Using the different Hubble Deep fields astronomers were able to study young galaxies in the early Universe and the most distant primeval galaxies. The different deep fields are also a good gathering grounds to find the most distant objects ever observed. The idea for the Hubble Deep Fields originated in results from the first deep images taken after the repair in These images showed many galaxies, which were often quite unlike those we see in the local Universe and could not otherwise be studied using conventional ground-based telescopes.
The resulting image consisted of separate exposures, with a total exposure time of more than hours, compared with typical Hubble exposures of a few hours.
The observed region of sky in Ursa Major was carefully selected to be as empty as possible so that Hubble would look far beyond the stars of our own Milky Way and out past nearby galaxies. The results were astonishing! Almost galaxies were seen in the image.
Scientists analysed the image statistically and found that the HDF had seen back to the very young Universe where the bulk of the galaxies had not, as yet, had time to form stars. These very remote galaxies also seemed to be smaller and more irregular than those nearer to us. This was taken as a clear indication that galaxies form by gravitational coalescence of smaller parts.
This time the field also contained a quasar, which was used as a cosmological lighthouse and provided valuable information about the matter between the quasar and the Earth. These impressive dips into the depths of space and time have allowed astronomers to glimpse the first steps of galaxy formation more than 10 billion years ago and are without doubt some of the great legacies of the Hubble Space Telescope.
After the Hubble observations of HDF-N and -S, other ground and space-based instruments targeted the same patches of sky for long periods. Some of the most interesting results seem to emerge from these fruitful synergies between instruments of different sizes, in different environments and with sensitivity to different wavelengths.
The Hubble Ultra Deep Field from represents the deepest portrait of the visible universe ever achieved by humankind. This is where the concept of the "observable universe" — the universe that we can see — comes into play. In 1 trillion to 2 trillion years, Livio said, this means that there will be galaxies that are beyond what we can see from Earth.
Hence, the definition of the observable universe. Galaxies also change over time. The Milky Way is on a collision course with the nearby Andromeda Galaxy , and both will merge in about 4 billion years.
Later on, other galaxies in our Local Group — the galaxies closest to us — will eventually combine. Residents of that future galaxy would have a much darker universe to observe, Livio said. They would probably not be able to tell there was a Big Bang.
As the early universe inflated, there are some theories that say that different "pockets" broke away and formed different universes. These different places could be expanding at different rates, include other types of matter, and have different physical laws than our own universe.
Livio pointed out there could be galaxies in these other universes — if they exist — but we have no way right now of knowing for sure. So the number of galaxies could even be greater than billion, when considering other universes. In our own cosmos, Livio said, astronomers will be better able to refine the number upon the launch of the James Webb Space Telescope for which his institute will manage the mission operations and science. Hubble is able to peer back at galaxies that formed about million years after the Big Bang.
After James Webb launches in , astronomers anticipate they can look as far back as million years after the Big Bang. While it is interesting to count the number of galaxies in our universe, astronomers are more interested in how galaxies reveal how the universe was formed. According to NASA, galaxies are a representation of how matter in the universe was organized — at least, on the large scale.
Scientists are also interested in particle types and quantum mechanics, on the small side of the spectrum. Because Webb can look back to the early days of the universe, its information will help scientists better understand the structures of the galaxies around us today.
Since its launch, Hubble Space Telescope has been dazzling the world with images of space and a deeper understanding of how the universe works. The Hubble Space Telescope remains one of the best telescopes in the world despite its age and only modest size.
Compared to the vast m telescopes built on the ground, with even larger ones planned in the future, the 2. However, it consistently outperforms many of the most advanced ground-based telescopes and is still considered the pinnacle of optical and ultraviolet astronomy, with demand for its use in research greatly exceeding the available observing time each year. Hubble travels at a speed of 17, mph and has covered a distance equivalent to a trip to Neptune, the furthermost planet in our solar system.
Hubble has peered back into the very distant past, to locations more than Since its mission began in , Hubble has made more than 1. Hubble's success is in no small part due to its position high above the atmosphere, removing many effects that hamper ground-based observers. In fact, ultraviolet astronomy is all but impossible to complete from the ground due to the presence of gases like ozone that block ultraviolet light in the upper atmosphere. Thanks to this and the lack of the turbulent air currents that make stars look like they are twinkling, Hubble is able to take some of the sharpest and deepest images of our Universe.
When Hubble shows us images in space, the view it gives us is always of how objects looked some time in the past. These attributes should allow it to see even further back and image those smaller, fainter first galaxies. Like the Hubble Deep Field, if all is in working order, adding those galaxies to the census should give us an even clearer picture of the whole.
Such research will undoubtedly cast even more light on cosmological questions about how the universe formed. All Rights Reserved. Singularity University is not a degree granting institution. Sign in. Forgot your password? Get help. Password recovery.
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