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Does anyone here have an idea of which kind of resolution https://en.wikipedia.org/wiki/James_Webb_Space_Telescope https://en.wikipedia.org/wiki/James_Webb_Spac

Does anyone here have an idea of which kind of resolution https://en.wikipedia.org/wiki/James_Webb_Space_Telescope https://en.wikipedia.org/wiki/James_Webb_Space_Telescope will provide? I'm assuming that this little rock might not even occupy a single pixel, but I'd love to be wrong.

Diederich 10y ago
Answering my own question via the reddit AMA: https://www.reddit.com/r/askscience/comments/4zdkra/askscience_ama_series_we_have_discovered_an/d6uzf24 https://www.reddit.com/r/askscience/comments/4zdkra/askscien... Says we'd need about 30 milliarcseconds, while, as noted elsewhere, Webb provides 100. Damn!
smeyer 10y ago
The JWST has an angular resolution of 0.1 arc seconds (according to a quick google search). This means a pixel at a distance of a parsec will correspond to about 0.1 astronomical units, which is about 20 times the radius of the Sun. Of course, this doesn't mean that the telescope can't image light from a smaller planet, just that there would be no resolution to distinguish features on the planet itself. Similarly, even though lots of stars and other astronomical objects are too small to resolve, we can still see the light from them with telescopes (and our eyes).
- ingenter 10y ago
  I'd like to add a few things: - 1 parsec ~~ 3.26 light years. - pixel coverage ~ angular resolution * distance. pixel coverage ~ 0.1 * AU / (distance / 3.26 light-years)
stickydink 10y ago
Q: Approx. how good will the resolution be when direct imaging exoplanets? (asked by @JakePeriphery) A: Resolution? JWST's cameras can image gas giant planets greater than a few AU from their stars. http://jwst.nasa.gov/faq_tweetchat3.html http://jwst.nasa.gov/faq_tweetchat3.html
- smeyer 10y ago
  That means that the distance from the planet to the star will be within the resolution, doesn't it? It sounded more like Diederich was asking about the scale of the planet itself being within the resolution.

Diederich 10y ago

Answering my own question via the reddit AMA: https://www.reddit.com/r/askscience/comments/4zdkra/askscience_ama_series_we_have_discovered_an/d6uzf24 https://www.reddit.com/r/askscience/comments/4zdkra/askscien... Says we'd need about 30 milliarcseconds, while, as noted elsewhere, Webb provides 100. Damn!

smeyer 10y ago

The JWST has an angular resolution of 0.1 arc seconds (according to a quick google search). This means a pixel at a distance of a parsec will correspond to about 0.1 astronomical units, which is about 20 times the radius of the Sun. Of course, this doesn't mean that the telescope can't image light from a smaller planet, just that there would be no resolution to distinguish features on the planet itself. Similarly, even though lots of stars and other astronomical objects are too small to resolve, we can still see the light from them with telescopes (and our eyes).

ingenter 10y ago
I'd like to add a few things: - 1 parsec ~~ 3.26 light years. - pixel coverage ~ angular resolution * distance. pixel coverage ~ 0.1 * AU / (distance / 3.26 light-years)

stickydink 10y ago

Q: Approx. how good will the resolution be when direct imaging exoplanets? (asked by @JakePeriphery) A: Resolution? JWST's cameras can image gas giant planets greater than a few AU from their stars. http://jwst.nasa.gov/faq_tweetchat3.html http://jwst.nasa.gov/faq_tweetchat3.html

smeyer 10y ago
That means that the distance from the planet to the star will be within the resolution, doesn't it? It sounded more like Diederich was asking about the scale of the planet itself being within the resolution.