And there are expectations for microbial life, similar to Earth's bacteria, to be even more widely spread throughout space than intelligent life.But bacteria can't send us radio signals. "We need to develop new technologies to discover them at a distance," Vakoch said. "As the next generation of space telescopes is launched, we will increase our chances of detecting signs of life through changes to the atmospheres of planets that orbit other stars, giving us millions of targets in our search for even simple life in the cosmos."By the end of 2020, we'll be within a few months of the much-awaited launch of NASA's James Webb Space Telescope, Vakoch said, which will be able to study the atmospheres of exoplanets for potential signs of life. But it could take much longer, until after the launch of the European Space Agency's Atmospheric Remote-sensing Infrared Exoplanet Large-survey, or ARIEL, in 2028, before we have "definitive proof" of extraterrestrial microbes through telltale alterations in the atmospheres of exoplanets, Vakoch said.