High-Res Pictures of Exoplanets

[zx82]

Is it possible (or will it be possible) to take high resolution pictures of exoplanets? All we can see now is little tiny dots at best, but will any telescopes planned for the future be able to deliver images where we can actually get a sense of what the planet looks like? How big would such a telescope have to be? What are the obstacles preventing this and will they be surpassed in our lifetime?

Sorry I don't know a lot about astronomy but I recently became interested in this question upon hearing about the Kepler mission. Expertise would be appreciated !

 

[nimbus]

I'll let the specialists answer in detail.. But just as an idea of the ballpark... The Hubble telescope can barely image Pluto. This is what its resolution looks like:
http://hubblesite.org/newscenter/archiv ... 9/image/a/

The closest thing to an actual visualization of exoplanets that I know of is the planned New Worlds Observer mission, which'll use a shade aligned with a large telescope to allow said telescope to not be blinded by the stars' light.

 

[zx82]

I'll let the specialists answer in detail.. But just as an idea of the ballpark... The Hubble telescope can barely image Pluto. This is what its resolution looks like:
http://hubblesite.org/newscenter/archiv ... 9/image/a/

Yeah that's more along the lines of what I was thinking...I don't mean high-res like Google Earth pictures but more like the picture you showed or Hubble's pictures of Jupiter...something along those lines.....Just want to know if I'll be alive when I see the day (in my twenties now) and what the technology hurdles are...

Thanks.

 

[MeteorWayne]

Unfortunately, until we send a probe to another stellar system with planets, they will forever be points of light. We will be able to learn something about their atmospheres by looking at the spectrum of reflected and transmitted light from the star, but we will not see any kind of views of the surfaces.

 

[andy_krishna]

There was a program called "400 YEARS OF THE TELESCOPE: A JOURNEY OF SCIENCE, TECHNOLOGY, AND THOUGHT" shown in PBS HD channel last week.

This program discussed a lot about Telescopes and how it evolved and how it was used in centuries ago....

This program also had details about hubble and future mission to new install a huge telescope lens etc.... When installed, that will be the largest telescope ever.....

I don't remember the exact details now...

 

[nimbus]

Wayne, could you definitely rule out focalisation by metamaterials as unfeasible telescope component for this? To directly and distinctively image exoplanets?

 

[MeteorWayne]

Not sure exactly what you mean by "focalisation by metamaterials" but pure basic physics of light limits the resolution of a telescope based on the wavelength being investigated, and the diameter of the reflector. When we have telescopes the size of the solar system, then we can see distant planetary surfaces. Until then, not so much....

 

[nimbus]

I'm sorry I don't understand how wavelength is a problem that implies scopes the size of the solar system to image exoplanets in the visible spectrum. Metamaterials have recently been used to bend light (around said metamaterials, making them "invisible"), and my thought was that this same light bending could be used to focus light from those tiny pinpricks into larger areas... is it at this point that wavelength is an inherent deal-breaker?

 

[DrRocket]

Unfortunately, until we send a probe to another stellar system with planets, they will forever be points of light. We will be able to learn something about their atmospheres by looking at the spectrum of reflected and transmitted light from the star, but we will not see any kind of views of the surfaces.

That state of ignorance is an outrage. Something needs to be done, and done right away. Congress should investigate.

I think we should a congressional delegation (all 535 of them if my vote counts) to immediately investigate Gliese 581d or Gliese 581e -- I really don't care if they go the inhabitable one or not. If they decide to investigate the surface of the star first-hand, that is also just dandy. There is no time to delay. Launch shold be immediate. Maybe Pelosi can donate use of her new plane -- we'll just put a little rocket boost on the tail.

 

[DrRocket]

I'm sorry I don't understand how wavelength is a problem that implies scopes the size of the solar system to image exoplanets in the visible spectrum. Metamaterials have recently been used to bend light (around said metamaterials, making them "invisible"), and my thought was that this same light bending could be used to focus light from those tiny pinpricks into larger areas... is it at this point that wavelength is an inherent deal-breaker?

The limits of resolution are determined by wavelength and lens diameter. At interstellar distances the angle subtended by a feature on a planet is rather small. Note that the entire star looks like a point.


http://en.wikipedia.org/wiki/Optical_resolution

 

[thnkrx]

There was a somewhat 'far out' proposal a decade or two back, if memory serves that might allow for decent resolution of extra solar planets. The scheme involved using the sun as a lens of sorts , with the foci point being at different locations in the solar system. (Sorry, yes, this is a lousy explanation, but this is from memory, and from a long time ago to boot.) If I remember correctly, one of the people proposing this said it should be possible to obtain resolution on the continents of extra-solar planets.

 

[MeteorWayne]

Well, since you can only see past the sun during fleeting total eclipses, that doesn't seem like a very viable idea.

 

[zx82]

For those who might be interested in this topic, it looks like this might be possible within our lifetime. There is a French astronomer by the name of Antoine Émile Henry Labeyrie from College de France who has a proposal to build an extremely large interferometer in space, consisting of around 150 3 metre lens pieces spread over 100km which would be able to make out surface details of planets 10 light years away...this would include details such as continents, seasons, etc. This has gotten me excited and I hope I am around to see this dream become a reality. The major drawback of this of course is cost, but hey at least now I know it is possible. For more information please see these links.

http://www.wisegeek.com/what-is-a-hypertelescope.htm

http://en.wikipedia.org/wiki/Antoine_%C ... y_Labeyrie