The latest findings from NASA’s Kepler mission are in. The first near-Earth-size planet has been discovered around a sun-like star. Kepler-452b marks a milestone for the Kepler program. It’s the smallest planet yet discovered orbiting in the habitable zone of a G2-type star (like our sun).
“On the 20th anniversary year of the discovery that proved other suns host planets, the Kepler exoplanet explorer has discovered a planet and star which most closely resemble the Earth and our Sun,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate. “This exciting result brings us one step closer to finding an Earth 2.0.”
Here’s what NASA had to say about Kepler-452b today.
1) Kepler-452b has a diameter 60 percent larger than Earth’s and is classified as a super-Earth.
2) The Earth-like planet is located at just the right distance where liquid water could exist.
3) The small exoplanet sits 1,400 light-years away in the constellation Cygnus. Unless we start figuring out wormhole technology, we won’t be visiting Kepler-452b anytime soon.
4) Kepler-452b orbit is very similar to Earth’s. It takes the exoplanet 385 days to orbit its parent star.
5) Kepler-452b is also older than Earth. Its star, Kepler-452, is 6 billion years old. That’s about 1.5 billion years older than the sun. The exoplanet is believed to be about the same age.
“We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth’s evolving environment,” said Jon Jenkins, Kepler data analysis lead at NASA’s Ames Research Center. “It’s awe-inspiring to consider that this planet has spent 6 billion years in the habitable zone of its star; longer than Earth. That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”
6) SETI hasn’t detected a signal from the Kepler 452 system. Astronomers with the SETI Institute used the Allen Telescope Array in northern California to listen for signals. So far, nothing.
The Kepler team expands number of exoplanet candidates by 521
Kepler-452b wasn’t the only big news today. Kepler scientists expanded the number of potential planet candidates by 521. 12 of these candidates have diameters between one and two times that of our planet. Nine of them orbit stars with similar characteristics of our sun.
“We’ve been able to fully automate our process of identifying planet candidates, which means we can finally assess every transit signal in the entire Kepler dataset quickly and uniformly,” said Jeff Coughlin, Kepler scientist at the SETI Institute. “This gives astronomers a statistically sound population of planet candidates to accurately determine the number of small, possibly rocky planets like Earth in our Milky Way galaxy.”
Kepler has spotted more than 4,600 planet candidates. 1,030 have been confirmed.
The Kepler mission
Kepler is looking for worlds like Earth. The spacecraft is looking for terrestrial planets that range from one-half to about twice the size of Earth. Even better if there in the habitable zone of their parent stars.
But, how does it do it? Hubble couldn’t even take a decent picture of Pluto. What is Kepler’s secret?
It’s all about the stars. Kepler is on the lookout for transits, when a planet passes in front of its star. As this happens, the brightness of the star is affected slightly. Kepler is looking for these changes in brightness.
The video below shows what Kepler is looking for.
Once detected, scientists can determine the size of the planet’s orbit by looking at how long it takes to transit. The planet’s size can be calculated by how much the brightness of the star is affected and the size of the star.
Because Kepler has to continuously monitor these stars, it’s first phase looked at just a tiny portion of the sky.
More than 1,000 planets have been confirmed in this small portion of the sky. Imagine what else lies out there.
Image credits: NASA