What On Earth Is An Earth-Like Planet?

Nobody has yet disproven that the Earth is indeed the only unique planet that supports life. But since humans are threatened by a potential extinction, scientists have been obsessed about finding another planet like ours.

But what really is an Earth-like planet? Space.com explained that in order for a planet to be habitable like Earth, it has to be located in a habitable zone of its orbiting star, which means it should not be too far like planets Saturn and Jupiter or too close like Mercury and Venus from the Sun. The planet should also have a rocky surface, could hold liquid water and has a size about 0.5 to 1.5 times the Earth's.

However, another scientist detailed the specific requirements a planet should have in order for it to support human life. According to astrophysicist Dr. Hugh Ross, Ph.D., at the University of Toronto, the planet must pass in the evaluation of having eight more habitable zones aside from liquid water such as tidal, photosynthetic, ultraviolet, ozone, obliquity, rotation rate, astrosphere and atmospheric electric fields.

According to Dr. Ross, Earth is the only planet that has passed on this evaluation so far. But why do scientists spend most of their time looking for another habitable planet and alien life to prove it?

"They are all too aware that the window of time for the existence of advanced life on Earth is rapidly coming to a close," Dr. Ross explained. "They are convinced that the only hope for humanity is to find another planet in another planetary system that we humans can colonize."

This could refer to Stephen Hawking's theory about the Earth's extinction in the next 2,000 years.

Since 2009, NASA has launched its Kepler Space Telescope that confirmed the existence of over 2,000 planets outside the Solar System including the 1,284 exoplanets that were confirmed this year.