Kepler Mission: The Youngest Exoplanet Ever Discovered, K2-33b

Scientists have discovered the youngest exoplanet so far, Kepler K2-33b, which is just 5 to 10 million years old. That might seem like a while, but compared to Earth’s age of 4.5 billion years, give or take a few million, the new planet is just an infant. That’s important for scientists, who still struggle to understand the process in which planets are formed.

Co-author of a paper on the new exoplanet Erik Petigura of Caltech explained.

“The newborn planet will help us better understand how planets form, which is important for understanding the processes that led to the formation of Earth.”

According to NASA, K2-33b is a little bit larger than Neptune, and its orbit around its star is just 5 to 10 days. That means it’s incredibly close, which challenges a few theories.

NASA has discovered about 3,000 exoplanets so far thanks in large part to the Kepler mission, but most are like Earth in that they are middle-aged. That leaves scientists guessing about what early planet formation is really like, or as NASA put it, it’s like trying to understand babies by studying adults. That leaves plenty of mysteries. One that baffles scientists is how large planets like K2-33b get so close to their stars.

One theory suggested that it takes hundreds of millions of years for big planets to migrate to such a short orbit, but the approximately 10 million-year-old K2-33b refutes that idea.

Another process called “disc migration” might have only taken hundreds of thousands of years, and so that might explain Kepler’s K2-33b. The other theory is that it just formed “in situ,” about where it is right now.

Trevor David of Caltech, lead author of the paper, says in situ used to be a radical idea.

“After the first discoveries of massive exoplanets on close orbits about 20 years ago, it was immediately suggested that they could absolutely not have formed there, but in the past several years, some momentum has grown for in situ formation theories, so the idea is not as wild as it once seemed.”

Exoplanets like K2-33b will probably be the subject of debate for the foreseeable future. Data from NASA’s Spitzer Space Telescope shows the world is still surrounded by a protoplanetary disk of gas and dust. Scientists first saw Kepler’s K2-33b dimming its star’s light to us by passing in front of it during orbit. That method of detection has led to the majority of NASA’s 3437 discovered exoplanets.

The new exoplanet is the most recent record-setting find of the Kepler mission. NASA has been surveying planets and has found other astounding specimens, including an exoplanet so large it shouldn’t be able to exist according to Space.com.

As previously reported by The Inquisitr, exoplanet 55 Cancri e, a planet with a mass much larger than the Earth, could have vaporized rock in its atmosphere and oceans of lava that flow like water. That planet also has an extremely close orbit, although it’s not near the size of K2-33b. It reaches maximum temperatures of over 2,000 degree C, although it drops over a thousand degrees on the side not facing the star.

Kepler-452b being compared to a correctly scaled image of Earth. The exoplanet is clearly large, but it's still one of the most similar planets ever found. Kepler-452b being compared to a correctly scaled image of Earth. The exoplanet is clearly large, but it’s still one of the most similar planets ever found. [Image via NASA/JPL-Caltech/T. Pyle]That planet is also a mystery, but the biggest goal for the Kepler and K2 missions is to find worlds like Earth, exoplanets that might host other lifeforms. The exoplanet Kepler-452b was the first close match. It’s about six billion years old and the correct distance from its star for liquid water. It also has a diameter roughly 10 percent larger than the Earth’s and has a 385-day year.

K2-33b is the youngest exoplanet from the Kepler mission, but it’s just one in a long list of extraordinary worlds discovered.

[Image via NASA/JPL-Caltech]