"The genesis of life is as inevitable as the formation of atoms ... Life exists on other planets and we will find it within 20 years," he said, according to the Interfax news agency.
Speaking at an international forum dedicated to the search for extraterrestrial life, Finkelstein believes that aliens will look like earthlings: they will have two legs, two arms and a head. "Possibly, they will have a different color skin, but the same happens here. While we have been searching for extraterrestrial civilians, we have been waiting for messages from space, not the other way," he said.
About 1,000 exoplanets, i.e. planets circling around stars like the Sun, have been found, and 10% of them resemble the Earth, researchers said. There will be life on such planets if there is water.
"The whole time we have been searching for extraterrestrial civilizations, we have mainly been waiting for messages from space and not the other way," he said.
In March a Nasa scientist caused controversy after claiming to have found tiny fossils of alien bugs inside meteorites that landed on Earth.
Richard Hoover, an astrobiologist at the US space agency's Marshall space flight centre in Alabama, said filaments and other structures in rare meteorites appear to be microscopic fossils of extraterrestrial beings that resemble algae known as cyanobacteria.
Writing in the Journal of Cosmology, Hoover claimed that the lack of nitrogen in the samples, which is essential for life on Earth, indicated they are "the remains of extraterrestrial life forms that grew on the parent bodies of the meteorites when liquid water was present, long before the meteorites entered the Earth's atmosphere."