first time so many planets of this kind are found around the same star,” Michael Gillon, an astronomer at the University of Liege in Belgium and the leader of an international team that has been observing Trappist-1, said during a conference organized by the journal Nature, which is responsible for publishing the findings.

“I think that we have made a crucial step toward finding if there is life out there,” said Amaury H. M. J. Triaud, an astronomer at the University of Cambridge and another member of the research team. “Here, if life managed to thrive and releases gases similar to that we have on Earth, then we will know.”

“You can just imagine how many worlds are out there that have a shot to becoming a habitable ecosystem,” said Thomas Zurbuchen, associate administrator of NASA’s science mission directorate, during a NASA news conference on Wednesday. “Are we alone out there? We’re making a step forward with this towards answering that question.”

Scheduled to launch next year, the James Webb Space Telescope will peer at the infrared wavelengths of light, ideal for studying Trappist-1. Both telescopes on ground and the Hubble Space Telescope in orbit will also be able to discern some of the molecules in the planetary atmospheres. Trappist planets are comparable to the size of earth, but the star is quite different than the Sun. In fact, according to Dr. Gillon, if our sun were the size of a basketball, Trappist-1 would be a golf ball. Also, upon observing Trappist-1 almost non-stop for 20 days, scientists were then able to distinguish seven planets, although the planets are too small and too close to the star to be photographed directly.

“They form a very compact system,” Dr. Gillon disclosed, “the planets being pulled close to each other and very close to the star.” In addition, because these planets are so close to the star, their surfaces could be capable of water flow, of course a necessary ingredient for life. It has been confirmed that two of the innermost planets are not enveloped in hydrogen, meaning they are rocky like Earth. Now NASA scientists must find out if oxygen is in any of the planet’s atmosphere. This “would tell us that there is life with 99 percent confidence,” Dr. Gillon insisted.

“If you’re looking for complex biology, intelligent aliens that might take a long time to evolve from pond scum, older could be better,” Dr. Shostak said. “It seems a good bet that the majority of clever beings populating the universe look up to see a dim, reddish sun hanging in their sky. And at least they wouldn’t have to worry about sun block.”