- 3170 - HUBBLE - deep field discoveries? The Hubble Space Telescope was launched in 1990. It weighed 22,500 pounds, 14 feet in diameter, 43 feet long, and orbits at 300 miles elevation. In 1993 a 94 inch mirror was repaired to solve some resolution problems. Cost of the program was $1,400,000,000 dollars.
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- Hubble can look back in time to 700,000,000 years after the Big Bang. Shortly after the Big Bang there was the Radiation Era when the Universe was nothing but energy. Then things expanded and cooled into the Dark Ages when matter was formed but it was ionized and so hot with particles vibrating and hitting each other the no light could escape.
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- Further expansion and cooling allowed the first atoms of hydrogen and helium to form. Then light could escape. Then the first stars formed when gravity pulled hydrogen gas together. Then the first galaxies when gravity pulled stars together, then we reach the time and space where Hubble Deep Field can begin to see.
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- What Hubble saw was a Universe of dwarf galaxies. Galaxies formed so quickly after only a billion years. The light reaching the Hubble mirror was 13,00,000,000 years old. The light photons trickled into the camera lens at the rate of one photon per minute.
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- These pjotons started they journey before Earth even existed. ( For comparison photons form nearby galaxies arrive at the rate of millions per minute). The field of view was 10% the size of a full moon, yet the image contained over 10,000 galaxies.
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- The telescope was looking at a spot in space in the constellation Fornax in the southern sky. This constellation is south, below the constellation Orion, for us northern hemisphere folks.
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- The time exposure to look at this spot in space was 1,000,000 seconds, or 11.3 days.(800 exposures between September 24 and January 16, 2004) It took that long to collect enough photons to make an image on the camera. Hubble can do something the eye cannot do. It’s charge coupled devices, CCD’s, can accumulate photons over time. Hubble was staring at the same spot for 400 orbits in order to get a picture.
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- The light traveled so far that it experienced the expansion of the Universe, the stretching of space, causing the stretch the wavelength of the light. The light was no longer visible light but infrared radiation.
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- So the camera had to be sensitive to infrared below the range of visible light. The wavelengths were stretched from 7 to 12 times the original light wavelengths. This amount of redshift corresponds to an age of the Universe of 400 to 800 million years old.
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- Some period slightly before that time galaxies were first formed. Prior to that period stars were first formed. Prior to that the Universe was 300,000 years old and we enter the Dark Ages. After 300,000 years of expansion the Universe cooled to 3000 Kelvin and ionized particles first began to combine into neutral atoms of hydrogen and helium.
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- Once this neutral environment was realized the photons of light could escape into space. Today, we see this light stretched out to the microwave frequency range, 2.4 gigahertz, called the Cosmic Background Radiation. This radiation has cooled down to 2.7 Kelvin, just a couple degrees above absolute zero temperature.
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- Hubble’s camera resolution was down to .08 arc seconds. Ground based telescopes have a resolution of 0.8 arc seconds, ten times less resolution. Hubble could see 10,000 galaxies in this narrow, deep view.
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- The galaxies were all shapes, sizes, and colors. Many were oddball shapes, nothing like the majestic spiral or elliptical galaxies we are accustomed to seeing. The oddball galaxies come from a time in universal history that was chaotic, with order and structure still forming.
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- The Swift space telescope and ground based telescopes recorded a supernova gamma ray burst with a redshift of 6.29 corresponding to a distance of 13,000,000,000 light years. The burst lasted for 200 seconds. This supernova explosion must have occurred in this same distribution of galaxies seen in the Hubble Deep Field. It released the energy equivalent to all the energy that could be released from our Sun over its entire 10 billion year lifetime. It must have been the formation of a massive blackhole to create such power.
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- New studies of long-lived radioactive elements, uranium-238 and thorium-232 in the stars of our Milky Way have allowed astronomers to determine its age to be at least 12,500,000,000 years old. When the big Bang occurred 13,700,000,000 years ago the only elements in the Universe were hydrogen, helium, and a little lithium.
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- Stars must have formed relatively quickly to create these higher level elements. If you measure these same elements in a meteorite you get the age to be 4,500,000,000 years, the age of our Sun and its solar system.
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- So our Milky Way galaxy is 91% as old as the Universe. And, our solar system was started when the Milky Way galaxy was 64% of its current age.
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- Humanoids arrived when the Earth was 99.92% of its current age. Hubble only cost us 10 cents pre light year of discovery. I would say the knowledge is worth the price.
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- Hubble Deep Field showed us a sliver of the early universe, from long before our sun was born. This is a three-dimensional picture, a cosmic core sample. The results are a treasure trove: 3,000 galaxies, large and small, shapely and amorphous, burning in the depths of space.
