3 ms·

So many mysteries out there. I can't wait until Webb starts beaming back data and is fully operational. I can only imagine what we'll learn from it.

sandworm101 5y ago
Can webb even point at tabby's? Ive never seen a strait answer on this, but i think webb's sunshield arrangement limits it to objects away from the ecliptic, which is fine if you are looking at stuff outside our galaxy.
- entrep 5y ago
  Webb can 'see' everything but objects between Webb's location and the sun. At each moment, it's limited to part of the sky, but over a whole year, it can observe in all directions.
- pmlamotte 5y ago
  I've been curious about this as well and decided to look it up; there's a nice video that shows it off fairly well[1]. The sunshield is perpendicular to the light coming from the sun, as is the view from the telescope, though the sunshield is large enough that it can be off several degrees and still keep the telescope in shadow. You can rotate the telescope about that axis and remain perpendicular to the sun allowing a 360 degree view forming a plane. As it orbits around the sun that plane is hitting a different slice of the sky so over the course of 6 months you can view everything. [1] https://webbtelescope.org/contents/media/videos/1157-Video https://webbtelescope.org/contents/media/videos/1157-Video
  - sandworm101 5y ago
    That explains the contradictory statements I've seen over the years. The program can view the entire sphere over a period of a year, but at any one moment the telescope only has access to see stars within a particular plane. So it isn't available for ad hoc targeting of interesting things as they happen (nova, transits etc) unless they are in the plane of available options at that moment. That also meshes with the cultural issued behind the scenes. JWST has always been more of an stellar astronomy and cosmology instrument. It won't be much use in looking at closer/moving things like Oumuamua or phenomena like Tabby's star transits that occur at very particular times. So it isn't an instrument for so-called "planetologists", which is the hot field in modern astronomy but was barely a thing when JWST began.
    - Keysh 5y ago
      Of course JWST is an instrument for studying exoplanets (among other things). Something like 24% of the first year’s approved observing proposals are for doing just that. There are coronagraphs in two of the main instruments, all specifically meant for exoplanet observations. https://eos.org/features/overture-to-exoplanets https://eos.org/features/overture-to-exoplanets
      - sandworm101 5y ago
        Exoplanets are one type of planet and their detection is really just a subset of stellar astronomy in that it relies on stellar instrumentation. The hot stuff these days is within the solar system, especially since since the Pluto flyby. Minor plants, planet X, extra-solar objects (Oumuamua) and the hunt for life within our solar system ... these are the big areas of public interest in the next decade and will be the focus for planetology (I still cannot say that without thinking of Herbert).
        Keysh 5y ago
        OK, you're really not making much sense. I mentioned exoplanets because that was a (barely) plausible interpretation of something that was a "hot field in modern astronomy but was barely a thing when JWST began", since the preliminary studies for JWST did happen in the mid-1990s, when exoplanets were first beginning to be found. The actual serious design work, though, was in the early 2000s, when exoplanets were definitely a hot topic. But if what you really mean is "within the solar system" (which, um, excludes "Tabby's star"), well... "barely a thing when JWST began" is complete nonsense. I mean, studying things within the solar system is something astronomy has been doing for literally thousands of years. (And, no, it hasn't suddenly become "the hot field" in any sense, leaving aside the point that there are multiple things that might be considered "hot fields" at the moment, and that there's never a single "hot field" anyway.) JWST is perfectly useful for solar-system science: there are about 