Written Information: As you enter text, the area will expand. Make sure to check the required details of the assignment and review the rubric (see document links) to self-assess your work. Your paragraphs will be in block format, enter one return between paragraphs. The tab key, indent feature will not appear when typing directly into the wiki page.
Roughly a 10th the width of the Milky Way, the star-packed discovery confirms that a period of rapid star birth unfolded in the era after the Big Bang, which took place about 13.75 billion years ago.
"The nighttime sky would have looked very different then," says study lead author Rychard Bouwens of the University of California-Santa Cruz.
Massive blue stars created by dense clouds of hydrogen gas would have been born and died within millions of years' time, quick by cosmic standards, their death blasts filling space with charged, radioactive particles.
Newly installed instruments aboard the Hubble Space Telescope
A better look at the era of the first stars will most likely come from NASA's troubled James Webb Space Telescope, which the space agency announced late last year was about $1.5 billion over budget, pointing to a total cost of $6.5 billion and a 2015 launch.
Once launched, the bigger mirrors and near-infrared spectrum sensitivity of the James Webb Space Telescope should allow a full survey of the first galaxies, now established as ripe for observation by Hubble's latest discovery.
Galaxies are the vast islands of stars filling space. Our own spiral-shaped Milky Way, parts of which can be seen on clear nights streaking across the heavens, contains hundreds of billions of stars.
"They are big, they're sharp-edged, and they contain a lot of energy," says astrophysicist Douglas Finkbeiner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. The twin gamma-ray-emitting bubbles each stretch 25,000 light-years from the center of the galaxy's top and bottom (a light-year is about 5.9 trillion miles).
Galaxies are the islands of stars filling the cosmos. Large ones such as our own Milky Way galaxy span more than 100,000 light-years (nearly 600,000 trillion miles) and contain hundreds of billions of stars.
The few faint earliest galaxies that emerge from the survey of about 7,500 galaxies are much smaller and filled with young, massive stars. They shine from only 600 million to 800 million years after the Big Bang, which took place about 13.7 billion years ago.
"These are the seeds of later large galaxies like our own," says astronomer Garth Illingworth of the University of California-Santa Cruz, speaking at the American Astronomical Society meeting. Filled with blue-tinted stars, these early galaxies are only one-twentieth the diameter and have just 1% of the mass of our own galaxy and later ones seen in the Great Observatories Origins Deep Survey panorama
Scientists used to believe that the Milky Way Galaxy was smaller than its neighbor the Andromeda Galaxy. "The Andromeda Galaxy was called the 'big sister' and the Milky Way was the 'little sister'" an astronomer at the Harvard-Smithsonian Center for Astrophysics. But a new study shows that the galaxies are about the same size. Galaxies are large collections of stars, gases, and dust bound together by gravity. Visuals
Make sure to include the location of your image; add a caption with this information
A whirlpool galaxy.
A spiral galaxy
Image of "Cylinder Galaxy"
A cartwheel galaxy
The Milky Way is part of acluster of galaxies called the Local Group.
Topic: Research Focus What is your topic? My topic is galaxies State the focus of your research: What it is, how it looks, and how it forms. Notes
Include notes, statistics and facts that you will use to write your final paper. You may want to label sections of your notes to help you be more organized as you write. As you take notes from a source, you should list the source citation in the Works Cited section above.
A galaxy is a very large group of stars or planets. A galaxy contains a huge number of stars.
These stars all move around a center of gravity. Gravity is the pull between objects. This center is called the nucleus. In the nucleus, billions of stars are very close together. These stars are so close, they look like one bright circle of light.
Scientists think there are more than 100 billion galaxies in the universe. Each galaxy contains billions of stars.
Earth is part of a galaxy called the Milky Way. The Milky Way looks like a bright band of light in the sky. This white light looks like milk. That is how it got its name. The Milky Way is shaped like a spiral.
Every star we see at night is part of the Milky Way galaxy. The sun is part of the Milky Way, too. There are more than 200 billion stars in the Milky Way.
Most galaxies are in groups. Some groups are large. Some groups are small. There is nothing but empty space between the galaxies.
