Future telescopes to study exoplanets?

[Bubbinski]

In light of today's discovery of Kepler 62f, what follow-up missions are being planned to try to characterize its atmosphere, find out its mass, etc.?  I know that a mission called Terrestrial Planet Finder was planned but later axed.  Are there any alternatives in work for finding out more about these worlds?

In a thread a while back I asked about the possibility of a probe being sent to exoplanets.  Since then I've wrapped my head better around the VAST distances involved.  So I ask this: at this point in time, what kind of telescope project would be the most realistic way of finding out more about known exoplanets?

[randomly]

ATLAST
http://arxiv.org/pdf/0904.0941.pdf
http://en.wikipedia.org/wiki/Advanced_Technology_Large-Aperture_Space_Telescope

[Oli]

EChO (Exoplanet Characterisation Observatory) is one candidate (of 5) for the third m-class mission in ESA's cosmic vision 2015-2025 program.

http://en.wikipedia.org/wiki/EChO
http://en.wikipedia.org/wiki/Cosmic_Vision

Whether it gets selected is another question of course. Launch would be in 2022/2024.

There is also a proposed NASA mission called FINESSE

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

That would launch already in 2017.

[Nomadd]

 I'd wondered if SLS would bring the 8 meter monolithic mirror scope back into play. It would be vastly simpler, less risky and more reliable than the segmented mirrors like JWST.

[grondilu]

TESS, Transiting Exoplanet Survey Satellite, was announced two weeks ago by NASA and should be launched in 2017.  It is one of the five subjects discussed in the latest episode of Scientific American's Spacelab YouTube channel:



Notice that it will only detect exoplanets.  According to the Wikipedia arcticle, further study could then be performed by HARPS or the James Webb Telescope.

Edit:  I realize this does not answer your question, as you were talking about studying already known exoplanets.  Well, I'd say there are plenty of exoplanets out there, so we should not try too hard to study those which are very far away.  We should rather focus on detecting those who are relatively close, so we don't need crazy big hardware to look at them.

[bolun]

So I ask this: at this point in time, what kind of telescope project would be the most realistic way of finding out more about known exoplanets?

CHEOPS

http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=49469

CHEOPS - CHaracterizing ExOPlanet Satellite - will be the first mission dedicated to searching for exoplanetary transits by performing ultrahigh precision photometry on bright stars already known to host planets. It will provide the unique capability of determining accurate radii for a subset of those planets, in the super-Earth to Neptune mass range, for which the mass has already been estimated using ground-based spectroscopic surveys. CHEOPS will also provide precision radii for new planets of Neptune-size and smaller that are discovered by the next generation of ground-based transit surveys.

and

http://cheops.unibe.ch/

http://forum.nasaspaceflight.com/index.php?topic=28309.0

[Oli]

Characterizing the atmosphere of exoplanets would be particularily interesting since it would allow us to detect life.

[simonbp]

Characterizing the atmosphere of exoplanets would be particularily interesting since it would allow us to detect life.

Maybe, but don't hold your breath. It will be be very long time before we are able to take a spectra of a terrestrial planet. And even if we could it's hard to know what to look for. For most of Earth's history, it had a rather boring N2/CO2 atmosphere; O2 is a rather recent occurance.

TESS is the mission to watch, as its product will be Kepler-like transits, but for stars that are much closer and therefore brighter. That will allow much deeper study than is possible for the Kepler planets.

[Jim]

I'd wondered if SLS would bring the 8 meter monolithic mirror scope back into play. It would be vastly simpler, less risky and more reliable than the segmented mirrors like JWST.

[Bubbinski]

Thanks for the replies!

Looking forward to seeing these missions fly and seeing their results (if they are funded of course).  And what capability would JWST offer in this area?

[Oli]

Maybe, but don't hold your breath. It will be be very long time before we are able to take a spectra of a terrestrial planet.

That is why I was pleasantly surprised to see such a mission proposed already for 2017 (FINESSE). 2024 for EChO isn't that far off either.

[BobCarver]

Maybe, but don't hold your breath. It will be be very long time before we are able to take a spectra of a terrestrial planet.

That is why I was pleasantly surprised to see such a mission proposed already for 2017 (FINESSE). 2024 for EChO isn't that far off either.

The best observations of exoplanets will be made from the ground. Several universities are going to build a 30 m telescope on Mauna Kea in Hawai'i which will have multiple spectrographic instruments for observing exoplanets from the infrared to ultraviolet. This is a multiple-mirror telescope in which each mirror will be individually-controlled to eliminate atmospheric distortion by shining a laser beam into the atmosphere for corrective parameters. They will have a telescope with huge collecting and resolving power at a much lower cost than trying to launch a smaller telescope into space.

As I recall this new telescope should be in operation by 2018.

See http://www.tmt.org/

[Oli]

^

Although here it says you need a 80 meter telescope...

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

It has been estimated that a telescope with a diameter of 80 meters would be able to spectroscopically analyse Earth-size planets around the forty nearest sun-like stars. As such, this telescope could help in the exploration of extrasolar planets and extraterrestrial life (because the spectrum from the planets could indicate the presence of molecules indicative of life).

[BobCarver]

^

Although here it says you need a 80 meter telescope...

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

It has been estimated that a telescope with a diameter of 80 meters would be able to spectroscopically analyse Earth-size planets around the forty nearest sun-like stars. As such, this telescope could help in the exploration of extrasolar planets and extraterrestrial life (because the spectrum from the planets could indicate the presence of molecules indicative of life).

I can't see anybody seriously thinking of building an 80 m telescope in space. At least not until we have space colonies there. You sure couldn't launch it in one mission. It would probably take tens of missions, if not hundreds, and the cost would probably be "astronomical."

[Oli]

^

No, that would be an earth-based telescope. But maybe its outdated information, other sources suggest the upcoming very large telescopes (ground-based) will already allow spectroscopy of cooler, habitable planets.

[holgar5]

^

Although here it says you need a 80 meter telescope...

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

It has been estimated that a telescope with a diameter of 80 meters would be able to spectroscopically analyse Earth-size planets around the forty nearest sun-like stars. As such, this telescope could help in the exploration of extrasolar planets and extraterrestrial life (because the spectrum from the planets could indicate the presence of molecules indicative of life).

But first you would need to detect the Earth-sized exoplanets orbiting the nearest Sun-like stars. TESS may detect the transiting ones, but the geometric probability for transits is not very high for planets in the habitable zone of Sun-like stars, thus you would not detect most of them with TESS. An astrometrical search with a precision of sub μas could find all these planets for the nearest Sun-like stars. SIM lite is/was such a project. In Europe there is a proposal for a mission called NEAT (Nearby Earth Astrometric Telescope) with 0.05 μas precision. It would search the 200 nearest Sun-like stars for Earth-sized planets. For more information please see http://neat.obs.ujf-grenoble.fr/NEAT.html .

[Blackstar]

I'd wondered if SLS would bring the 8 meter monolithic mirror scope back into play. It would be vastly simpler, less risky and more reliable than the segmented mirrors like JWST.

Look up the report "Launching Science" from the National Academies Press. We addressed the big monolithic mirrors there.

The simple answer is that big instruments cost big piles of money. You could do some outstanding science with a large aperture telescope like that, but it would cost a lot of money. Will we have the money to pay for it?

And allow me to bore you for a second (how's that for salesmanship):

It helps to understand how new large space science projects get approved and funded in the U.S. Look up the astronomy decadal survey. The very quick answer is that unless a major project gets prioritized in the decadal survey, it will not get built. There's a difference between science discoveries that are currently hot and exciting and very public and what the community of scientists are actually interested.

[Oli]

But first you would need to detect the Earth-sized exoplanets orbiting the nearest Sun-like stars.

Well I doubt there will be so many nearby systems such that you cannot target one after the other. The GPI (Gemini) and SPHERE (VLT) instruments will be able to image Jupiter-sized exoplanets, starting at the end of this year. The very large telescopes currently planned (TMT, E-ELT) could be capable of doing the same for small rocky planets (although they downsized the E-ELT mirror from 42m to 39m, making that goal significantly harder to achieve).

[simonbp]

It honestly doesn't matter; even if we had perfect spectra of a terrestrial planet, we'd still struggle to figure what was (and wasn't) a signature of life.

Exoplanet atmospheres is a bit of a fad at the moment, as it's just about technologically possible, so all the observers are all trying to put themselves in politically favourable positions. In reality, it's highly unlikely that we will detect a biosignature in at least the next 20 (if not 100) years. Which is why most of us in the exoplanet theory community are focused on solar system architectures (rather than habitability); Kepler has provided enough data to properly study architectures, but not much else.

And if we do detect something, noone will believe a signature from a terrestrial telescope; the preceise things we would be looking for are also the bands that the telescope has to look through in Earth's atmosphere. So, it will have to be a space telescope that does the detection.

[go4mars]

Space-based optical interferometry. 
As far as I know, only 'Planetary Resources' is actively working toward that goal (and assuming a continuation of Moore's law).