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- There are a few foreground stars, many remote galaxies and more galaxies in between. The galaxies vary in shape, size and color. We can see how they changed through time. With the Hubble Deep Field, we reach back nearly to the time when galaxies emerged from the chaos of the big bang.
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- In subsequent years, Hubble teamed with other observatories to examine small patches of the sky in high resolution with long exposures and multiple wavelengths. Surveys like the Hubble Ultra Deep Field (HUDF), and the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDLES) have provided pictures of vast, deep collections of galaxies, including some that existed when the universe was less than a billion years old.
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- In 2014, astronomers released the most colorful and comprehensive picture of the evolving universe ever captured by Hubble. The observation, called the Ultraviolet Coverage of the Hubble Ultra Deep Field, provides the missing link in star formation. Astronomers previously studied the Hubble Ultra Deep Field (HUDF) in visible and near-infrared light in a series of images captured from 2003 to 2009.
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- Now, using ultraviolet light, astronomers combined the full range of colors available to Hubble, stretching all the way from ultraviolet to near-infrared light. Ultraviolet light comes from the hottest, largest and youngest stars. By observing at these wavelengths, researchers get a direct look at which galaxies are forming stars and where the stars are forming within those galaxies.
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- Studying the ultraviolet images of galaxies in this intermediate time period enables astronomers to understand how galaxies grew in size by forming small collections of very hot stars. Because Earth’s atmosphere filters most ultraviolet light, this work can only be accomplished with a space-based telescope.
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- The resulting image made from 841 orbits of telescope viewing time contains approximately 10,000 galaxies, extending back in time to within a few hundred million years of the big bang.
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- Hubble can see even farther back in time by using gravitational lensing to find more distant galaxies that formed even earlier in the universe, such as in the CLASH survey and Frontier Fields. With its powerful infrared vision, the James Webb Space Telescope will see even farther back in time. -------------------- Other reviews available:
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- 2814 - HUBBLE - tests to detect exoplanets life? Astronomers have been using a variety of ground- and space-based telescopes to analyze how the ingredients of Earth's atmosphere look from space, using our planet as a proxy for studying extrasolar planets' atmospheres. They hope to eventually compare Earth's atmospheric composition with those of other worlds to note similarities and differences.
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- 2736 - HUBBLE - 30 years of astronomy? - The Hubble Space Telescope launched on the 24th of April, 30 years ago. One of the primary reasons for the Hubble telescope’s longevity is that it can be serviced and improved with new observational instruments through Space Shuttle visits.
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- 1770 - The Hubble Space Telescope is celebrating 25 years of space astronomy. One of its greatest discoveries in 1998 was that gravitational attraction of all the matter in the Universe was not causing cosmic expansion to slow down. Quite the opposite, Hubble’s view of the most distant supernovae explosions confirmed that cosmic expansion was accelerating
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- 1179 - What has Hubble Taught Us? The Hubble Space Telescope has been sending us astronomical images for over 20 years. The telescope was launched in the Discovery Space Shuttle in April, 1990. Astronomers have been studying Hubble’s images, and the data that created them, and have written over 7,000 scientific papers to date. Let’s look at some of the discoveries that have been made by this telescope orbiting the Earth.
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- 1173 - The Hubble Deep Field space telescope image is one of the most amazing discoveries in all of astronomy. The space telescope stares at a single, small spot in the darkest part of the sky. It stares for the longest time to get the longest time exposure and to collect photons that are as faint as possible.
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- 1047 - The Hubble Space Telescope took its pictures using a very long time exposure lasting 10 days or more. The Hubble camera used CCD’s, charge coupled devices, that can collect photons over that entire time of exposure. Our eyes can not do this. Photons fire nerve cells in the back of our eyes and send the image to the brain. We do not have the ability to collect the photons until the image gets bright enough to see. The Hubble camera has much greater sensitivity and can see very faint objects accumulating photons over a long period of time. Faint objects are very far away and strange things happen while the light is traveling those distances.
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- 857 - Hubble Deep Field Discoveries. Everyone has heard of and seen images of the Hubble Deep Field. These images were created by the Hubble Space Telescope staring at a single spot in the sky and taking a very long time exposure picture. If you missed it go to Sky in Google Earth to get the picture.
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- 772 - Hubble Space Telescope. This is the 17th anniversary of the Hubble Space Telescope. It was launched April 24, 1990. I have collected some 8 3-ring binders, full of Hubble pictures. The discoveries using Hubble’s instruments have made astronomy and physics a frontier of amazement for me.
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- May 24, 2021 HUBBLE - deep field discoveries? 606 3170
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