Galaxies come in three different shapes. Some are round, or elliptical. Some are spirals. Some are odd shapes.
Galaxies are important. They help scientists measure the size of the universe. They also help scientists learn how old the universe is. There is still a lot we do not know about galaxies. Scientists keep studying these star groups to learn more about our universe.
A galaxy is a very large group of stars or planets. Galaxies contain a huge number of stars. All these stars move around a center of gravity. Gravity is the pull between objects. This center is called the nucleus. In the nucleus, billions of stars are very close together. These stars are so close, they look like one bright circle of light.
Everything in space is part of the universe. The universe holds billions of stars and planets. It holds billions of galaxies, too. Scientists think there are more than 100 billion galaxies in the universe. Each galaxy contains billions of stars.
The Milky Way
Earth is part of a galaxy called the Milky Way. The Milky Way looks like a bright band of light in the sky. Because this white light looks like milk, people named it the Milky Way.
Every star we see at night is part of the Milky Way galaxy. The sun is part of the Milky Way, too. There are more than 200 billion stars in the Milky Way.
Scientists who study stars are called astronomers. Astronomers think that the Milky Way is shaped liked a spiral. However, they are not really sure. Since Earth is inside the Milky Way, no one can really see what this galaxy looks like. An astronomer would have to travel far into space to see the Milky Way.
Galaxy Groups and Types
Most galaxies are in groups. Some groups are large, and some groups are small. There is nothing but empty space between the galaxies.
Galaxies come in three different shapes. Some are round, or elliptical. These galaxies are the most common. Elliptical galaxies are small and dim, so they are hard to see.
Spiral galaxies are shaped like pinwheels. These galaxies contain both old stars and new stars.
The last group of galaxies is called irregular. These galaxies have odd shapes. There are large amounts of gas and dust in irregular galaxies. There are two irregular galaxies that are close to the Milky Way. Someday, astronomers think they might join the Milky Way. Then they will all be part of one huge galaxy.
Studying Galaxies
Galaxies are important. They help scientists measure the size of the universe. They also help scientists learn how old the universe is. The distance between galaxies is so large that astronomers measure it in light-years. A light-year is the distance light travels through space in one year. That is about six trillion miles. It takes many light-years for light to travel between galaxies. If a galaxy is ten billion light-years away, that means it took ten billion years for its light to travel to Earth.
Galaxies can teach us a lot about space. But there is still a lot we do not know about galaxies. Scientists keep studying these star groups to learn more about our universe.
The history of galaxy discovery is also the history of advances in the telescope. About 150 c.e., Claudius Ptolemy catalogued the heavens as seen with the unaided eye, listing several patches of "misty" light in the sky. After inventing the astronomical telescope in 1609, Galileo observed that the largest misty patch, the Milky Way, consists of millions of stars. In fact, the Milky Way is the galaxy that contains our Sun. William Herschel used his much bigger telescope starting in 1783 to study thousands of misty patches, which are called nebulas (from Latin for "clouds"). Herschel guessed that some "nebulas" might actually be like the Milky Way, islands of stars too far away for his telescope to distinguish individually.
In 1845, William Parsons, the Earl of Rosse [English: 1800-1867], built the largest telescope to that date with which he observed that some misty patches have the shape of a spiral. About 20 years later, William Huggins [English: 1824-1910] found that light from one of these spirals, a large patch in Andromeda, matches light emitted by stars and not light emitted by glowing gas, even though the telescope that Huggins used was too weak to detect individual stars.
Astronomers argued over whether the spirals were part of the Milky Way or farther away. In 1908, Henrietta Leavitt found a new way to measure distances to stars. Her methods showed that 2 large misty patches that good telescopes revealed as collections of stars, the Magellanic Clouds, are outside the Milky Way. Edwin Hubble in 1924 used Leavitt's method with a new large telescope to show that spirals are far outside the Milky Way. The distant islands of stars, surrounded by vast amounts of empty space, were christened "galaxies," from the Greek name for the Milky Way. Hubble identified three major classes of galaxies: spirals like Andromeda and the Milky Way; irregular galaxies like the Magellanic Clouds; and balls of stars called elliptical galaxies.
