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Hubble's Deepest Pictures Yet
MrBook2 writes "NASA have just released the Ultra Deep Field (UDF). This image took 800 exposures and clocked in at 11.3 days (!) of exposure time. This image is deeper than the Hubble Deep Field which has yielded a vast amount of knowledge. So, why exactly was it that NASA wanted to scrap the Hubble?"
APOD had an old Hubble picture of the same space location earlier today. Unfortunately I didn't save it back then. Can someone please upload it so we can compare to the old depth of field?
So, why exactly was it that NASA wanted to scrap the Hubble?
Because thanks to adaptive optics, it is now possible to get very close to hubble's resolution with Earth-based telescopes. Thus, it is much, much cheaper to use those ground-based scopes.
Because we don't have a really huge budget for this sort of thing, and all the money that goes into Hubble could be used on a newer, better space based scope.
http://astrobio.net/news/print.php?sid=835
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It goes back to an era quite a bit earlier than the earlier deep-fields--about 400 and 800 million years after the big bang--and they are noticing quite a bit more chaos in the early universe, as the first galaxies were forming:
So, they are already seeing oddball things that they didn't see in earlier deep-field images.
The image as presented is actually a composite of two images, one taken in visible light and one taken in near-infrared. This allows the image to show details that would have normally been obscurred by dust.
HCG 50a = 2MASX J11170638+5455016
11h17m06.4s +54d55m02s
Actually, a congressman from Colorado is trying to get a commitee together to determine the fate of the Hubble, so the decision is not solely on the director of NASA. This could mean life for the Hubble.
I submitted the 'save the hubble' story a couple days ago and was turned down.
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
They are not scrapping Hubble because of cost. The NASA Administrator stated that the reason was due to "the risk to the astronauts on a Hubble mission and President Bush's plans to send humans to the moon, Mars and beyond as the reason for NASA's change of focus." In fact, the planned upgrade has been built, tested and (most importantly) PAID FOR. It's just setting there waiting to be taking to the telescope and installed.
Are you Corn Fed?
The big reason I have heard for discontinuing mantanence on the Hubble is it's orbit. If a shuttle goes out to do maintanence and is damaged, the orbit makes it impossible to reach the ISS and difficult to do anything else to save the crew.
This signiture copied from somewhere.
http://savethehubble.org/
If they are willing to take the risk to finish ISS, there is no good reason not to fix Hubble.
Write your congressman.
Blaze a trail to the New World
NASA intends to eventually replace the Hubble with the James Webb Space Telescope:
The James Webb Space Telescope (JWST) is an orbiting infrared observatory that will take the place of the Hubble Space Telescope at the end of this decade. It will study the Universe at the important but previously unobserved epoch of galaxy formation. It will peer through dust to witness the birth of stars and planetary systems similar to our own. And using JWST, scientists hope to get a better understanding of the intriguing dark matter problem. The JWST is also a key element in NASA's Origins Program. So, between the JWST and the terrestrial observatories using new adaptive optic technologies, over the long haul it makes better sense to re-allocate our scarce space resources not only on these projects, but also towards the new goals announced by GWB. Remember that Bush hardly increased NASA's budget, so they cannot afford to do everything at once.
More facts about the JWST as it stands now.
Proposed Launch Date: August 2011
Proposed Launch Vehicle: Ariane 5
Mission Duration: 5 - 10 years
Total payload mass: Approx 6200 kg, including observatory, on-orbit consumables and launch vehicle adaptor.
Diameter of primary Mirror: ~6.5 m (21.3 ft)
Clear aperture of primary Mirror: 25 m2
Primary mirror material: beryllium
Mass of primary mirror: about one-third as much as Hubble's
Focal length: TBD
Number of primary mirror segments: 18
Optical resolution: ~0.1 arc-seconds
Wavelength coverage: 0.6 - 28 microns
Size of sun shield: ~22 m x 10 m (72 ft x 33 ft)
Orbit: 1.5 million km from Earth at L2 Point
Operating Temperature: Cost: $824.8 million
Note that it is planned to launch the JWST using an Arianne rocket, which is far cheaper, and can also get the device to the L2 point. Yes, the shuttle could launch JWST into LEO (low earth orbit) but it would then have to travel up on an additional rocket. Seems like they have accounted for this and are going to use a cheaper expendable vehicle to do the job.
You have a short memory.
The mirror is seriously messed up. It has been corrected with a lens, but the quality is still rather less than it should have had.
The James Webb scope will have a much larger mirror, much faster camera, could be put on an orbit to allow evacuating the shuttle crew to Fred, and perhaps not have the problem of failing gyros every year or so.
