The instrument calibration period was planned for 2 months after reaching desired temperature.
Instrument calibration involves operating the instruments, receiving the data, and examining it ti see what adjustments need to be made so that observed data matches expectations. After adjustments are made (either by uploading calibration data to the spacecraft or adjusting ground processing software), the process is repeated until calibration is attained.
During this time, the received data is not suitable for scientific use.
And after that, it’s not really suitable for public consumption.
Scientists want data that they can plug in to create graphs and stuff. The public wants pretty pictures. While JWST technically is taking pictures, the raw data that it creates would not be something the average Joe could do much with.
Someone has to actually take the data, and turn it into pretty pictures before it’s something the public has much use for.
It’s now about 2 weeks into the instrument calibration, and none of the tests
have been marked as completed.
At this rate it’s going to take about 8 months … !
I wouldn’t pay much attention to the accuracy of the website reports. But, further to my earlier post about one of JWST’s approved missions with respect to Trappist-1, the need for fine calibration is well illustrated by the following:
It’s going to do an analysis of the absorption spectrum of the atmosphere on each of the three planets in that star’s habitable zone, to find out what gases the atmosphere is comprised of. It’s going to do this on planets that are 39.46 light-years away! That’s about 229 trillion miles. At the typical speed of an earth-orbiting spacecraft, 17,500 mph, it would take about 1.5 million years to get there. Yet the JWST is (hopefully) going to be to peer into those planets’ atmospheres! Think about it!
As far as pretty pictures are concerned, I’d much rather read a report about the spectroscopic results and what exobiologists make of it.
Okay, so someone has to take the data to make pretty graphs as well.
My point was that the public has very little use for the raw data. It needs some form of processing or analysis before it it means anything to anyone without a bunch of letters after their name.
I wasn’t trying to argue with you – I was just saying that a scientific paper with results and informed speculation about that particular topic would be fascinating! And yes, I realize it will take a fair amount of time to get all that together.
Fair, I was more talking to those who are impatient for JWST to start returning science. It will be some time between when the data is gathered and when anyone publishes a paper. Sometimes the raw data for different observations have been made publically available, sometimes it is exclusive to a particular project for a period of time. (all of it is eventually made public, I believe.)
Yes, much speculation has been made about what we will find, and what we think we may find would mean. It would add quite a bit of weight, one way or the other, to debates about life in the universe.
Sad but true. I guess I am one of those folks without a bunch of letters after my name. Yes, I’m eager to see pretty pictures, but when I asked if they’d start doing science soon, I guess what I probably should have been asking is when will scientists be processing all that raw data and putting it into a dumbed down form that even I can understand.
I don’t know that I can give specific timelines, I’ve looked myself, and it’s hard to say, but, at worst, this time next year we should be swimming in pictures and graphs.
More realistically, I’d say we have some interesting and useful results within the next few months.
You don’t need to conduct and publish an entire study to start sharing some (probably false color) images that came from the telescope. Those will start coming soon after the telescope starts taking them, after they figure out how to best process the images to capture the public’s imagination.
And that’s something that there are people working at NASA for. It’s called “EPO”, or “education and public outreach”. I mean, raw Hubble data wouldn’t have been very glamorous, either, but we’ve all seen plenty of spectacular public imagery from it.
NASA rules are that all data must be released to the public at most one year after it’s collected. Some research groups have even more generous policies, including sometimes a policy that all data is public as soon as it’s received from the spacecraft.
And how long it varies to go from data to publication can vary tremendously. Sometimes, all the legwork is done already, and once the data is available, some grad student just needs to plug in in to the ready-and-waiting analysis program, and gets results five minutes later (at least, if nothing too unexpected happens). Sometimes, someone digs up 50 or 100-year-old data in some dusty archive somewhere, and comes up with a new way to look at it.
I’m not disparaging the pretty pictures, they are what gets the taxpayers to fund such instruments that allow people with lots of degrees to do science.
And I like to see them too. Sure, the actual data that gets used in studies is what is really answering the questions that we have about the universe, but most of us aren’t going to get a big poster of a scientific paper and put it on our wall.
I agree that the main value of JWST will be the science, the observations of space and the measurements of phenomena no instrument has been able to see before.
The pictures are a bonus, but an important bonus. They reassure a tax-paying public that we’re getting something worthwhile for the significant outlay of time, effort, and money.
I could see NASA selecting a small set of imagery accumulated during the calibration campaign and releasing them for that reason, but they would never do so in a way that interferes (even slightly) with getting cal/val done and dusted. It’s a critical path schedule item and the entire operational mission is on hold until it’s wrapped up.
I don’t know that the pictures will be any more spectacular than Hubble’s. The angular resolution of JWST is about the same as Hubble’s. The larger JWST mirror just compensates for the longer wavelengths it’s looking at.
The real prizes from JWST will be looking back earlier in the universe, looking through dust clouds at star formation, and for me getting atmospheric spectra from many of the nearest known planets. It would be amazing if we found life signatures, but even if we don’t we will be able to start cataloguing different atmospheres and help us understand how they form and how different they can be.
I suspect the next generation of optical ground-based telescopes will provide more amazing pretty pictures than JWST. With adaptive optics current large telescopes are already better than Hubble in terms of resolving power. The next generation will dwarf them. JWST’s segmented mirror is 6.5m in Diameter. We are building a ground based telescope now with a 30m mirror.
I am also hopeful that if Starship flies and lowers costs we will see Luvoir-A refunded. That is a giant space telescope that dwarfs JWST and will be able to directly image the closest exoplanets. If JWST finds a planet with an oxygen atmosphere or signs of unnatural pollutants, that may move up the urgency for a scope that can image them. But Luvoir isn’t supposed to fly until 2039, so I may not live to see it.
Based on what I’ve seen and heard so far, the main advantage is that JWST is so much bigger than the previous telescopes that focused on the infrared spectrum. There’s about a 2-minute segment on this video that talks about that.
Yeah, for sure. The point is that you need a much bigger mirror to get the same angular resolution as Hubble but in the mid and low infrared range. This is due to the Rayleigh limit for angular resolution:
θ = 1.22 * λ / d
Where θ = λ is the wavelength of the light and d is the diameter of the mirror. Therefore, if the wavelength increases towards the infrared, the same mirror has decreasing resolving power. JWST will have the same resolving power as Hubble, but in the infrared range. That’s oretty awesome, but it won’t mean we see smaller objects or more detail than Hubble did. We will just see the same thing in regions where Hubble couldn’t go, and the much smaller Spitzer and WISE did:
