Comments on: That’s My Favourite Kind Of Planet.

By: The Quickfire Round. « The Scientific Gamer

The Quickfire Round. « The Scientific Gamer — Tue, 24 Jul 2012 11:01:25 +0000

[...] if you’ll recall my post on exoplanets, the vast majority of exoplanets aren’t found by direct observation but rather through techniques [...]

By: nobody

nobody — Thu, 28 Jun 2012 05:44:45 +0000

“extrasolar planet orbiting another star”
>extrasolar planet
>orbiting another star

Not sure if that’s a tautology or if your reading audience spans more than I thought but either way I like it.

By: Barry’s Guide To Barycentres. « The Scientific Gamer

Barry’s Guide To Barycentres. « The Scientific Gamer — Mon, 14 May 2012 11:00:38 +0000

[...] it is a slight “wobble” on the part of the Sun. Nevertheless this motion can be detected, and as previously mentioned it’s one of the methods we use to detect exoplanets orbiting other stars. Hopefully by this point [...]

By: Smurf

Smurf — Fri, 20 Jan 2012 10:30:48 +0000

I’m learning!

By: hentzau

hentzau — Thu, 19 Jan 2012 12:17:51 +0000

P.S. – Large telescope arrays like the VLT can analyse exoplanets in other ways, like spectroscopy; http://www.eso.org/public/news/eso1002/ is a news story about it getting the first direct light spectrum emitted from an exoplanet, which will tell us about its composition via chemical absorption lines.

By: hentzau

hentzau — Thu, 19 Jan 2012 12:14:15 +0000

“So does this mean that nobody has actually laid eyes on a planet outside our own solar system and we don’t really know what they look like other than gas-giant, earth-like, etc?”

You see that coronagraph of the three planets b, c and d? That’s just about the best direct image we’ve got.

“Could we ever do that from Earth or is it impossible even with future technologies?”

No, because even if a planet existed which could be imaged telescope technology is ultimately limited by certain hard physical laws governing their resolution – see http://en.wikipedia.org/wiki/Angular_resolution – that mean building a telescope ( or even a telescope network – see http://en.wikipedia.org/wiki/Astronomical_interferometer ) with the required focal length to resolve an extrasolar planet is practically impossible. For example, this – http://en.wikipedia.org/wiki/File:Nebula_around_Betelgeuse.jpg – is the sort of resolution we get out of the Very Large Telescope array. The black disc is Betelgeuse, which is a star roughly twenty times the size of the Sun. Any planet would still show up as a pinprick on this image.

“Will we ever see a picture of an exoplanet without sending a probe?”

Probably not. You have to bear in mind that there’s lots of stuff *in our own solar system* we haven’t been able to directly image in any meaningful way yet; we won’t have a decent picture of Pluto until the New Horizons probe gets there in 2014.

By: Smurf

Smurf — Thu, 19 Jan 2012 11:50:28 +0000

Huh, 1992? I always figured other planets had been discovered as early as the ones in our solar system and we were up to thousands of discoveries. I think I’ve just assumed that finding planets was just like finding stars but you used better telescopes. i.e. you could actually see the exoplanets. So does this mean that nobody has actually laid eyes on a planet outside our own solar system and we don’t really know what they look like other than gas-giant, earth-like, etc?

Could we ever do that from Earth or is it impossible even with future technologies? Will we ever see a picture of an exoplanet without sending a probe?