Last month, the Gemini and Keck Observatories confirmed Kepler-186f to be the closest thing we have found to Earth’s twin.
This exoplanet — a planet orbiting another star — is in the habitable zone of its solar system, Kepler-186. It is roughly the same size as earth and is just one of 962 confirmed planets discovered by Kepler.
There are a couple thousand confirmed exoplanets and countless other unconfirmed ones. While this information is remarkable, our ability to search out and locate these exoplanets is relatively new and this discovery is going to seem insignificant and rudimentary in no time.
The size of Kepler-186f is known to be less than ten percent larger than Earth, but its mass, density and composition are not known. Previous research suggests that a planet the size of Kepler-186f is likely to be rocky. Prior to this discovery, the “record holder” for the most “Earth-like” planet went to Kepler-62f, which is 40 percent larger than the size of Earth and orbits in its star’s habitable zone. Kepler-186f orbits its star once every 130 days and receives one-third the energy that Earth does from the sun, placing it near the outer edge of the habitable zone. If you could stand on the surface of Kepler-186f, the brightness of its star at high noon would appear as bright as our sun is about an hour before sunset on Earth.
The star that it orbits is a red dwarf, as opposed to the sun, which is a yellow dwarf. In other words, it is lower in mass and cooler in temperature. Per Science Magazine, “The intensity and spectrum of the star’s radiation place Kepler-186f in the stellar habitable zone, implying that if Kepler-186f has an Earth-like atmosphere and water at its surface, then some of this water is likely to be in liquid form.”
In many ways, this is an exciting discovery. It gives hope to finding another planet in the galaxy that mimics the conditions necessary to sustain life as we know it.
Even if Kepler-186f turned out to be like Earth, there’s no guarantee that it is actually habitable. Furthermore, if you were to travel 186,000 miles per second — or the speed of light — it would take you nearly five centuries to get there. Hop on your average space shuttle and you might average 17,500 miles per hour. To date, our species has not existed as long as it would take to reach the exoplanet from here.
At present, we have observed about 46-47 billion light away. In that space, it is estimated that there are up to 500 billion galaxies out there and more stars than anyone could possibly fathom. The continually expanding universe is impossible for us, at this juncture, to accurately measure.
This handy Scale of the Universe site gives a good visual aide to put things in perspective.
Given the number of galaxies, stars, and exoplanets out there, the pure numbers would show that there are plenty of places in which life could exists elsewhere in the universe. Life certainly does exist elsewhere too, though it likely differs vastly from our definition of it. To think otherwise would be shortsighted.
“This is really a tip-of-the-iceberg discovery,” said astronomer Jason Rowe to the LA Times. They’re still looking for more in the Kepler data — but after finding the planet known as Kepler-186f, “we can infer that other ones are likely to exist. And that’s going to be the job of future missions to find [them].”
If NASA figures out how to bend space-time with their Warp Drive concept or we learn how to master and traverse black holes without getting torn to shreds, maybe we could make our way onto one of these theoretical distant planets in the future and call it home.
From my personal perspective, such efforts are futile. We are born to die. We came into existence to become extinct. No matter what we try, nature will catch up to us eventually.
So, I discourage you from looking at the discoveries from Hubble, the rovers, and many of the other brilliant technologies our species has created as a way to get off our planet (which is not to say that we should not visit other planets). Rather, I encourage you to absorb this information and use it as a way to learn about ourselves, our planet and our place in the universe.