NASA’s Kepler spacecraft has just found its largest single haul of planet discoveries, with 1,284 new bodies, more than doubling the recon mission’s burgeoning portfolio.
NASA’s suite of spacecraft capturing images of planets away in the distance is quite something, with Hubble’s immense picture catalogue, Cassini’s soon-to-be-ending solar system mapping and Kepler’s relentless discovery of new planets.
Kepler’s getting so good that, last summer, it spotted 4,302 potential planets, 1,284 have since been confirmed, with a similar number ‘more likely than not’ to be planets.
What does it mean? Well, it brings to Kepler’s total haul of discovered planets to 2,325, of the 3,200 known to science.
A whole new world
“Before the Kepler space telescope launched, we did not know whether exoplanets were rare or common in the galaxy,” said NASA’s Paul Hertz. Now, he said, astronomers think there could be more planets than stars – that’s quite something.
“This knowledge informs the future missions that are needed to take us ever-closer to finding out whether we are alone in the universe.”
550 of the new discoveries have the potential to be Earth-like rocky planets, based on their size. Nine of these orbit in their sun’s habitable zone, which is the distance from a star where orbiting planets can have surface temperatures that allow liquid water to pool.
With the addition of these nine, 21 exoplanets now are known to be members of this exclusive group.
Kepler was also the discoverer of Earth 2.0 last summer, the name Kepler-452b both honouring its discoverer and showing us how active the spacecraft is.
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.
Contenders on the scene
Earlier this month, a rare event occurred, in that potentially habitable planets were found in a non-Kepler scenario.
Astronomers have found three planets that may be habitable ‘just’ 40 light years away, orbiting an ultracool dwarf star called TRAPPIST-1.
Named after the telescope that astronomers are using to monitor its system (TRAnsiting Planets and PlanetesImals Small Telescope), TRAPPIST-1 is about one-eighth the size of our sun. It’s far weaker and radiates far less. However, that means the three planets orbiting it every 1.5, 2.4 and 73 days could support life.
Kepler has had a rocky 2016, shocking NASA workers when it suddenly went into ‘emergency mode’ for a couple of days. All was okay in the end, but it was a scary time for the space agency, as it highlighted the risk of losing one of its most successful space missions to date.
Exploding into a new mission
So successful, in fact, that it’s already on its second mission brief. The outer regions of planetary systems are K2’s new target, with peripheral bodies expected to pour in through Kepler’s lens from here on out. To do this, a technique called gravitational microlensing will be utilised.
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.
Earlier this year, Kepler captured the moment a star exploded, an exciting first for NASA.
However, the plethora of new planets is more exciting.
“They say not to count our chickens before they’re hatched, but that’s exactly what these results allow us to do based on probabilities that each egg (candidate) will hatch into a chick (bona fide planet),” said Natalie Batalha, co-author of the paper published on the findings.
“This work will help Kepler reach its full potential by yielding a deeper understanding of the number of stars that harbour potentially habitable, Earth-size planets – a number that’s needed to design future missions to search for habitable environments and living worlds.”