Kepler mission announces two exoplanets in the habitable "zone"

The planets are the right temperature and size to support liquid water.

The Kepler mission, a NASA project to find and profile planets outside of our solar system, has announced the discovery of two potentially habitable exosolar planets.

The planets are part of a system, Kepler-62, which is thought to contain five roughly earth-sized planets. The biggest is almost twice earth's size; the smallest slightly more than half.

That alone is notable, because the normal way the Kepler mission identifies planets is by measuring the gravitational they exert on their star. A big enough planet will pull the star slightly closer to the earth when it's on one side, and slightly further when it's on the other. That causes a minute fluctuation in the brightness of the star, measured from our planet, which the Kepler orbital observatory can sense.

But only the largest gas giants have such an effect, and while they are noteworthy finds in themselves, they aren't habitable. To find smaller planets, the mission looks at stars which have other fluctuations in light – due to planets passing in front of them. They then have to model every possible reason why those fluctuations could occur, and hope that they find that the most likely cause is exoplanets traversing the star.

The planets which they've found this way aren't just earth sized, though. Two of them, each measuring around 1.5 times the size of earth, are roughly the same distance away from their star as we are. Their orbits take a third and two thirds of an earth year each, but, because their star is less bright than our sun, they receive 1.2 and 0.4 times the light, respectively, that we do.

That will equal one hot planet and one cold one – but either of them might be in the so-called "habitable zone", where liquid water can exist. And liquid water is the only universal prerequisite we know for life.

The authors note that their method cannot tell if the planets are even rocky, as opposed to gas giants, let alone whether they actually have an atmosphere or water. But they are some of the best candidates we've found to date.

And crucially, we've found them fast. The Kepler telescope has been in orbit for around half its expected life, but it's already produced a vast amount of data to crunch. It's discovered almost 3,000 possible exoplanets, and has already found one that could have water. If the hit rate stays high, there could be many more.

Johannes Kepler, the 16th century astronomer for NASA's mission is named. Image: Hulton Archive/Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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"Death to all Jews": Why Disney dropped YouTube's biggest star PewDiePie

The Minecraft vlogger turned internet celebrity's taste for shock comedy was too much for the family-focused corporation. 

Disney has cut ties with YouTube’s most-subscribed star after he paid two Sri Lankan men five dollars to hold up a sign that read “DEATH TO ALL JEWS”.

Feel free to read that sentence again, it’s not going anywhere.

A still from PewDiePie's video, via YouTube

PewDiePie, real name Felix Kjellberg, has over 53 million subscribers on YouTube, where his videos about gaming earned him over $15m last year. The 27-year-old, whose content is popular with children, came under fire this month after the Wall Street Journal investigated anti-Semitic comments in his videos. In one video, a man dressed as Jesus says “Hitler did absolutely nothing wrong”, while in another Kjellberg used freelance marketplace Fiverr to pay two men to hold up the offensive sign. The videos have since been deleted.

Jumpcut.

The Walt Disney Company became affiliated with PewDiePie after they bought Maker Studios, a network of YouTube stars, for nearly $1bn in 2014. Following the WSJ’s investigation, Maker dropped the star, stating: “Although Felix has created a following by being provocative and irreverent, he clearly went too far in this case and the resulting videos are inappropriate. Maker Studios has made the decision to end our affiliation with him going forward.”

When you sack a YouTube Star, makes no difference who they are.

Via Wall Street Journal

But why should the story stop there? Neo-nazi website The Daily Stormer are now defending PewDiePie, while the notoriously politically-incorrect 4Chan forum /pol/ have called him “our guy”.  

In his defence, Kjellberg wrote a blog post denying an affiliation with anti-Semitic groups and explained his actions, writing: “I was trying to show how crazy the modern world is, specifically some of the services available online.” In a video last December the star also said: "It's extremely annoying how I can't make jokes on my channel without anyone quoting it as actual facts, like something I actually said", before dressing as a soldier and listening to one of Hitler's speeches while smiling. 

Pause.

(If all of this sounds familiar, recall when disgraced YouTuber Sam Pepper claimed a video in which he groped unsuspecting females was a “social experiment”).

Play.

And yet the story still isn’t over. Disney have learned a hard lesson about assuming that YouTubers are the squeaky clean fairy-tale princes and princesses they often appear to be. Shay Butler, one of the original founders of Maker Studios, yesterday quit the internet after it was alleged he sent sexual messages to a cam girl via Twitter.

Butler is one of the original "family vloggers", and has spent nine years uploading daily videos of his five children to YouTube. A practicing Mormon, Butler has become emblematic of family values on the site. “My heart is sick,” he wrote on Twitter, neither confirming nor denying the allegations of his infidelity, “I have struggled with alcoholism for years… My purpose is to rehab.” 

The result is a very dark day for YouTube, which has now dropped Kjellberg from its premier advertising network, Google Preferred, and cancelled the second series of the star's reality show, Scare PewDiePie

Amelia Tait is a technology and digital culture writer at the New Statesman.