Is NASA searching for aliens on far-away planets?
Not quite, but scientists and astronauts alike are confident that life exists beyond planet Earth.
The Kepler space telescope, launched in 2009, enables NASA to see deeper into space than ever before, providing new insights about the existence of life elsewhere.
Scientists estimate, through Kepler-gleaned data, that almost every star in our galaxy is circled by at least one planet.
What we shouldn't expect to find, Massimino explained, are full-fledged, human-sized creatures.
Should evidence of life turn up on another planet, it will likely be "microbial, some small organism," Massimino said.
Potential size, however, isn't reason to discount the significance of finding other forms of life.
"That would be the greatest discovery ever," Massimino said.