Galaxies are linked into groups called clusters, which contain dozens or hundreds of galaxies. The clusters group into large regions of hundreds of clusters, called superclusters. Regions between the superclusters, called voids, have few or no galaxies.
How old are the objects you can see in the sky? The brightest star in the night sky, Sirius, is believed to be about 200-300 million years old. The Sun and Moon are much older--about 4.5 billion years old.
New pictures taken by a telescope in space show ancient galaxies that blow those numbers away. Some of these images show galaxies that are about 13 billion years old. The universe itself is only about 13.7 billion years old, so these galaxies formed when the universe was very young.
Garth Illingworth, an astronomer at the University of California, Santa Cruz, is part of one team that studied the ancient galaxies in the pictures. "We are looking back 13 billion years and seeing galaxies just 600 to 700 million years after the Big Bang, when the Universe was like a 4-year-old," he says.
The pictures came from the Hubble Space Telescope, which floats through space around the Earth, 353 miles up. For 19 years, this orbiting telescope has been beaming pictures of deep space back to astronomers, who study the information to learn more about the universe and our place in it.
Three teams of scientists studied the pictures. All three teams found that the most distant reaches of space have fewer bright galaxies than closer regions. This dropoff in the number of galaxies was not surprising, based on what astronomers have already learned about the universe. To look deep into space is the same as looking back in time, because light from faraway galaxies takes a long time to reach Earth. When astronomers look at a picture of a distant star or galaxy, they are seeing light that took billions of years to travel to Earth. So when scientists look at these new pictures of distant galaxies, they see the star or galaxy as it looked millions or billions of years ago, at a time when the first galaxies were just forming.
To take these pictures, the telescope used a new tool called the Wide Field Camera 3, or WFC3. Astronauts installed this camera on the telescope in May of this year during a repair mission. Like an ordinary camera, this one takes pictures using visible light. But in addition, it also records snapshots at wavelengths the eye can not see, including ultraviolet light and infrared light
Researchers are excited about the WFC3, which is more sophisticated than earlier cameras on board the Hubble. "This is a golden moment," says Richard Ellis of Caltech in Pasadena, who also studied the pictures.
All of the galaxies in these pictures showed up in a tiny area of the sky. This slice of sky is so small that 150 pieces the same size would fit into the apparent size of a full moon. Because this slice of the sky is so small and the WFC3 just started taking pictures this summer, the scientists say they're not sure that they'll find similar galaxies in every direction.
But they do believe the WFC3 will give scientists some very interesting information about the early universe. "This is a very exciting time," says Ellis.
POWER WORDS (adapted from the Yahoo! Kids Dictionary)
billion: 1,000,000,000, or 1,000 million
galaxy: A collection of stars, gas and dust that make up the universe. A galaxy contains an average of 100 billion solar masses (or 100 billion times the weight of the sun) and ranges in diameter from 1,500 to 300,000 light-years.
infrared radiation: The range of invisible radiation wavelengths from about 750 nanometers to 1 millimeter, on the border of the microwave region.
ultraviolet radiation: The range of invisible radiation wavelengths from about 4 nanometers, on the border of the x-ray region, to about 380 nanometers, just beyond the violet in the visible spectrum.
telescope: An arrangement of lenses or mirrors or both that gathers visible light, permitting direct observation or photographic recording of distant objects.
Andromeda Galaxy, cataloged as M31 and NGC 224, the closest large galaxy to the Milky Way and the only one visible to the naked eye in the Northern Hemisphere. It is also known as the Great Nebula in Andromeda. It is 2.2 million light-years away and is part of the local group of several galaxies that includes the Milky Way, which it resembles in shape and composition. It has a diameter of about 165,000 light-years and contains at least 200 billion stars. Its two brightest companion galaxies are M32 and M110. The light arriving at earth from the Andromeda Galaxy is shifted toward the blue end of the spectrum, whereas the light from all other cosmic sources exhibits red shift.
