19

Hmmm no, it wouldn't be cluttered with debris, and yes, it's a good idea to park the JWST (James Webb Space Telescope) at the Sun-Earth L2 point. The five Lagrange points are unstable, for one because of the gravitational anomalies of the two massive bodies of the Lagrange system, eccentric orbits, and there are many other factors to their instability. At ...


17

Hubble was in low earth orbit, and was always intended to be serviceable. In fact, the original plan for Hubble was to have the space shuttle carry it down from orbit and take it back up, but they decided that was too risky compared to servicing in orbit. JWST, on the other hand, will be at the Earth/Sun L2 Lagrange point, like WMAP and Planck before it. ...


7

From what I understand, James Webb, if used in conjunction with a successful starshade (being developed at MIT), should be able to detect close in planets orbiting nearby stars. However, getting good atmospheric spectra of these planets directly (from planet's blackbody IR emission) is unlikely. What we must hope for is that TESS, which should be going up in ...


4

The role of the microshutters is NOT to act as pinholes or coded aperture and to produce a focused image, similar to a mirror or lens. Its job is just to separate the the light from different sources. This is achieved simply by opening only the shutters corresponding to the sources of interest. See the following image: This is important for spectroscopy as ...


4

Are you asking about the PSF (point-spread function)? There are some simulations & basic images available as well as a downloadable package you can use to compute the PSF for a particular instrument and wavelength. Since the telescope hasn't been fully assembled yet these are based on simulations. https://www.stsci.edu/jwst/science-planning/proposal-...


4

Objects are not place at the Sun-Earth L1 or L2 Lagrange points. They are instead placed in pseudo orbits about these points. These pseudo orbits intentionally avoid being directly in line with the Earth and the Sun for two key reasons. One reason is that these points are directly in the line between the Sun and the Earth. An object at the Sun-Earth L1 would ...


4

At 1.5 million km JWST will be roughly 4,000 times farther than the ISS when it's overhead, and very roughly a tenth of the cross-section. So if the ISS can be as bright as -4 magnitude, then JWST will be very roughly +16. That's well within the range of small observatories and large amateur telescopes. But there is going to be quite a lot of variability in ...


3

The JWST images will have various artifacts. I found a web page that summarises the situation for the Near Infrared Imager and Slitless Spectrograph (NIRISS). The image below (taken from that webpage) shows simulated point sources as they would appear on the detector (including the sampling by the 0.0656 arcsec pixels). The greyscale is on a logarithmic ...


3

The list of JWST approved programs for Cycle 1 (12 months long, starting after the 6 month long commissioning phase following launch) is available here. If you unfold the Exoplanets and Disks science category, you will see the programs, along with the links to proposal abstracts and target lists. Looking at the proposal titles only, the exoplanet targets for ...


3

The orbit is around L2 at a vast distance from it, perhas > 10,000 km around it. This is a map of the stability of the lagrangian points: L2 is unstable, like balancing a pencil on it's tip, but l4 and l5 have a force restoring a deprating object back onto L4. There is a lot les space debris at L2 that orbiting the earth, JWST has less chance of a hit ...


2

According to this article, the TRAPPIST-1 system is supposed to be studied by JWST with the potential to detect atmospheres' composition in infrared band. So at last 40 ly (approx. 12 pc) should work. Somewhere else I read there is an assumption to study earth-like exoplanetary atmospheres at distance of 10-20 pc. But it might be better to see it from ...


1

I found this link that might seem interesting : https://www.nasa.gov/feature/jpl/nasa-mission-will-study-the-cosmos-with-a-stratospheric-balloon The article in the link doesn't clearly specify the actual instruments or their functionality, but as this is an official article, I thought it might be useful. The only info that NASA has officially released about ...


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