1) quite possibly. Jury is still out.
2) No. Big bang is still the best bet and universe definitely appears to be finite (which doesn't mean there is a boundary or edge, just that it doesn't go on forever).
3) Yes, space curves back on itself. That is the only way to have a boundless finite universe.
References:
Physics 110 cosmology FAQ
No Edge, No Centre
Will better images ever show the edge of the universe?
How old is the universe? Finite or infinite? Have an edge?
$#!^ happens, but why does it always have to happen to me???
The one problem with that is that the JWST is an infrared and near infrared telescope. 0.6 micron = 600 nm = red light. This won't give any coverage to the rest of the optical spectrum (~380-600 nm).
You have a short memory.
Well, his still considerably better than this AC's.
The mirror is seriously messed up. It has been corrected with a lens, but the quality is still rather less than it should have had.
And, yet, still better than anything else we have today or will have in the next 20 years. There is no Hubble replacement on the way, and while earth based scopes can replace some of its functionality, they can't replace all of it.
The James Webb scope will have a much larger mirror, much faster camera
And is an IR only telescope. It does not have the range of instruments that Hubble has. In particular, it lacks any realistic UV sensors.
could be put on an orbit to allow evacuating the shuttle crew to Fred
I'm not even going to try and guess what "Fred" is, but JW isn't going to be in an orbit allowing the shuttle to do anything with. The JW Scope is going to be stationed at the L2 point, considerably farther than where the shuttle can go. If something goes wrong with the scope -- thank you for playing, goodnight. It's unserviceable, at least by anything we have now or in the forseeable future. Damn well better not have a problem with failing gyros, mirror irregularities, or anything else. Because if it does then we've put all our eggs in one basket. By the time that JW is launched and in position (late 2010 to 2012) Hubble will be unrepairable. Unless we spend the time, money, and risk on a single shuttle mission to repair and upgrade it.
The "edge" is defined by frequency redshifting of infinity, where objects are receding at the apparent speed of light, and the universe is infinitely small. The largest redshifts observed last month are an eleven-fold frequency stretch (z=10). Visible light is stretched into deep infra-red. This implies an apparent doppler recession of 98% the speed of light (without including the cosmological constant or acceleration). It gets harder and harder to observe objects as they are more red-shifted.
The fact that galaxies get "slapped together so quickly" is actually a rather good piece of the evidence for the existence of dark matter. The amount of visible matter in an ordinary galaxy (or galaxy cluster - most of these simulations are actually done with clusters and not individual galaxies) would actually take quite a bit longer to form than what we observe. These objects form because the occasional bit of the gas in the universe is slightly more dense than the neighboring bits, and that clump will tend to attract other bits by gravity and grow. The growth rate gets faster as the clump gets bigger (and hence exerts a stronger gravitational pull). We can get an idea of the size of the original "clumps" in the gas by looking at the patters of hot and cold spots in the cosmic microwave background (the leftover "heat" of the early universe), and they're not big enough for galaxies and clusters to form so quickly. Here's where dark matter comes in. If there's extra "stuff" in the universe that isn't visible, then galaxies are actually a lot heftier than they seem and are able to grow much faster. There's a lot more to it than that, but this is the basic idea.
NASA doesn't want to scrap the Hubble. They have to scrap the Hubble. Really it boils down to $$ and resources. Their funding is being cut severely and they have to choose which projects to keep going. With the Hubble costing them $$ in new parts and shuttle visits for maintenance, cutting it has the highest impact.
Well, there's spam egg sausage and spam, that's not got much spam in it.
This is BS. The latest and best estimate of the age of the universe is from the WMAP data, which gave a result of 13.7 billion years. This was actually close to the lower (more recent) end of generally accepted estimates. Neither the original Hubble Deep Field nor this image has had any significant effect on estimates of the time of the Big Bang.
You can argue all you please about how Hubble is out-of-date and needs cancellation, but the real experts will disagree with you. Astronomers are quite irate about the Hubble's cancellation, and rightly so. Politicians should not dictate how NASA spends its paltry budget - and doubly so in an election year when your poll numbers are looking grim.
Sean O'Keefe was picked for the head of NASA precisely because he has a reputation as a budget cutter. The man knows *nothing* about space science.
But don't take my word for this. The American Astronomical Society - an organization that includes essentially all the professional astronomers in America, and rarely if ever takes a political stand - released a statement pleading to reconsider the cancellation:
AAS's cancellation statement
I believe there's a statement from the UK's Royal Astronomical Society there, too.