22 approved Cycle 1 General Observer proposals in that field, including one specifically meant for any "interstellar object" (like 1I/'Oumuamua or 2I/Borisov) that might show up during the first year: https://www.stsci.edu/jwst/phase2-public/2337.pdf https://www.stsci.edu/jwst/phase2-public/2337.pdf And the second-largest set of Guaranteed Time Observation proposals (proposals from "scientists who helped develop the key hardware and software components or technical and inter-disciplinary knowledge for the observatory"), after "Extra-solar Planets", is "Solar System": https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-gto https://www.stsci.edu/jwst/science-execution/approved-progra...
- bewaretheirs 5y ago
  It's constrained to about 10 degrees in the roll axis, 50 degrees in pitch (-5 to +45), 360 in yaw. At any given moment, it can point anywhere in about 39% of the full sky (inner solar system excluded of course), but can access the entire sky over a period of 6 months. see: https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-observatory-coordinate-system-and-field-of-regard https://jwst-docs.stsci.edu/jwst-observatory-characteristics... Or in video form: https://www.youtube.com/watch?v=y0bOi3kVIBs https://www.youtube.com/watch?v=y0bOi3kVIBs
  - sandworm101 5y ago
    Perspective is funny. When I think of it hanging out there in space I think of it as having 360 in roll. But I guess if you were facing in the direction of the mirror that would be 360 in yaw.
    - bewaretheirs 5y ago
      yeah, really depends on the coordinate system you use but to me it's like a square-rigged ship with the sunshade as the hull, the tower as mast, and the main mirror as sail. And it's consistent with the terminology used to describe parts of the sunshade during deployment -- fore/aft sunshield pallets, port/starboard sunshield booms..
JackFr 5y ago
As someone not involved in the field, I have always gotten the impression that all the major questions are settled, the processes are understood and that the work being done by active astronomers is really only at the margins, fleshing out the details in a word. And I think that's a view often promoted by scientists and the popular press, for the reasons that we have gained a tremendous understanding of the univers over the past 500 years, heck over the past 50 years, and no one wants to focus on talking about what we don't understand. And then you see stuff like this and Oumumamua and its exciting and interesting and then you begin to realize that there's tons of stuff we really have no idea about, that at best we can make plausible explanations and try to rely on Occam's Razor and parsimonous assumptions. I wish there were more of this because I find it delightful and inspiring.
- temp0826 5y ago
  >> I have always gotten the impression that all the major questions are settled This is unfortunate- feels like that mindset could stifle innovation
- sfifs 5y ago
  Well current mainstream cosmologists claim they literally don't know what 80% of the universe is made up of (that's why "dark" matter). So...
  - JackFr 5y ago
    It’s funny — that’s a pet peeve of mine too. To read the popular press you don’t get that impression at all. In fact it’s all authoritative statements about the “best map of far matter yet” or some other conclusion about dark matter. And if (for instance in the comments section of HN) one brings up the fact that they have no idea and dark matter is just a plug between what we know about gravity and what we observe in the EM spectrum, one often gets shouted down.
- robbomacrae 5y ago
  I think there is something to this.. possibly as a side effect for how knowledge is distributed. We are told about the discoveries and the things we found out. We are not told about everything else there is yet to discover, partly because its mostly unknown unknowns.. and it takes a fair bit of digging just to find out what the current big unsolved mysteries are. It's like the more you know the more you realize you don't know. I think it would greatly benefit all of us if we found a way to focus more on what we don't know.

