In terms of the search for life on other planets, O'Neil says it might be hard to analyze a rock sample from the recently-discovered planets orbiting TRAPPIST-1, 39 light-years away. However, he says it should help narrow down the search for life on Mars to regions where water once covered the planet's surface.
"Instead of searching the whole planet of Mars, you can target these specific areas," he said, adding that Earth and Mars were "probably very similar" 4.3 billion years ago.
"I wouldn't be surprised to have these type of environments preserved on Mars as well," he said. "This is where life started on Earth… so let's look for them on Mars."