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Hubble Space Telescope's Sixteenth Anniversary
An anonymous reader writes "This week marks the sixteenth anniversary of the launch of Hubble Space Telescope. 'To celebrate [...] NASA and the European Space Agency (ESA), are releasing this image of the magnificent starburst galaxy, Messier 82 (M82). This mosaic image is the sharpest wide-angle view ever obtained of M82. The galaxy is remarkable for its bright blue disk, webs of shredded clouds, and fiery-looking plumes of glowing hydrogen blasting out of its central regions.' Wired News also has some nice additional images."
... Is NASA policy NEVER mentioning the industrial contractors whose engineers designed and whose techs actually build the damn this in their press releases.
;-)
I used to work for the company that built Hubble (at the time called TRW, now NGST), and it was considered (from within) one of their greatest achivements in the civilian/scientific spacecraft...
If you google now for "TRW Hubble" you'll find a whole bunch of articles mentioning that TRW was selected to build JWST, "Hubble replacement", but not too many mentioning that we did actually built the original Hubble. But it could be google's fault, after all!
Paul B.
P.S. I had absolutely NOTHING to do with that program, but it still makes me sad for the guys who did.
Yes, indeed.
And M82 is truly a bad example of what the Hubble can really do.
Why?
Because you can get a picture of M82 from the ground just as well
as the Hubble does. See here for example.
The true advantage of the Hubble can be realized when you are looking at
a smaller object, like V838 Mon or the finer details of the Helix Nebula.
They read this stuff at seminary, and are aware of the issue.
Because you can get a picture of M82 from the ground just as well as the Hubble does.
Your example (866x972) hardly compares to the massive 9500x7400 pixel hubble image, which has fewer artefacts and far more background detail, but I agree that the ultra deep field image is way cooler, and also quite impossible to take without a space telescope.
A witty
you must not understand anything about this then if that is your idea. The Hubble will be a burnt core streaming into the ocean before ANY of that can happen.
You ask a few good questions that merit a longer answer.
First of all, it is important to note that Einstein, in his theory of general relativity, showed that space can be curved. It is only because of this that one can even talk about something like the "diameter" of the universe. In simple GR, and using some fairly broad assumptions about the properties of the universe, there are three principal "shapes" for the universe: the universe can have a "positive curvature" and a finite volume, it can have an infinite volume and be "flat", or it can have a "negative curvature" and an infinite volume.
In three dimensions, these spaces are very difficult to imagine for us humans, but a 2d analogy might make things clearer: The analogy in 2d for a positively curved space is the surface of a sphere, for a flat space it is a plane, and for a negatively curved space a hyperboloid, and the "volume" would be the respective surface area. Note that locally, e.g., for small ants living on a huge sphere (or humans living on the Earth), it is very difficult to distinguish between these three possibilities. For example, it took 1000s of years for humans to realize that the Earth was not a flat disk, just because our Earth is so tremendously big that in our everyday life, its curvature just does not matter to us (unless you are an airline pilot that is...).
In the past 20-30 years, we were able to develop methods that allowed us to infer in what type of universe we live. Essentially, these methods boil down to measuring the amount of gravitating stuff in the universe, which is summarized in a parameter we astronomers call "Omega". If Omega<1, the universe is infinite and open (has an infinite volume), for Omega equals 1 it is flat and open, and for Omega>1 it has a finite volume.
Several measurements, using the Hubble Space Telescope, the Wilkinson Microwave Anisotropy Probe, X-ray data from galaxy clusters measured with ROSAT, XMM-Newton, and Chandra, data taken with balloon experiments etc. have allowed us to build what is called the so-called concordance model of cosmology, i.e. the baseline model that most of the astronomicical community agrees with. This model has an age of around 14 billion years and has Omega=1. This means that in this model the universe is flat and infinite in size. Therefore, giving the "diameter" of the universe for the concordance model, as quoted by the original poster, does not make sense in this model.
Now, astronomers often are sloppy people, and this is especially true for the people who write press releases for NASA, because they have the incredibly difficult job to summarize a piece of very complicated physics in a 1-2 minute sound bite. What is often meant when you read something like "the universe is 100billion light years across" is a statement about that part of the universe that is visible to us. So, consider a photon that was emitted shortly after the big bang. This photon happily moves through space for about 14 billion years, and is eventually detected by us. So, the distance traveled by the photon was 14 billion light years. However, while the photon traveled, the Universe expanded, i.e., it increased in volume. This means that the distance that the source of light has from us now is much larger. It is this distance which is often quoted as the "size of the universe". How far it is depends on the model assumptions one makes, i.e., the expansion history of the universe, but one can get values which are much larger than cT, where c is the speed of light and T the age of the universe.
So much for my very simplified answer of what proves to be far more complicated questions than one might think. I hope it clarified matters a little bit, if you want a little bit more detail, a good WWW page to check out is Ned Wright's cosmology tutorial (http://www.astro.ucla.edu/~wright/cosmo_03.htm).
Space had been expanding whilst the photos are in transit:
http://en.wikipedia.org/wiki/Cosmic_light_horizon
"The weirdest thing about a mind, is that every answer that you find, is the basis of a brand new cliche" -
You can always downsample the 9500 x 7400 full-res version.