sandworm101 5y ago

Can webb even point at tabby's? Ive never seen a strait answer on this, but i think webb's sunshield arrangement limits it to objects away from the ecliptic, which is fine if you are looking at stuff outside our galaxy.

entrep 5y ago
Webb can 'see' everything but objects between Webb's location and the sun. At each moment, it's limited to part of the sky, but over a whole year, it can observe in all directions.
pmlamotte 5y ago
I've been curious about this as well and decided to look it up; there's a nice video that shows it off fairly well[1]. The sunshield is perpendicular to the light coming from the sun, as is the view from the telescope, though the sunshield is large enough that it can be off several degrees and still keep the telescope in shadow. You can rotate the telescope about that axis and remain perpendicular to the sun allowing a 360 degree view forming a plane. As it orbits around the sun that plane is hitting a different slice of the sky so over the course of 6 months you can view everything. [1] https://webbtelescope.org/contents/media/videos/1157-Video https://webbtelescope.org/contents/media/videos/1157-Video
- sandworm101 5y ago
  That explains the contradictory statements I've seen over the years. The program can view the entire sphere over a period of a year, but at any one moment the telescope only has access to see stars within a particular plane. So it isn't available for ad hoc targeting of interesting things as they happen (nova, transits etc) unless they are in the plane of available options at that moment. That also meshes with the cultural issued behind the scenes. JWST has always been more of an stellar astronomy and cosmology instrument. It won't be much use in looking at closer/moving things like Oumuamua or phenomena like Tabby's star transits that occur at very particular times. So it isn't an instrument for so-called "planetologists", which is the hot field in modern astronomy but was barely a thing when JWST began.
  - Keysh 5y ago
    Of course JWST is an instrument for studying exoplanets (among other things). Something like 24% of the first year’s approved observing proposals are for doing just that. There are coronagraphs in two of the main instruments, all specifically meant for exoplanet observations. https://eos.org/features/overture-to-exoplanets https://eos.org/features/overture-to-exoplanets
    - sandworm101 5y ago
      Exoplanets are one type of planet and their detection is really just a subset of stellar astronomy in that it relies on stellar instrumentation. The hot stuff these days is within the solar system, especially since since the Pluto flyby. Minor plants, planet X, extra-solar objects (Oumuamua) and the hunt for life within our solar system ... these are the big areas of public interest in the next decade and will be the focus for planetology (I still cannot say that without thinking of Herbert).
      - Keysh 5y ago
        OK, you're really not making much sense. I mentioned exoplanets because that was a (barely) plausible interpretation of something that was a "hot field in modern astronomy but was barely a thing when JWST began", since the preliminary studies for JWST did happen in the mid-1990s, when exoplanets were first beginning to be found. The actual serious design work, though, was in the early 2000s, when exoplanets were definitely a hot topic. But if what you really mean is "within the solar system" (which, um, excludes "Tabby's star"), well... "barely a thing when JWST began" is complete nonsense. I mean, studying things within the solar system is something astronomy has been doing for literally thousands of years. (And, no, it hasn't suddenly become "the hot field" in any sense, leaving aside the point that there are multiple things that might be considered "hot fields" at the moment, and that there's never a single "hot field" anyway.) JWST is perfectly useful for solar-system science: there are about 22 approved Cycle 1 General Observer proposals in that field, including one specifically meant for any "interstellar object" (like 1I/'Oumuamua or 2I/Borisov) that might show up during the first year: https://www.stsci.edu/jwst/phase2-public/2337.pdf https://www.stsci.edu/jwst/phase2-public/2337.pdf And the second-largest set of Guaranteed Time Observation proposals (proposals from "scientists who helped develop the key hardware and software components or technical and inter-disciplinary knowledge for the observatory"), after "Extra-solar Planets", is "Solar System": https://www.stsci.edu/jwst/science-execution/approved-programs/cycle-1-gto https://www.stsci.edu/jwst/science-execution/approved-progra...
bewaretheirs 5y ago
It's constrained to about 10 degrees in the roll axis, 50 degrees in pitch (-5 to +45), 360 in yaw. At any given moment, it can point anywhere in about 39% of the full sky (inner solar system excluded of course), but can access the entire sky over a period of 6 months. see: https://jwst-docs.stsci.edu/jwst-observatory-characteristics/jwst-observatory-coordinate-system-and-field-of-regard https://jwst-docs.stsci.edu/jwst-observatory-characteristics... Or in video form: https://www.youtube.com/watch?v=y0bOi3kVIBs https://www.youtube.com/watch?v=y0bOi3kVIBs
- sandworm101 5y ago
  Perspective is funny. When I think of it hanging out there in space I think of it as having 360 in roll. But I guess if you were facing in the direction of the mirror that would be 360 in yaw.
  - bewaretheirs 5y ago
    yeah, really depends on the coordinate system you use but to me it's like a square-rigged ship with the sunshade as the hull, the tower as mast, and the main mirror as sail. And it's consistent with the terminology used to describe parts of the sunshade during deployment -- fore/aft sunshield pallets, port/starboard sunshield booms..

JackFr 5y ago

As someone not involved in the field, I have always gotten the impression that all the major questions are settled, the processes are understood and that the work being done by active astronomers is really only at the margins, fleshing out the details in a word. And I think that's a view often promoted by scientists and the popular press, for the reasons that we have gained a tremendous understanding of the univers over the past 500 years, heck over the past 50 years, and no one wants to focus on talking about what we don't understand. And then you see stuff like this and Oumumamua and its exciting and interesting and then you begin to realize that there's tons of stuff we really have no idea about, that at best we can make plausible explanations and try to rely on Occam's Razor and parsimonous assumptions. I wish there were more of this because I find it delightful and inspiring.

temp0826 5y ago
>> I have always gotten the impression that all the major questions are settled This is unfortunate- feels like that mindset could stifle innovation
sfifs 5y ago
Well current mainstream cosmologists claim they literally don't know what 80% of the universe is made up of (that's why "dark" matter). So...
- JackFr 5y ago
  It’s funny — that’s a pet peeve of mine too. To read the popular press you don’t get that impression at all. In fact it’s all authoritative statements about the “best map of far matter yet” or some other conclusion about dark matter. And if (for instance in the comments section of HN) one brings up the fact that they have no idea and dark matter is just a plug between what we know about gravity and what we observe in the EM spectrum, one often gets shouted down.
robbomacrae 5y ago
I think there is something to this.. possibly as a side effect for how knowledge is distributed. We are told about the discoveries and the things we found out. We are not told about everything else there is yet to discover, partly because its mostly unknown unknowns.. and it takes a fair bit of digging just to find out what the current big unsolved mysteries are. It's like the more you know the more you realize you don't know. I think it would greatly benefit all of us if we found a way to focus more on what we don't know.