Why can the Hubble Space Telescope take such awesome pictures?
zed asked:
The pictures that I have seen look like really colorful dust. But they have pictures of galaxies
First of all, are they real?
Secondly, how do they know where to point the telescope? (Maybe a dumb question)
And Third, how can they take the pictures if the places are so far away???
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The pictures that I have seen look like really colorful dust. But they have pictures of galaxies
First of all, are they real?
Secondly, how do they know where to point the telescope? (Maybe a dumb question)
And Third, how can they take the pictures if the places are so far away???
September 3rd, 2009 at 1:01 am
Yes, the pictures are real, but they’re false color - Hubble takes black-and-white images on their digital cameras (that’s what the scientists need) and combine images taken in different filters to get the images you see, most of which are pretty close to the actual colors you’d get with a normal camera.
We know from surveys of the sky where most of the galaxies are, so Hubble is mostly looking at ones we already knew where there (the pictures they release to the public at least; the small faint fuzzy galaxies they image are probably only interesting to astronomers).
We can take pictures of things theoretically back to almost the beginning of time, it just took a really long time for the light to reach us.
September 3rd, 2009 at 10:43 pm
1) Yes, the images are real. However, the photos are often taken with light that human eyes can’t detect (for example, infrared or ultraviolent). So, the images are falsely colored, with ultraviolet appearing as blue, for example.
2) Space telescopes know their own approximate orientation by looking for bright stars. They can then maneuver themselves precisely using control moment gyroscopes (CMGs), sending data back to the ground. And if you want to take pictures of galaxies, it turns out it doesn’t matter what direction you’re looking. You will see thousands of galaxies in the tiniest view window with a long enough exposure time. For example, check out the ‘Hubble deep field’, an image which was exposed for something like 10 days.
3) Light travels until it hits something. A galaxy a billion light years away emitted light a billion years ago. That light is just reaching the Earth today. So, we see an image of what the galaxy looked like a billion years ago. Space telescopes are like time machines in that respect.
September 4th, 2009 at 10:42 am
The reason why the Hubble can take such wonderful shots is because it has superior optics and because it is in space so it has none of the Earth’s atmosphere to look through. Unobstructed views of everything. They are using the Hubble to look into places that humans have never been able to look at before so a lot of the shots contain new images for all of us.
September 5th, 2009 at 12:30 pm
The quality of images received from space telescopes is obtained since they are free from the distortions of chemicals and molecules in our atmosphere.
Space telescopes use a variety of sources throughout the EM spectrum. Visual light is almost always combined with x-ray and infrared imaging to obtain details not seen through visual imaging alone. It also can image ultraviolet light sources which our atmosphere blocks. Using this technology, space telescopes are able to peer through galaxies to ’see’ what is hidden by galactic dust.
Knowing that space telescopes are not hindered by our atmosphere, the highest quality optic technology goes into these telescopes which receive funding through NASA.
The images are real. The technological quality has allowed mankind to discover hundreds of thousands of new galaxies which were never before seen. Deep Space Hubble photographs are taken over several months. This is not something Earth-bound telescopes are able to do. This is what allows Hubble to take images of the farthest galaxies. Even imaging those galaxies which were just beginning to form almost 14 billion years ago.
Hubble can be pointed to any part of space via gyroscopes. NASA normally decides which areas of space to look at. Professional astronomers can receive time use of the Hubble to look at any area of space they want. NASA has occasional contests to increase public interest in space projects. In one, they allowed the public to choose where to point Hubble.
It is true that the images are black and white. Color is added to differentiate various chemical content or heat sources or filters to increase contrast and detail when desired. The visible light spectrum can be used but is not normally very interesting to look at in a photo.
September 7th, 2009 at 5:09 am
How could it take pictures of distant objects? You can derive the answer from its name,, it’s a telescope. And it can take such clear pictures because the atmosphere isn’t disturbing nor vibrating the incoming light from space to earth by its moving molecules, the telescope is actually behind the atmosphere, orbiting earth.
