Have you ever looked up at the night sky and wondered, “Are we truly alone in this universe?” If you are among those who “want to believe,” the good news is that new planets are being discovered with increasing frequency. So far, the total is some 3,700 planets orbiting distant stars. But it is still unclear whether any of them can support life. Plenty of scientists are on the case.
Dr. Adrian Lenardic teaches planetary geophysics at Rice University, and is part of a group of scientists commissioned by NASA to advance the search for life beyond Earth. Some of his recent research has challenged the notion that planets require plate tectonics to support life.
“We know that life requires energy, and for a long time we’ve thought that energy from the star is critical, but there’s also energy from the interior of the planet,” Lenardic says. “That energy can manifest itself in different ways, and it need not be plate tectonics.”
Essentially, this planetary energy that fosters life doesn’t need to look the way it does on Earth, which creates interior energy from shifting continents, volcanoes, i.e., plate tectonics. Instead, the energy can come from volcanic energy, mountain creation, and other geologic activity without doing it the same way Earth does it. According to Lenardic, what is most important is not the presence of plate tectonics but the presence of liquid water.
“From the theoretical side, there has been work to ask, ‘could those types of geologic activity allow for the conditions that are conducive to life as we know it?’” Lenardic says. “More specifically, ‘could they actually maintain conditions that allow liquid water to exist over long time scales?’”
Liquid water is vital not only to life itself, but the search for it as well. With future generations of telescopes, Lenardic hopes that scientists will be able to detect signals that indicate the presence of liquid water. With telescope technology as it stands now, and as he expects it to advance, Lenardic remains cautiously optimistic about the discovery of extraterrestrial life in the near future.
“I can’t really make any bets; it’s going to depend on the next generations of telescopes that come in,” Lenardic says. “But again, being an optimist, within two generations of telescopes–maybe 50 years?”