A New Experimental Coronagraph Is Approved for Exoplanet Hunting

NASA has announced that the WFIRST (WideField Infrared Survey Telescope), its next generation exoplanet hunting space telescope, will include a revolutionary new coronagraph that will make it possible to examine far-flung worlds in unprecedented detail.

While space appears to be a dark place to most observers, planet hunting astronomers hold an entirely different view. With billions of stars emitting light across the galaxy, the search for faint exoplanet signatures can be difficult if those targeted worlds are being masked by ambient stellar light. To reduce the number of extraneous lumens entering a space telescope’s sensors, engineers develop coronagraphs, light blocking instruments that can bring greater contrast to deep space images.

But NASA’s engineers have never developed a coronagraph this sophisticated before.

“What we’re trying to do is cancel out a billion photons from the star for every one we capture from the planet,” said Jason Rhodes, the project scientist for the WFIRST at NASA’s Jet Propulsion Laboratory. “WFIRST should be two or three orders of magnitude more powerful than any other coronagraph ever flown.”

To achieve this level of photonic negation, the WFIRST will be equipped with a coronagraph that holds two flexible mirrors at its core. As light enters the WFIRST, the two mirrors, controlled by thousands of actuators, will flex to compensate for any flaws in the instrument’s optics. The precise, dynamic, deforming dance that the WFIRST will undergo will also be aided by the addition of ground-breaking masks that bend excess starlight around the instrument’s center and into light blocking elements that will help clear the image of unwanted information.

With these combined technologies, NASA expects that it will be able to spot and catalog exoplanets in ways that none of the WFIRST’s predecessors (Hubble, Kepler and the James Webb Space telescopes) could have done before.

“With WFIRST we’ll be able to get images and spectra of [exoplanets], with the goal of proving technologies that will be used in a future mission—to eventually look at small rocky planets that could have liquid water on their surfaces, or even signs of life, like our own,” Rhodes said.