September 9th, 2009 at 12:35 pm
How the telescope works
“In orbit about 380 miles (610 kilometers) above the earth, the Hubble Space Telescope views the heavens without looking through the earth’s atmosphere. The atmosphere bends light due to a phenomenon known as diffraction, and the atmosphere is constantly moving. This combination of diffraction and movement causes starlight to jiggle about as it passes through the air, and so stars appear to twinkle. Twinkling blurs images seen through ground-based telescopes. Because an orbiting telescope is above the atmosphere, it can produce pictures in much finer detail than a ground-based telescope can.
This false-color image taken by the Hubble Space Telescope using infrared light shows Uranus’s rings and clouds. The different colors in the image represent different atmospheric conditions.
This false-color image taken by the Hubble Space Telescope using infrared light shows Uranus’s rings and clouds. The different colors in the image represent different atmospheric conditions. Image credit: NASA
The Hubble Space Telescope can also observe ultraviolet and infrared light that is blocked by the atmosphere. These forms of light, like visible light, are electromagnetic radiation. The wavelength (distance between successive wave crests) of ultraviolet light is shorter than that of visible light. Infrared light has longer wavelengths than visible light. Ultraviolet light comes from highly energetic processes, such as the formation of disks around black holes and exploding stars. Infrared light provides information about cooler, calmer events, such as the formation of dust clouds around new stars.
The United States space agency, the National Aeronautics and Space Administration (NASA), operates the Hubble Space Telescope in cooperation with the European Space Agency (ESA). The telescope is controlled by radio commands relayed from NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Astronomers tell the telescope where to point, and computer — driven instruments aboard the telescope record the resulting observations. The telescope transmits the data by radio to astronomers on the ground.
The Hubble Space Telescope has two kinds of instruments: (1) imagers, which take pictures; and (2) spectrographs, which analyze light. Imagers are electronic detectors called charge — coupled devices (CCD’s). The CCD’s convert light into electronic signals, which an on — board computer records and sends to the ground.
A spectrograph, like a prism, spreads light into its component colors, much as water droplets spread sunlight into a rainbow. The resulting band of light is called a spectrum (plural spectra). Using spectrographic data from the Hubble Space Telescope, astronomers can determine the composition of stars and galaxies–measuring, for example, the amounts of hydrogen, carbon, and other chemical elements in them. “
September 12th, 2009 at 8:34 pm
it takes awhile to get a good picture… it takes 1 million picture and then combines them to get the pictures we see. (number of pictures used to make up the main picture can vary bassed on the distance) however the main factor that makes its pictures great is the fact that its in space, this means that it doesnt have to deal with looking through our distorting atmosphere
September 13th, 2009 at 8:34 pm
1. Color from Hubble often enhanced by filters.
2. Awesome pictures because no atmosphere in space. Telescopes on ground have images warped by the atmosphere, pollution, etc. In space, no such problems.
3. Sometimes they don’t know where to point the telescope.
Open the link above.
That picture contains 3,000 galaxies. The Hubble Space Telescope took this picture by focusing on the darkest piece of space it could find. The piece of space is about the size of a grain of sand held at arms length.
Stop for a second and think about the enormity of the Universe. If you look into Space and focus on a piece of space the size of a single grain of sand, it contains 3,000 galaxies, EACH galaxy with 100 billion suns and 100 billion planets.
That is simply incomprehensible. Each piece of space the size of a grain of sand holds 3,000 galaxies. The Universe is so absolutely enormous the human mind cannot even begin to understand it’s size.
Needless to say, there is no way to see all the galaxies in a single picture. It’s pretty amazing the Hubble was able to see 3,000 of them in one picture.
Hubble is in the process of being replaced by more powerful space telescopes that can see ALMOST to the beginning of the Universe…..but not the Big Bang.
September 14th, 2009 at 11:29 am
Hubble can take awesome images because:
1) It has no atmosphere to hinder it. Earth’s atmosphere induces so much distortion in what we see that wipes out much of the detail that Hubble is able to capture. If we had no atmosphere on earth we would be able to capture the same images.
2) The CCD chips are specially cooled to keep them from over heating during long exposures.
3) Photographic processing techniques have improved over the years enabling scientists and engineers to glean more data from the data collected by the CCD’s.
Yes, many image are “false” images in that colors have been added to black and white photos to enhance elemental qualities for research purposes. The shots still look great and are release to the public with the “False color image” label. However, many of Hubble’s stunning pictures are not false color image rather they are true color images and are just as stunning as the false color images.