Kepler, one of NASA’s most successful missions, has not been reached in a week, with worries that the prized space telescope is on its last legs.
Exactly one month ago, NASA wrote of how happy it was with Kepler, deep into its second age in the K2 planet-finding mission.
Happy March, sad April
“The spacecraft has operated beautifully, with scarcely a whiff of trouble,” said Charlie Sobeck , Kepler and K2 mission manager, noting how NASA had “taken on a bit more risk” to get better shots of planets immense distances from Earth.
Fast forward four weeks and Sobeck is worried. At some stage after Kepler was turned around to face the centre of our Milky Way, it entered a “fuel intensive” emergency mode.
The mission has declared a spacecraft emergency, which provides priority access to ground-based communications at the agency’s Deep Space Network.
Almost 75m miles from Earth, getting information to and from Kepler is a slow process, with 13 minutes the time it takes to send data in one direction.
The last regular contact with the spacecraft was on 4 April, when there were no signs of trouble.
Earth 2.0
Kepler is a bit of a gem. Completing its primary mission as far back as 2012, finding 5,000 exoplanets (one-fifth of which have been confirmed) since it began its K2 mission in 2014.
If Kepler gently rings a bell in the recesses of your memory, it might be to do with Earth 2.0, the planet found last summer that is the closest to Earth in terms of orbit, heat, size and potential habitability.
Kepler-452b is in a solar system very similar to our own and is the right distance from its star to potentially be habitable. The planet is 6bn years old, 60pc larger than Earth and receives 10pc more energy from its star, which is 1.5bn years older and 20pc brighter than our sun, though has the same temperature.
When stars explode
Last month, Kepler captured the moment a star exploded, spotting the resulting shockwave (below) – this was an incredible first. It has even been used to discount alien conspiracies about megastructures on distant stars. But now it’s in quite a bit of trouble.
A few days ago, NASA pointed to the outer regions of planetary systems as K2’s new target, with peripheral bodies expected to pour in through Kepler’s lens from hear on out.
In the exoplanet detection toolkit, scientists have a technique well suited to search these farthest outreaches and the space in between the stars. This technique is called gravitational microlensing.
For this experiment, astronomers rely on the effect of a familiar fundamental force of nature to help detect the presence of these faraway worlds: gravity. The gravity of massive objects such as stars and planets produces a noticeable effect on other nearby objects.
“We now project that the spacecraft may have enough fuel to operate for nearly another three years!” said Sobeck last month. How times change.
*Update: Crisis averted!
Main image of planets via Shutterstock