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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?"
Because NASA says that it costs too much to maintain, and it's getting close to its estimated end of life date.
CMDRTACO CHECK YOUR EMAIL!
So that the administration can turn NASA into a more pure multi-billion dollar yearly aerospace industry subsidy without a realistic programme or a significantly increased budget. NASA has always been an aerospace subsidy to some degree, but the Mars plan would probably double the portion of NASA's budget going directly into large aerospace companies for big ticket items, at the cost of stripping the science budgets clean.
Several extra billion dollars a year makes for a happy Boing and Lockheed, the real winners.
Braddock Gaskill
Uh, er, uh. No.
These images are seeing further than we've ever seen before because Hubble is using a more sensitive camera than the previous HDF. It's not because they sat on our butts for a few years and the 'horizon' expanded.
It's not broken, it's working fine. I don't know what the hell you're talking about, AFAIK ALL systems on the Hubble are working fine. The batteries are getting shot, they're the original ones.
There's equipment already built and in storage, or in process (was until the news came down) that would make the Hubble better than it ever has been, even though as it is now it's the best telescope we have in the optical range.
They want to scrap the Hubble because we need the money to maintain a space station that's nothing but a publicity stunt, and to fund research into a moon/mars mission that, much as I might wish they were real, will get scrapped as soon as the elections are over.
Also, the risk of a servicing mission is too great. Not the human risk, we're apparently perfectly willing to expend dozens of more spacewalk missions on finishing the ISS (which, again, isn't being used for what it was intended to be used for), but we can't risk one mission to work on the device which puts out more real science every week than the ISS ever has.
True, but the AREN'T PLANNING ANY. The only space telescope on the drawing board is the James Webb scope, and it's an IR scope. There's nothing even in the planning stages for a replacement for Hubble.
The truth is, the Hubble is still very capable, in fact more so than when it was launched. It needs new batteries and gyros, and as long as we're there, some new science instruments, and it'll keep going happily for a long time to come yet.
If new batteries and gyros are put on board, they'll last even longer; the new ones are capable of lasting far longer than the originals.
By current knowledge the spaceshuttle is "unsafe", because a very serious accident happened. But by current knowledge your car is "unsafe" too, because in all likelihood, very serious accidents happened with your (model/year) car too.
It's a mere matter of "acceptable risk" and "public opinion". If NASA decides the risk is "acceptable" and the "opinion" is that people would like to see Hubble repaired instead of chances reduced to 0% that there will happen an accident: Hubble will be repaired!
If one thinks of the future, with a more advanced spaceship, there will always be a risk that is accepted, and there will always be public opinion to make that risk a go or no go for launch.
I hope many people will see this picture, and wonder about the question: why not send the Space Shuttle back up now to safe Hubble, instead of waiting 10 years for who knows what ?
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As far as we understand it, there is no "edge" to the universe - at least not one we're expecting to ever be able to see. The universe as we know it has been around for about 13 billion years since the big bang. During that time, light has only been able to travel a certain distance - 13 billion light years (there are some technicalities with the fact that the universe is expanding as the light is traveling, but that's the gist). So we don't expect to ever be able to see farther than that distance, and most theories predict that the universe inflates (expands really fast) early in its life and so is actually much bigger than that distance. So if there is an edge, it's so far away light hasn't had the chance to get here from there. However, we can't even see that far. Earlier in the universe's history, it was much hotter and denser. Until about 300,000 years after the big bang, it was so hot and dense that it was opaque to light - light from before that epoch isn't able to travel very far without scattering, and can't reach our eyes. We can, however, see the last light that was released from the hot, dense gas just as the universe became transparent - this is seen as the cosmic microwave background. After that, the universe was very dark and homogenous - there were no stars or galaxies, and hence nothing for us to see! This period is called the "dark ages", for obvious reasons. After some hundreds of millions of years, gravity caused gas to clump together enough to produce the first stars and galaxies. These are the earliest things (other than the microwave background) that we could hope to study in a telescope picture. Some theories suggest that these might be weird objects - supermassive stars a hundred times bigger than our sun, bizzare protogalaxies, etc. - and they'll definitely teach us a lot about how galaxies form. So it's not the "edge", but it's probably quite near the edge of what we'll ever see.