Argh! What are you talking about? We know how far away the "edge" of the Universe is! The only context in which the question makes sense is if by "Universe" we mean the observable Universe, which is simply a sphere centered on us, with radius c*T, where T is the elapsed time between the epoch of recombination and now, which was just a few hundred thousand years after the Big Bang. So T=13.7 Gyr +/- 10%.
1) The universe is a lot older than we thought
No, no one who knows the first thing about cosmology entertains such a theory today.
2) There was no big bang, and space is infinite
Sorry, *all* applicable evidence points to a Big Bang as the origin of our Universe. Besides, the Big Bang does *NOT* preclude a physical Universe that is infinite in size! (here I am not talking about the observable Universe, whose finite geometry is well understood)
3) Space curves back on itself
If such curvature exists, its radius is much larger than that of the observable universe, so this has little to do with what you are talking about. The observable universe is very nearly flat.
Liberal (adj.): Free from bigotry; open to progress; tolerant of others.
Yes, hubble and JWST are complementary, but it's not strictly true to say that hubble is the only UV tool around. FUSE - the Far UV Spectroscopic Explorer, has been up there and operating since 1999, run by johns hopkins (literally across the street from STScI).
It has a bit of life left in it, but covers the Far-UV, while STIS aboard hubble covers the near UV. So between FUSE, hubble and JWST, you get continuous (spectroscopic) coverage from the FarUV to the IR.
And it's hard to IR from the ground too, just like the UV.
The fact is, we're seeing 186,000 miles further every second, because light takes time to get places.
Ahhh, if only cosmology were that simple. In fact, due to the way space itself is expanding, and especially in light of the recent discoveries that the expansion continues to accelerate, our horizen is shrinking. Eventually we'll only be able to see our gravitationally bound local group... and if the "big rip" theories hold true (which I am skeptical about on other grounds but we'll see), eventually even those disappear.
You statement is only true in a static universe with a discrete beginning that lept into existence all at once (no 'expansion', just instant matter everywhere that eventually forms into galaxies); three wrong assumptions for the price of one.
This is absolutely 100% false. The Hubble UDF image was taken over the span of several months, not over 11.3 days of consecutive orbits. Stacking images from earthbound telescopes taken over several different days/months is a standard astronomical practice. No special equipment (i.e. a worldwide distributed network of telescopes) is required to do this.
As for not having the versatility of Hubble -- there are many terrestrial observatories that are far more versatile (and accessible!) than HST. It all depends on the sort of observing you're doing.
(2) The atmosphere blocks alot of the UV band, in particular the hydrogen 1 Lyman-alpha line. That's the brighest emission line of the most common element in the universe. With a wavelength of about 121.6nm (unredshifted), not much of it punches through the atmosphere. Check out this for a primer on what's so important about the lyman alpha line.
--- Often in error; never in doubt!
As for the next part, the great thing about telescopes is that the don't have to be identical to contribute to the same image. Any number of telescopes looking at the same object will contribute linearly in proportion to their mirror area. Telescopes have to account for the rotation of the earth all the time, even on exposures of just a few minutes. If you don't believe me, try taking a long exposure photograph of the night sky and you'll see a streaking effect of the stars. You can put these telescopes in arrays such as the two Keck 10m, and as long as you're looking at a stable object that's not going through rapid change, it doesn't matter when you take exposures. They could be weeks apart.
It gets even better though. We've constructed huge radio 'telescopes' as the VLA and VLBA which has elements in Hawaii and the eastern US. These are arrays of multiple dishes all pointing at the same object. A few number crunches later, the overall effect is our ability to observe insanely large wavelengths of light, wavelengths almost the size of earth! We're more cabable than you might think, and we most certainly have NOT lost any collective will, whatever that means.
Quid festinatio swallonis est aetherfuga inonusti?
Africus aut Europaeus?
It's a good thought, but ozone holes are really ozone depletions, and they still rule out sensitive UV measurement. That, and the holes are at the poles, and so you're limited to the amount of sky you can look at.
Dr Fish
Moderators need explain how your got rated a 4 for your silly reply.
Because JWST is an medium optical, near infrared, and far infrared telescope, not an IR scope as the parent said, and therefore it is informative?
NGST is most certainly not a replacement for Hubble.
It is in the deep-field category, which is where all the pretty-picture enthusiasts are pushing.
optical ground based adaptive optics catches on
Catches on? I think just about everyone agrees that optical AO is the obvious next step - hence the thirty-meter-telescope (TMT) and many other AO projects.
I'll agree with you that in the UV, Hubble doesn't have a match out there yet. But JWST doesn't serve a complimentary role to HST, it supersedes it in a lot of Hubble's operational capacity.
