Lately, a handful of new discoveries make it seem more likely that we are not alone - that there is life somewhere else in the universe.
In the past several days, scientists have reported there are three times as many stars as they previously thought. Another group of researchers discovered a microbe can live on arsenic, expanding our understanding of how life can thrive under the harshest environments. And earlier this year, astronomers for the first time said they'd found a potentially habitable planet.
"The evidence is just getting stronger and stronger," said Carl Pilcher, director of NASA's Astrobiology Institute, which studies the origins, evolution and possibilities of life in the universe. "I think anybody looking at this evidence is going to say, 'There's got to be life out there.'"
A caveat: Since much of this research is new, scientists are still debating how solid the conclusions are.
Another reason to not get too excited is that the search for life starts small - microscopically small - and then looks to evolution for more. The first signs of life elsewhere are more likely to be closer to slime mold than to ET. It can evolve from there.