Well, duh; first off, we're dealing with digital photography. There is no 'real/true colour', it's all composites anyway. Secondly, if you where to see only the visible light spectrum, there wouldn't be much to see.
-- Waht? Tehr's a preveiw buottn?
Also, I have never heard NASA say that the Hubble is just old and worn out. They say it's too risky to go up for another servicing mission.
It's not too risky. They could do it if they wanted to. They'd simply have to recertify the shuttles specifically to do it, and what they're saying is that the excess cost to do that is not worth the limited science that Hubble would do in the remaining years it has left.
In other words, Hubble is too expensive to keep running. That makes it uneconomical now.
The main problem with the controversy is that there are emotions involved, and that makes for very bad decision-making. Any of the advocates for Hubble always push the emotional attachment to Hubble, rather than the simple by-the-numbers math.
The optical is boring and scientifically uninteresting? Sorry, but you're just plain wrong! Sure, maybe you can't see the most red-shifted "foo" galaxy, but with STIS (the Space Telescope Imaging Spectrograph) we can obtain optical/near UV spectra which contain an enormous number of ionised metal transitions. This gives us a heap of information about things like the formation of the milky way, the interiors of white dwarves and many other things. Also, the oversubscription rate of hubble gives a good indication on how valuable scientists think it is.
:-) But then, what is scientifically interesting is a matter partially of opinion and partially of what's "in vogue". Ten years ago nobody cared much about stars or the solar system. Now the stellar crowd is close to finding the first stars formed in the milky way (population III stars) and the solar system kids are in big demand because they know how planets work (extra-solar planets anyone?).
Of course, I'm completely biased in that part of my Phd work is based on STIS work
As a cynical thought on JWST, don't underestimate the capacity for de-scoping the mission. It's happened already and is biting big projects (especially space-based ones) quite a bit in recent times. But maybe I'm just too pessismistic...
$AUS0.02
For press release images, it is true that they are not all that explicit about the details of the image processing. However, you are absolutely wrong that an image of this quality could be produced by a ground-based telescope. The atmosphere blurs out the light from distant objects and blocks some kinds of light either partially or completely. Sure we apply some image processing routines to the images, but fundamentally there is more information contained in a Hubble image like this than there is in a ground-based image taken by the most powerful telescope on Earth (Keck). On the other hand, there are some things that Keck can do that Hubble can't.
I don't know why some /.'ers seem to think that Hubble is easily replaceable. It isn't. When Hubble's mission ends, some types of observations will be impossible to make with other current instruments.
1) SM4 was canceled due to cost, we believe SM4 can extend the useful life of Hubble 4 or 5 years. Not True! SM4 was canceled primarily due to safety reasons. Please remember this, SM4 was Not Canceled due to Cost!!
2) Hubble is in 100% working order. Not true! The gyros which point the telescope are slowly failing.
3) Adaptive Optics/Clever Image Processing/Ground based telescope are better than or equal to Hubble. Not completly true! AO can image single objects to better than hubble. But AO has poor field of view! For reference, the UDF images have a field of view of 180 arcseconds square. AO fails above, 30, and degrades quickly above a few. Worst, AO needs a bright star to work. There simply are not enough of these stars! I can't reference this, but experts in the field think that it will take 30 years to get to Hubble's level of performance with AO.
4) Finally, AO will never work in at UV or near/mid IR wavelengths.
I am an astronomer, and I feel it is my duty to inform the public about the benefits of Hubble. HST serves a unique roll to the community. We should all understand exactly what the risk will be to fly SM4 before we lose 4 years of Hubble!