NASA's Plan To Block Light From Distant Stars To Find 'Earth 2.0'

Daniel_Stuckey (2647775) writes "Over the last five years, NASA's Kepler Space Telescope has found dozens of potentially habitable planets. The only problem is that we can't actually see them, because the glare from those planets' stars makes it impossible to image them directly. A new, audacious plan to completely block out the light from those stars, however, could change all of that. The plan calls for a satellite to be sent out several tens of thousands of miles from Earth. The satellite will unfold a huge, flower-shaped metal shade that will literally block the light of some far-out star to the point where a space telescope, which will directly communicate with Starshade, will be able to image whatever planets are orbiting it directly. It's called Starshade, and, given the name, it works exactly how you might expect it to. If you look directly at the sun, you're not going to be able to see anything in the sky around it. Hold up something between your eyes and the sun to block it, however, and you'll be able to see much better."

Comments

Aperture Science

[RyanFenton]

We do what we must - because we can!

Neat design - always liked the kind of foil origami that goes into satellite construction. Designs like this are great, because they compete well against heavier designs to create a de-facto specialized GIANT EYE IN SPACE. They're also seem a little, ahem, short-sighted in the sense that they may not last long against various sources of degradation, but as proof of concept, this is great science!

It's always cool to see the science get done, for the people who are still alive!

Ryan Fenton

Re:Aperture Science

[Anonymous Coward]

With just a telescope and a target that is easy enough, but then you have a shade orbiting between the two and all three have to be lined up correctly for this to work (reference: try drawing a straight line between three points that are not colinear).

The problem you describe would be difficult if stars and their orbiting planets were sized such that they could fit on a single page of a textbook (or screen on your desktop). (Human-scale analogy: Using 10x digital zoom, try to keep a rapidly-moving object like a jet at an air show using nothing but your cell phone. The jet can fill the frame of the camera if you're lined up, but keeping the camera in line with it is almost impossible because the jet isn't that far away and it's moving very quickly relative to the observer.)

The reality is that the stars are really really really far away, so a starshade at a mere 37000 miles doesn't have to worry about being out of line, and that the planets are really far away from the star. (Human-scale analogy: Using the same 10x digital zoom and a cell phone held close to the eye with one hand, use the thumb of your other hand to block the sun. Easy-peasy even if the sun is huge, because it's so far away that it's basically stationary relative to the camera lens and your occluding thumbshade.)

Wrong focus

[asmkm22]

As interesting as this stuff is, we really need to be focusing on better propulsion methods. Lets figure out how to visit the planets we KNOW exist here in our solar system, and then get excited about planets in others. Lets get an orbital shipyard in place and start hauling in asteroids for materials. Maybe establish a presence on the moon; something like a radio telescope on the far side. Trying so hard to detect these "earth-like" planets in other systems just seems like the scientific equivalent of playing a lottery that has an uncertain payout. I guess the ultimate "prize" would be something like finding an earth 2.0, and directing our communications to it in hopes of maybe discovering some technological-advancing information, ala Contact. Just seems ironic considering all the mathematicians and scientists and such that laugh at the unwashed masses who play the actual lottery, and call it an idiot tax.

Can they make a 3D shade?

[wisebabo]

What I mean is, instead of a shade that looks like a "flower" with "petals" can they make something that looks more like a (very) corrugated sphere?

That way if the spacecraft maneuvers to a new position relative to it, it won't have have to rotate (making it much less complex with no active mechanisms required). Also, multiple telescopes could simultaneously use it from different angles.

It could be a simple inflating balloon (perhaps with a fast setting foam) or something more complex like a "hoberman sphere"(?).

If they put it in geo- sync orbit and made it the appropriate size could multiple ground telescopes use it? With good adaptive optics of course, perhaps firing a laser at it (using it as a reference target) at a different wavelength of course for atmospheric aberration correction.