NASA’s Potential for Alien Life, Kepler-452b: Earth 2.0?
Most stars have planetary systems. In astronomy, this is new information. Many stars are not bright enough to support life, at least according to current science, but we do now know that small, rocky planets like Earth are the rule, not the exception throughout the solar system, raising the possibility of human space colonization by several fold.
NASA announced today some new discoveries about planets in the solar system, and specifically in the constellation Cygnus. They now know more about an exoplanet they’re calling Kepler-452b, which is about 1400 light-years away from Earth, and orbits its sun only slightly slower than our planet. It has twice our gravity and five times the mass, but scientists say that humans could likely adapt to these conditions. “It might be quite challenging at first,” said Jon Jenkins, lead data analyst for the Kepler project.
“Gravity really sucks,” said former astronaut John Grunsfeld. He added that we have similar situations when we carry a lot of gear, such as soldiers, firefighters, hikers. It is fairly easy to simulate 2x gravity, by adding the same amount you weigh to your body.
The reason that scientists believe there could be life on Kepler is that it has spent 6 billion years in the “habitable zone” of its orbit, meaning that life could have begun long, long before it did here. This is barring any future changes to our understanding of what constitutes the conditions for life, and scientists were sure to mention that there is currently a raging debate as to whether we have the capability to identify signs of life adequately or not.
The most common type of planets are small, rocky planets like Earth, and about 10-25% of stars have them. Large planets like Jupiter are the exception, according to the SETI Institute‘s Jeff Coughlin.
Are there suns like our own, with planets like our earth around them? Well, Kepler was specifically designed to try and answer the question of, are there solar systems around other stars, which is definitively answered – we see solar systems like crazy. And to try and answer the question of, are there rocky planets, earth sized, in the habitable zone, where liquid water can exist, orbiting other stars?
Now, Kepler does that in a really somewhat incredible way. If you’ve seen the eclipse of the moon, for instance, you know that the moon can block out the light from the sun and make it dark temporarily. Well, when a planet goes between its star and the Earth, it dims a tiny amount of the light, just like that eclipse.
Over 4,500 Confirmed Planets
Over 500 new candidates were added to Kepler’s discoveries for its 7th release, bringing the total planets discovered during the Kepler “data collection phase” to more than 4,500. Of this, a very small number are near enough to their sun to be habitable. Coughlin believed this was impressive because it only came about as a result of one extra month of data, indicating significant improvement in NASA’s planet-hunting. To be clear, the planets were not uncovered as a result of continued data collection, but improved processing techniques.
Of all these, Kepler is unique in some crucial ways. First and foremost, its orbit is roughly the same as Earth’s orbit, 365 days. It is larger and thus has much stronger gravity, but as mentioned before, scientists believe humans could adapt. There are other planets much like Earth which just don’t have the proper galactic properties, mostly because the stars they are orbiting are too small to promote life.
Jon Jenkins explained why the confirmation of Kepler-452b is important:
Today, we add the first small, possibly rocky planet orbiting a G star. It has the same size orbit as the earth, and the same length year. It orbits the same type and temperature star and has a better than even chance of being rocky. It’s a real privilege to be able to deliver this news to you today. […]
We’ve worked really hard over the last several years to improve our planet-hunting software and we’re seeing the results in this discovery. Now given that every small habitable zone planet we detect corresponds to at least 50 that we can’t see in our data because they’re not aligned right, or we’re not quite sensitive enough to see them, we can say that near-Earth sized planets in the habitable zone of sun-like stars are common throughout the galaxy. Surely, there are more gems like 452b waiting to be discovered.
A satellite will be launched in 2017 to explore as to “if they might have conditions that will be conducive to future generations.” It could be centuries before Earthlings meet life from other parts of the universe. If nothing else, the notion of Earth’s being a unique planet in the grand scheme of things is rapidly dissipating thanks to the research of the Kepler project. As Jenkins told a reporter during the follow-up, “We need to do work to study these planets and confirm them as planets.”
Images from Shutterstock and Nasa.