How This Cutting Edge Instrument Will Help NASA Spot Hidden Exoplanets – SlashGear

On board Roman will be a special instrument called a coronagraph which can help in the discovery of exoplanets. This instrument — roughly the size of a baby grand piano — has a special attachment which blocks out light from a star. As counterintuitive as that may sound, it’s actually very important because if you want to see a relatively faint object like a planet, you need to block out most of the light from a much brighter object like the star around which the planet is orbiting.

By putting a mask in front of the telescope, researchers can block out light from bright stars and directly image the planets around them. This opens up the method of direct imaging, which is incredibly difficult to do otherwise. The telescope instruments will also be able to split the light coming from exoplanets into a spectrum, allowing scientists to determine the gases which are present in an exoplanet atmosphere.

The coronagraph instrument includes very important components in the form of two flexible mirrors, which can have their shape distorted by thousands of tiny actuators. This flexibility means that the mirrors can account and compensate for any tiny flaws in the hardware that would otherwise distort the data, making the instrument even more accurate. The mirrors can also allow for diffraction of the light coming from a star, making the readings more sharp.