This new video from our friends Tony Darnell and Scott Lewis focuses on the discoveries that the Kepler Space Telescope has made, which has opened up a whole new universe and a new way of looking at stars as potential homes for other planets. Only about 20 years ago, we didn’t know if there were any other planets around any other stars besides our own. But now we know we live in a galaxy that contains more planets than stars.
If you extrapolate that number to the rest of the Universe, it’s mind-blowing. According to astronomers, there are probably more than 170 billion galaxies in the observable Universe, stretching out into a region of space 13.8 billion light-years away from us in all directions.
And so, if you multiply the number of stars in our galaxy by the number of galaxies in the Universe, you get approximately 1024 stars. That’s a 1 followed by twenty-four zeros, or a septillion stars.
However, it’s been calculated that the observable Universe is a bubble of space 47 billion years in all directions… or it could be much bigger, possibly infinite. It’s just that we can’t detect those stars because they’re outside the observable Universe.
For the first time, scientists have discovered an Earth-size alien planet in the habitable zone of its host star, an “Earth cousin” that just might have liquid water and the right conditions for life.
Image 1: This artist illustration shows what it might be like to stand on the surface of the planet Kepler-186f, the first-ever Earth-size planet to be found in the habitable zone of its star. Credit: Danielle Futselaa
Image 2: This artist illustration shows the planet Kepler-186f, the first Earth-size alien planet discovered in the habitable zone of its star. Credit: NASA Ames/SETI Institute/JPL-CalTech
The newfound planet, called Kepler-186f, was first spotted by NASA’s Kepler space telescope and circles a dim red dwarf star about 490 light-years from Earth. While the host star is dimmer than Earth’s sun and the planet is slightly bigger than Earth, the positioning of the alien world coupled with its size suggests that Kepler-186f could have water on its surface, scientists say. You can learn more about the amazing alien planet find in a video produced by Space.com.
"One of the things we’ve been looking for is maybe an Earth twin, which is an Earth-size planet in the habitable zone of a sunlike star," Tom Barclay, Kepler scientist and co-author of the new exoplanet research, told Space.com. "This [Kepler-186f] is an Earth-size planet in the habitable zone of a cooler star. So, while it’s not an Earth twin, it is perhaps an Earth cousin. It has similar characteristics, but a different parent."
Scientists think that Kepler-186f — the outermost of five planets found to be orbiting the star Kepler-186 — orbits at a distance of 32.5 million miles (52.4 million kilometers), theoretically within the habitable zone for a red dwarf.
Earth orbits the sun from an average distance of about 93 million miles (150 million km), but the sun is larger and brighter than the Kepler-186 star, meaning that the sun’s habitable zone begins farther out from the star by comparison to Kepler-186.
"This is the first definitive Earth-sized planet found in the habitable zone around another star," Elisa Quintana, of the SETI Institute and NASA’s Ames Research Center and the lead author of a new study detailing the findings, said in a statement.
Other planets of various sizes have been found in the habitable zones of their stars. However, Kepler-186f is the first alien planet this close to Earth in size found orbiting in that potentially life-supporting area of an extrasolar system, according to exoplanet scientists.