Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 


Forgot your password?
Close
typodupeerror
×
Space

NASA's Plan To Block Light From Distant Stars To Find 'Earth 2.0' 92

Posted by Unknown Lamer from the starshader-glides-in-front-of-a-star dept.
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."

This discussion has been archived. No new comments can be posted.

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

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

Comments Filter:

  • Mr. Burns thought of it first. (Score:3, Funny)

    by Anonymous Coward on Monday May 19, 2014 @10:10PM (#47043177)
    Yet one more aspect of our lives that the government wants to control!

  • Aperture Science (Score:4, Interesting)

    by RyanFenton ( 230700 ) on Monday May 19, 2014 @10:13PM (#47043191)

    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

    • Yeah but how effective will this be? A few tens of thousands of miles is barely 10% of the way to the moon [google.com].

      Objects whiz by at tens of thousands of miles per hour (orbital velocity) [wikipedia.org]. By the time you focus the telescope, will it and shade already be out of sync? I am no physicist, but I understand that when things move very fast it is difficult to keep them in sync (reference: I have been to the circus and watched the motorcycles in the spherical cage). With just a telescope and a target that is easy enough,

      • Re: (Score:1, Interesting)

        by 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 l

        • so a starshade at a mere 37000 miles doesn't have to worry about being out of line

          Actually, it is 37,000 kilometres, so that it is even better for the shade. But I am not sure about the size of the starshade because it looks quite small (on TFA)...

      • Objects whiz by at tens of thousands of miles per hour. By the time you focus the telescope, will it and shade already be out of sync?

        The shade only has to cover the star, not aim directly at the plant. So this is more like blocking out the sun to see a baseball than tracking a baseball with a camera.

      • You are correct that there is not an orbital alignment that would passively keep the telescope and shade in alignment with a star. They plan to put the system in a solar orbit (so that the speed at which alignment shifts will be slower than if it were in Earth orbit) and also they will have to actively guide the telescope using ion thrusters in order to maintain the correct alignment during an observation. Because of this, observation windows will be relatively short. This requirement for active guidance

    • Not only great science. Great and sound engineering, also. The document behind the second link [nasa.gov] has visibly been written by good engineers, who understand their trade. Remember the old tongue-in-cheekish adagium: "without engineering, science would be only philosophy"....

      • Great and sound engineering, also.

        Nonsense! They just need to run their telescopes during the day when the stars aren't visible!

  • If you look directly at the sun, you're not going to be able to see anything in the sky around it

    If you look directly at the sun, you're not going to be able to see much of anything for quite a while

    • "When I was a little kid, my mother told me not to stare into the sun. So once when I was six, I did. The doctors didn't know if my eyes would ever heal. I was terrified, alone in that darkness. Slowly, daylight crept in through the bandages, and I could see, but something else had changed inside of me"

      -Maximillian Cohen

  • It's a good solution, but how good of a resolution will we get out of it? Will we only see something along the lines of the "pale blue dot" image that Voyager took of the Earth?
    Is there anything really to be gained or learned about imaging a distant planet in this way? Could we can get finer information about its composition?

    • Re: (Score:2)

      by dierdorf ( 37660 )

      Even the pale blue dot would be plenty big enough to show that the planet in question (a) has water, and (b) has an oxygen atmosphere. Those two features, as far as we know, guarantee life is present.
      Take a long exposure of the night side of our blue dot and we could almost certainly detect the lights of civilization.

    • Re: (Score:1)

      by Anonymous Coward
      In principle you will be limited to the planet being a single dot for the near term. If you had an Earth sized planet a mere 10 light years away, you would need a focusing lens or mirror ~10 kilometers in size (or some array of mirrors spread out that far doing interferometry, which is difficult in the visible bands) just to start resolving it as more than one pixel. Although there are a lot of tricks that you can do even if all you get is one pixel, as you can use that the illumination changes as the pla

    • Re: (Score:2)

      by snooo53 ( 663796 )
      Sure, there's a lot of science one can do even with a handful of pixels. The spectra tells us the atmospheric composition and the way the pixels change over time can tell us the size, orbit, rotations, perhaps even weather patterns or if the planet has any moons and the composition and size of those.

  • The satellite will block the liught coming from the star impinging on the Earth thus reduce the heating of the Earth by 0.00001 %.

    • 0.00001% is a teensy weensy bit off.

      The brightest star in the sky is Sirius. It's 8.6 light years away (or 545,000x the distance of the Sun), and 25x the luminosity of the Sun.