Honestly, with this servicing mission, how long do you think Hubble will last? 10 years? And how much will it cost? Considering they need to recertify the shuttles specifically to do this task, and have a backup shuttle ready in case something goes wrong... I don't think most people fully understand the excess cost that would need to go into it.
I'm not saying that Hubble isn't a good observatory. It is. What I'm saying is that scientists never expected Hubble to last forever, and they have planned past it (for crying out loud, there are conferences that are basically called "Life After Hubble").
Actually, if you look closely, the galaxies are all different colors. Look towards the lower right corner, and you will see an orange spiral galaxy, and then below and to the right of it, a smaller, redder one. The difference in color is because of the redshift. The most distant objects are the tiny, red pinpoints, much smaller than the large, obvious galaxies.
Please read some of the posts by astronomers (including me) in this story and any other HST story. This is absolutely untrue. Yes, AO does allow ground-based astronomers to take high angular resolution images comparable to the quality of Hubble. However, the science that you can get from AO images does not compare to the science you can get out of Hubble images. AO is still too limited in many ways, and there is no way it will ever overcome some of the limitations. THE FACT IS THAT ULTRAVIOLET ASTRONOMY IS IMPOSSIBLE FROM THE GROUND! No AO telescope can observe in the UV, which Hubble can. This makes impossible many topics in Quasar research, interstellar and intergalactic medium research, hot star research, and a zillion other fields that I can't think of off the top of my head.
Here's a little basic physics for you: when hydrogen ionizes and recombines, it emits photons at a discrete series of wavelengths known as the Lyman series. The brightest line is the H 1 Lyman alpha, at 121.6 nm -- the brightest line from the most common element (99%) in the universe. When redshifted, this line often ends up in blue band, where the JWST can't see. If you're wondering what it's useful for, just google for lyman alpha forest. On the other hand, don't bother -- you're quite happy with the opinions you have; why change them?
--- Often in error; never in doubt!
No. They are not. Your information is wrong. Check your sources.
We will be without a space observatory for at least 6 years before Icarus goes up. The Icarus program is fighting right now for funding that was cut do to the latest gulf war. Icarus also is fighting for funding that is now headed towards the vaporus human settlement on the moon and mars.
The loss of Hubble is a monumental loss of at least six years of cutting edge science and duplicated effort. Hubble proved the existence of black holes yet several million dollars of upgrade parts lie in storage in florida never to see the light of day, or space for that matter.
In short. What a waste.
I'm frankly appalled that someone with even a passing knowledge of astrophysics, much less a degree in the subject, would issue a blanket statement like "the optical is boring."
Yah, yah, I know. The post was something like 4 lines long - it wasn't intended to be in depth. I was actually saying that the optical is boring with reference to JWST, which is correct - JWST is a deep-field scope, and deep-field high-optical/UV isn't nearly as useful as deep/far infrared.
It was a bit of a short-tempered post because I hate it when people refer to the JWST as "just an" infrared telescope. It's not. It's optimized for infrared, definitely, but that's where big mirror, huge collection area, long integration times are most important, and that's what I was trying to say.
And what of the 9x oversubscription rate on HST itself? Do you honestly think all those observations, or even a large majority, are in the limited wavelength regime that NGST/JWST will have in common with HST?
I think a lot of them are. (Specifically I think that this one - the ultra deep field - is, and I'd be correct). I do agree that losing Hubble's UV is bad. I had hoped that the MIDEX AO wasn't pushed back, but I must've missed that - I knew others were.
I'm presuming you actually have a more nuanced view of the subject than your post would indicate
If you read it again, I said "the optical is boring" with reference to JWST. It wasn't as clear as I had hoped (it was clear to me, but then again, I wrote it).
we will have any sort of UV capability for the following ten years or so
No, I agree we won't. But unfortunately I don't think we'd get another 10 years out of Hubble, and then we'd be out of the UV anyway. I don't think it's worth wasting the equivalent of several MIDEX's worth of money to try to keep it running for an extra 4 or 5 years.
It was politics, ie Bush's men on mars initiative, that led to O'Keefe's decision to cancel Hubble's servicing mission. Let's not give up now that O'Keefe is starting to feel some political pressure. At http://SaveHubble.org we are working on polling all of congress. How about some of you slashdot readers give us a hand contacting them?
Yep, that's my sense too. Of course it would not be there if the corrective lenses didn't need to be there :-)
Truth be told, a researcher likely isn't bothered by the stuff, unless their object is near a brighter star. But I've already seen stylized artwork based on the famous "pillars of life" image that includes the halo! The public thinks that junk belongs there!!!!!!
Cheers