Lead author Andy Weir’s own lunar rover may be a useful tool to survey Earth-like exoplanets
Last year’s Exoplanet Insight mission was especially successful in its aim to identify Earth-like exoplanets orbiting nearby stars. In the coming year, scientists will continue this work by training their telescopes on larger and more distant stars.
But in the new scientific era of exoplanet-hunting, humanity needs a new planet-sensing framework that is better suited to discovering tiny, rocky planets, the team of scientists from NASA’s Goddard Space Flight Center wrote in a study published on Tuesday in the journal Science Advances.
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Planets that have different compositions and atmospheres tend to orbit much closer to their stars, making it harder to do detailed surveys of them. Faraway, sun-like stars are much easier to observe.
Goddard’s postdoctoral research fellow Christina Boyle and her team wondered whether the James Webb Space Telescope (JWST), which is scheduled to launch in 2020 and replace Hubble in 2018, could change that, by finding small, rocky planets that are unusual in the region where they are expected to live.
The team used an example from the book The Martian, in which Matt Damon’s astronaut deals with erratic weather on a Mars that lacks water by collecting “rafts” of rainwater collected from melting Martian ice that Webb should be able to pick up.
In the case of Webb, Boyle’s team reckoned the space telescope’s 80-million-year-old reflectivity of the mirror, believed to be over 90%, would be good enough to capture the water reflected off the snow.
It might seem like too small a sample to find much, but there’s a lot that could be learned from even a tiny fraction.
Lead author Andy Weir, who also wrote The Martian, said he was asked by one of the astronomers to provide input on whether Earth-like planets were common in the universe, and if they had been randomly flitting around our galaxy in search of faraway targets.
“You may well be collecting images of these,” Weir said. “You’ll have rain cascading off a body of water and any of that water being frozen is reflective of light.”
And solar panels are highly reflective and have a near perfect reflectivity that will help the telescope capture certain wavelengths of light, Weir said.
“It’s easily possible if you move the end of the day during a sunless night, those red-giant stars might not be in focus. Even if you take a balanced view, it’s really easy to capture some of that spectrum,” he said.