How the Webb Telescope Will Explore Interstellar Objects (space.com) 18
Astronomers have only caught glimpses of the two interstellar objects identified in our solar system, reports Space.com — but there's hope that the Webb Space Telescope will show us more:
"With Webb, we can do really interesting science at much fainter magnitudes or brightnesses," Cristina Thomas, an astronomer at Northern Arizona University, said in a statement from the Space Telescope Science Institute in Baltimore, which oversees operations for the Webb mission. Thomas is on a research team that has arranged to use the observatory to study an interstellar object, should one appear during the telescope's first year of work.
Webb brings some new talents to the table as well. "The supreme sensitivity and power of Webb now present us with an unprecedented opportunity to investigate the chemical composition of these interstellar objects and find out so much more about their nature: where they come from, how they were made, and what they can tell us about the conditions present in their home systems," Martin Cordiner, principal investigator of the project, said in the statement. Cordiner is an astrophysicist at NASA's Goddard Space Flight Center in Maryland and at The Catholic University of America in Washington, D.C....
"We've never been able to observe interstellar objects in this region of the infrared," Thomas said. "It opens a lot of opportunities for the different compositional signatures that we're interested in. That's going to be a huge boon for us!" Specifically, the team would use infrared observations to study any gas and dust that the interstellar object is emitting, giving scientists a taste of the object's native system.
Right now, far out in space, the Webb Telescope has finished the first stage of aligning its 18-segmented primary mirror, reports another article at Space.com. "A single star that the observatory looked at was deliberately rendered 18 times into a hexagonal shape.
"Eventually, those 18 images will perfectly align into a single, sharp focus, but the interim result portrays a star repeated perfectly in a hexagonal pattern reminiscent of a stunning celestial snowflake."
Further Reading: "Exclusive interview: answers to 20 questions from the James Webb Space Telescope team."
Webb brings some new talents to the table as well. "The supreme sensitivity and power of Webb now present us with an unprecedented opportunity to investigate the chemical composition of these interstellar objects and find out so much more about their nature: where they come from, how they were made, and what they can tell us about the conditions present in their home systems," Martin Cordiner, principal investigator of the project, said in the statement. Cordiner is an astrophysicist at NASA's Goddard Space Flight Center in Maryland and at The Catholic University of America in Washington, D.C....
"We've never been able to observe interstellar objects in this region of the infrared," Thomas said. "It opens a lot of opportunities for the different compositional signatures that we're interested in. That's going to be a huge boon for us!" Specifically, the team would use infrared observations to study any gas and dust that the interstellar object is emitting, giving scientists a taste of the object's native system.
Right now, far out in space, the Webb Telescope has finished the first stage of aligning its 18-segmented primary mirror, reports another article at Space.com. "A single star that the observatory looked at was deliberately rendered 18 times into a hexagonal shape.
"Eventually, those 18 images will perfectly align into a single, sharp focus, but the interim result portrays a star repeated perfectly in a hexagonal pattern reminiscent of a stunning celestial snowflake."
Further Reading: "Exclusive interview: answers to 20 questions from the James Webb Space Telescope team."
TL;DR version (Score:3, Funny)
The application of science, engineering, and definitely not a gigantic pentagram to channel demonic power because NASA would totally never do that. I'm not sweating, you're sweating so stop asking about the pentagram that definitely isn't in the blueprints, so don't look!
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Beeees in Spaaaace!
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So it's not really MTG's Jewish Space Laser?
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So it's not really MTG's Jewish Space Laser?
Even if it were a space laser, it's pointed in the wrong direction (away from Earth) to start wildfires in California ...
(TL;DR: There's probably no science MTG, and that sect, can't/won't get wrong.)
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I can neither confirm nor deny that allegation.
How the Webb tescope explores things (Score:2)
by looking at them in the infrared
I'm glad to hear setup is going well (Score:1)
...I was really afraid something would go wrong; that's a complicated gizmo to unfold.
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Might have been a better FP, but overall a disappointing discussion so far.
In the Funny category, I was looking for some "are looking for" jokes. Most obviously, "This is the space telescope you are looking for", but with a more astronomic twist, such as "These are not the quasars you are looking for."
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The only "make or break" point was the unfolding of the secondary antenna. Any one (or maybe more) of the segments could fail and the images would be usable after image manipulation (i.e. digitally "delete" the part of the image generated by the not aligned mirror segment).
Even so, there is a bit of "redundancy" in the segments' alignment mechanism so I think they can get perfect results even with one non working control mechanism per segment.
The pointing problem (Score:3)
It seems to me (only from what I have read, no expert), that the Webb has a pretty limited set of viewpoints available to it at any given time. Obviously anything sunward is off limits. So that's at least 180 degrees of blind spot, and that portion of the universe will only become available over the course of months as the Earth orbits the Sun. Also I am not sure that it can point directly away from the sun, I have not seen an elevating mechanism shown in any of the depictions. It may be that the entire platform has to point the telescope.
The Webb reportedly uses "six reaction wheels to rotate the observatory".
https://www.jwst.nasa.gov/cont... [nasa.gov]
My suspicion is that it can only be rotated around in a plane, with a limited amount of traversal above the plane. So if you want to get a good close look at some potential interstellar object zipping through the solar system it is going to have to be appearing within a fairly narrow window of visibility for the Webb. And also if you want to reserve observation time for anything whatsoever, the central region of the Milky Way for example, it will only be available during some limited window of time.
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Very roughly, you can imagine it's on a fully rotatable turret on a pole from Sun to Earth and L2 (with base oriented towards Sun and Earth) and with some -5 degrees "depression" and +40 degrees "elevation". It can't look "straight up" (away from the Sun), so it will need to wait until the "target" gets "low enough" (the 100 degrees of "straight up" will pass in 100 days).
If your target is perpendicular to the Earth-Sun rotation plane, you could follow it year long.
If the target is "straight above", after a
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Thanks for that info (assuming you know what you are talking about). Is the telescope actually mounted on some kind of platform that rotates independently from the entire space vehicle? And it can tip up as much as 40 degrees? If so that's a lot more freedom of movement than I had expected.
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That would be mechanically unsound - space has a tendency to jam any moving mechanism, you can't use greases in space, the "cold" side where the telescope is situated sits at some -250 Celsius degrees. Having moving mechanisms exposed to space, with no maintenance possible, is a recipe for failure.
As it is, the heat shield has a larger and a smaller diagonal so it can sweep a larger angle on one direction than on the other.
There are some movies about JWST (worth watching), that is how I think it's working -
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So in actuality they do reposition the entire spacecraft in order to point the telescope as I originally suspected. Obviously the telescope always has to be shaded. Here's a JWST webpage I found that gives info about the "field of regard".
https://jwst-docs.stsci.edu/jw... [stsci.edu]
"The FOR is defined by the allowed range of boresight pointing angles for the observatory relative to the sun line, which must remain in the range 85 to 135 at all times to keep the telescope behind the sun shield."
"As a result of the FOR,
No comments? ;) (Score:2)
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