      Through the wonders of the inverse square, if the amount of radiation we get from the Sun is 1, then the relative amount of radiation we get from Sirius is 25/(545,000^2). So, Sirius (the brightest star in the sky) generates about 0.00000001% of the heating of the sun.

  • Wrong focus (Score:2, Interesting)

    by asmkm22 ( 1902712 )
    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
    • Yup. It is a lottery. Just like when the telescope and microscope were invented.

    • In terms of interstellar planetary observations we're not even at the peering through hand-ground lenses in a medieval observatory stage yet, we're still trying to squint-count the pleiades on a windblown steppe as a test of eyesight. These are part of many tiny progressive advances that will ultimately lead to things like a constellation of observation satellites in a globe around the sun using its gravitational field to magnify distant worlds to an incredible extent. Taken individually it mightn't look li

    • Better propulsion methods? Considering we've been devising all sorts of propulsion methods for the last 50 years, what exactly should we expect from "propulsion"?

      Frankly, I think "propulsion" is a dead end, we need to start figuring out physics to the point where we can either teleport physical items long distances, create wormholes or warp space. Propulsion will not get us out of this solar system and propulsion will not make travel within the solar system economically viable. We need to be able to get to

      • For those things to happen we need to lower launch costs dramatically and come up with better closed loop systems or ways to use resources already in space or other worlds, i.e. making colonies more or less elf-sufficient, at least for basic necessities (air, food & water, fuel & power). We'll still need this even if we can reduce the trip to mere days, and once we have this, a trip time of several months would be inconvenient but not a blocker.

    • We have better propulsion. Most of it requires a nuclear reactor being launched into orbit so it can be attached to the ship to power said engines. Good luck with that.

      Looking at other planetary systems teaches us something about our own. If we find "earth-like" planets, that helps us understand what is required to create an Earth, how stable an Earth is, where we should look for them, and what an Earth (besides our sample of 1) looks like. It's invaluable information even if we can't get there.

    • Realistically anything short of warp-gate research is going to leave us doomed. Mars and the Moon don't give us much.

    • Re: (Score:2)

      by idji ( 984038 )
      NASA is focusing on research and new tech as it should and Starshade is an excellent example.
      NASA shouldn't do an orbital shipyard and asteroid hauling - that is engineering - let SpaceX and Google do that in private enterprise.

    • Re: (Score:2)

      by Kjella ( 173770 )

      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.

      That's because so many people (you included, apparently) don't realize it's a negative-sum game. People buy lottery tickets, the lottery takes a piece of the pool for operating costs, profit and/or charity and return the remaining as prizes and unlike for example poker there's nothing you can do to improve your odds. Particularly if you play for small sums of money (say less than a month's salary) it is extremely unlikely you'll be cash positive even if you occasionally win. I guess there's the dream of win

  • an artificial stellar eclipse

  • Can they make a 3D shade? (Score:4, Interesting)

    by wisebabo ( 638845 ) on Tuesday May 20, 2014 @12:16AM (#47043725) Journal

    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.

  • Dammit, Earth 1.0 is obsolete already. Now I know I am getting old.

  • Two spacecraft orbit the Sun in the same path as the Earth, one leading and one following. Each uses a disc to block direct light but capture incredible images of solar events and weather. Stereo A and B. Audacious? No. Science? Si, mon. From NASA: http://www.nasa.gov/mission_pa... [nasa.gov]
  • I remember from my long ago courses of optics that you can't simply block the light from a pinpoint source: it creates diffusion [wikipedia.org] around the blocking object. How do they work around this ?

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

    Won't the aliens get cold? Seems a bit harsh.

    Alternative post: it got cancelled years ago, and they need to get over it.

  • You will damage your eyesight...don't do, it opticians make enough as it is.

  • If we have the technology to build this kind of giant umbrella, can't we put one somewhere between earth and the sun to provide shadow over the poles and prevent global warming ?

  • Why not make the shade a sphere (or at least sphere-ish)? Then you could have multiple telescopes use it to image different stars simultaneously, then have the telescopes reposition. This way you could also scale it up in the future by adding more telescopes if it proves to be a fruitful enough project.
  • Why not just using black marker on telescope lense?

  • The technical term for this type of telescope is "occulting".

    Naturally, this term would freak people out, so they circumlocute to avoid using it.

Slashdot Top Deals

Love may laugh at locksmiths, but he has a profound respect for money bags. -- Sidney Paternoster, "The Folly of the Wise"

Close