NASA’s Jet Propulsion Laboratory is developing what has to be the most stylish spacecraft ever – a giant sunflower-shaped starshade that will someday block out star light so that a telescope behind it can better search for exoplanets similar in size and composition to Earth.
At the recent TED2014 conference in Vancouver, Canada, Princeton University astronomer Jeremy Kasdin presented the challenge conventional telescopes face in looking for exoplanets and the elegant solution the starshade would provide. While we can currently detect the presence of exoplanets, Kasdin pointed out that the bright light of nearby stars makes them nearly impossible to see.
A starshade mission would allow us to directly image Earth-size, rocky exoplanets, which is something we can’t do from the ground.
In 1952, astronomer Lyman Spitzer (namesake of the Spitzer Space Telescope) proposed creating an artificial eclipse to block the star but not the exoplanet. A flat screen wouldn’t work because light can bend around it, so Spitzer designed a starshade in the shape of a flower with pointed petals to deflect the light away from the telescope behind it. With the light blocked, the telescope does not need to be as powerful as the Hubble.
Kasdin and engineers at JPL are now dealing with the challenges of making this work. The shade and the telescope can be launched together. Once separated, robots will deploy and position the half-a-football-field-sized starshade. Other robots will move and position the telescope 50,000 km (31,000 miles) behind the shape. The telescope can be multifunctional, allowing astronomers in other specialties to use it.
The estimated $1 billion three-year mission is still in the modeling stage but the interest is building, especially with the possibility finding an exoplanet that can support life. As Kasdin describes it:
We’ll be able to show people a picture of a dot and explain that that’s another Earth.
Not to mention showing them one fine-looking starshade.