The Transiting Exoplanet Survey Satellite, or TESS, of NASA, however, teams working on it discovered a few particularly intriguing planets that orbit in their parent stars' habitable zones in the summer of this year. One planet, which is 30% bigger than Earth and orbits its star in less than three days, is now in orbit. The other planet, which is 70% bigger than this one, may have a deep ocean.

The two exoplanets, which are smaller than ice giants like Neptune and Uranus but bigger than the Earth, are referred to as super-Earths.

In essence, scientists still believe that life is only capable of existing on Earth. Focusing the search for life on planets that resemble Earth in many ways, or 'Earth clones,' would seem to make sense. Nevertheless, a research has found that the best chance astronomers have of finding life on an extraterrestrial planet may be on a super-Earth similar to those recently discovered.

The majority of super-Earths are circling cool dwarf stars, which are lower mass and have longer lives than the sun.

To put it simply, there are hundreds of cool dwarf stars for every star like the Sun, and researchers have found super-Earths orbiting 40% of the cold dwarf stars they have studied.

Astronomers will look for biosignatures, or biological leftovers that can be found in a planet's atmosphere, to determine whether there is life on distant exoplanets.

The James Webb Space Telescope, which is outlined in a NASA report, wasn't designed to study exoplanets because they hadn't yet been discovered by scientists.

But it can perform some of this science, and in its first year of operation it will aim at two super-Earths that might be habitable.James Webb has a number of other super-Earths with large oceans that have been discovered in recent years, and the planets discovered this summer are also attractive candidates.

Over time, the climate has changed from ocean-boiling hot to deep-freeze cold due to tectonic activity and variations in the brightness of the sun on Earth.

For most of this planet's 4.5 billion year history, humans and other larger animals have been unable to live there.

Simulations have indicated that while it was a question of chance, Earth's long-term viability was not predetermined. Literally, it is a blessing that we are alive.