Kepler, the planet-hunting space telescope, is dead

3,000 potential exoplanets later, a failed reaction wheel means the end of the Kepler mission.

The Kepler telescope, a one tonne satellite launched in 2009 to scan for planets outside of our solar system, is dead.

Over the four years of its mission, the spacecraft has found over 3,000 stars which might have planets orbiting them, and the earth-based analysis has confirmed 134 planets orbiting 76 of them.

In April, the mission even announced the discovery of two potentially habitable planets. The two were roughly earth sized, and roughly earth temperature as well. Each of them might just lie in the "habitable zone", where liquid water can potentially exist.

Sadly, shortly after that discovery, Kepler ran into problems. The telescope manoeuvres through space with four reaction wheels, which keep it pointing in the right direction using a gyroscope effect. In July 2012, one of the wheels failed, but the mission was designed to only require three to accurately aim. In May this year, however, a second wheel failed. Yesterday, Nasa announced that they had given up trying to fix the wheels. Kepler can no longer be targeted accurately.

But, good news! Rumours of Kepler's death have been greatly exaggerated (by me, in paragraph one. Sorry.), because while the telescope can't be aimed any more, it's still useful. The imaging functionality works fine, and with two remaining reaction wheels and a limited amount of thruster fuel left it's even got a bit of manoeuvrability. NASA has opened it up to the community to work out the best way to make use of what's left working; one proposal, for instance, involves heavily post-processing the images to remove drift caused by the lack of a third wheel.

There's hope for the mission yet, which is great, because as Ars Technica's John Timmer writes, there's a lot more to learn:

A longer mission would identify planets further from their host stars. To identify a candidate, Kepler needs to see it pass between Earth and the star the exoplanet orbits three times. The further out a planet is, the longer one orbit takes, so the longer it will need to do three passes. As such, the existing data is heavily biased toward planets that orbit very close to their host stars; this also means that most of the potentially habitable planets we've spotted are orbiting dwarf stars, which are dim enough that water can remain liquid close in.

In other words, we simply haven't looked long enough to detect planets in a habitable zone around energetic stars. We have a much better picture of the diversity of exoplanets, but it's far from a complete one.

Kepler. Photograph: Wikimedia Commons

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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Why did Julian Assange lose his internet connection?

Rumours of paedophilia have obscured the real reason the WikiLeaks founder has been cut off from the internet. 

In the most newsworthy example of "My house, my rules" this year, Julian Assange's dad (the Ecuadorian embassy in London) has cut off his internet because he's been a bad boy. 

Rumours that the WikiLeaks' founder was WiFi-less were confirmed by Ecuador's foreign ministry late last night, which released a statement saying it has "temporarily restricted access to part of its communications systems in its UK Embassy" where Assange has been granted asylum for the last four years. 

Claims that the embassy disconnected Assange because he had sent sexually explicit messages to an eight-year-old girl —first reported by the US political blog Daily Kos — have been quashed. Wikileaks responded by denying the claims on Twitter, as Ecuador explained the move was taken to prevent Assange's interference with the US election. The decision follows the publication of leaked emails from Hillary Clinton's campaign adviser John Podesta, as well as emails from the Democratic National Committee (DNC), by WikiLeaks.

Ecuador "respects the principle of non-intervention in the internal affairs of other states," read the statement, though the embassy have confirmed they will continue to grant Assange asylum. 

Assange first arrived at the Ecuadorian embassy in London in June 2012, after being sought for questioning in Sweden over an allegation of rape, which he denies. WikiLeaks claims this new accusation is a further attempt to frame Assange.  "An unknown entity posing as an internet dating agency prepared an elaborate plot to falsely claim that Julian Assange received US$1M from the Russian government and a second plot to frame him sexually molesting an eight year old girl," reads a news story on the official site.

It is unclear when Assange will be reconnected, although it will presumably be after the US presidential election on 8 November.

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