PlanetQuest is NASA's effort to search for new Earths, exoplanets like ours that would probably contain life too. They're doing some really cool stuff, like this sunflower-telescope combo spaceship—"a cutting-edge effort to take pictures of planets orbiting stars far from the sun." Imagine that—seeing the actual planets!
It's a simple concept: in order to be able to see planets far away from us we need to block the light of the stars that illuminates them, which is billion times more intense than the light the planets reflect. That's what the flower starshade does:
Working in conjunction with a space-based telescope, the starshade is able to position itself precisely between the telescope and the star that's being observed, and can block the starlight before it even reaches the telescope's mirrors.
With the starlight suppressed, light coming from exoplanets orbiting the star would be visible. Using this technology, astronomers would be able to take actual pictures of exoplanets—images that could provide clues as to whether such worlds could support life as we know it.
There's a reason why the starshade looks like flower too, according to JPL's lead starshade engineer Dr. Stuart Shaklan:
The shape of the petals, when seen from far away, creates a softer edge that causes less bending of light waves. Less light bending means that the starshade shadow is very dark, so the telescope can take images of the planets without being overwhelmed by starlight.
But while the idea is simple and clever, the actual thing is not. It's quite a complicated endeavour, although they are progressing steadily. First, the starshade has to deploy from a tiny package into this complex and huge surface with a complex geometry. And then, even more complicated, it has to move around independently from the telescope, according to Shaklan:
We can use a pre-existing space telescope to take the pictures. The starshade has thrusters that will allow it to move around in order to block the light from different stars.
Now I'm excited. I can't wait to have this in space and start seeing the first pictures of real planets beyond our solar system.