Local group, in astronomy, loose cluster of at least 19 nearby galaxies, including our own Milky Way galaxy, the Andromeda Galaxy, and the Magellanic Clouds. The local group is spread over an ellipsoidal region of space with a major axis of approximately 3 million light-years. The Milky Way galaxy, near one end of the major axis, and the Andromeda Galaxy, near the other end of the dick, are the largest dfciq1aet huaOP of the group. Two galaxies in the group were detected only recently by their infrared radiation; a dusty region in space obscures their visible light. There may be other galaxies in the local group that are as yet undetected. As shown by the work of G. de Vaucouleurs, the local group is part of a supercluster containing at least 50 separate clusters, each having from a few dozen to as many as a thousand galaxies. These groups appear to be concentrated in a plane, which indicates that the supercluster is rotating. Its center lies approximately 50 million light-years away in the direction of the constellation Virgo
Magellanic Clouds, two galaxies located in the far southern sky and visible to the unaided eye; they are classified as irregular because they show no definite symmetry or nucleus. The larger of the two, known as the Large Magellanic Cloud (LMC), is located mostly in the constellation Dorado; its angular diameter measures approximately 7°. The Small Cloud (SMC) is almost completely in the constellation Tucana, and measures approx. 4° in diameter. Both are nearly 160,000 light-years from the earth. They are part of the local group of galaxiesQ, which includes our own galaxy and the Andromeda Galaxy, and are the nearest extragalactic objects. The Magellanic Clouds, named for the PortuguesHWe navigator Magellan, were first studied in detail by Sir John Herschel in the 19th cent. While studying Cepheid variable stars in the SMC, Henrietta Leavitt discovered (1912) the period-luminosity relation. This relation offered a technique for measuring the distances of stars and galaxies. In Feb., 1987, Supernova 1987A erupted in the LMC. The first supernova visible without a telescope since 1604, this star gradually brightened over the next few months and remains under careful observation as it fades. The diffuse nebulae in both the LMC and the SMC appear to have fewer "metals" (elements heavier than helium); the deficiency is much more pronounced in the SMC.
Andromeda is a constellation. A constellation is a group of stars. It can Wmed after a princess in Greek mythology. She was chained to a rock on the seashore. A hero named Perseus rescued her just as she was about Q%to be eaten by a sea monster.
The three largest stars in the constellation are named Alpheratz, Mirach, and Almaak. Alpheratz represents the head of Andromeda. Mirach is her waist and Alamak is her chained foot.
The most well-known object within the constellation is the Andromeda galaxy. A galaxy is a large group of stars, dust, and gas. On clear nights, the Andromeda galaxy can be seen without a telescope. Through a telescope, the Andromeda galaxy appears as a small, oval patch of light. It is larger and possibly brighter than the Milky Way galaxy.
=Q1 Getting Started
Project Documents:
Rubric:
Space Exploration Adventure Rubric.doc
- Details
- Download
- 32 KB
Space Exploration Adventure Rubric.pdf
- Details
- Download
- 49 KB
Written Information: As you enter text, the area will expand. Make sure to check the required details of the assignment and review the rubric (see document links) to self-assess your work. Your paragraphs will be in block format, enter one return between paragraphs. The tab key, indent feature will not appear when typing directly into the wiki page.
Roughly a 10th the width of the Milky Way, the star-packed discovery confirms that a period of rapid star birth unfolded in the era after the Big Bang, which took place about 13.75 billion years ago.
"The nighttime sky would have looked very different then," says study lead author Rychard Bouwens of the University of California-Santa Cruz.
Massive blue stars created by dense clouds of hydrogen gas would have been born and died within millions of years' time, quick by cosmic standards, their death blasts filling space with charged, radioactive particles.
Newly installed instruments aboard the Hubble Space Telescope
A better look at the era of the first stars will most likely come from NASA's troubled James Webb Space Telescope, which the space agency announced late last year was about $1.5 billion over budget, pointing to a total cost of $6.5 billion and a 2015 launch.
Once launched, the bigger mirrors and near-infrared spectrum sensitivity of the James Webb Space Telescope should allow a full survey of the first galaxies, now established as ripe for observation by Hubble's latest discovery.
Galaxies are the vast islands of stars filling space. Our own spiral-shaped Milky Way, parts of which can be seen on clear nights streaking across the heavens, contains hundreds of billions of stars.
"They are big, they're sharp-edged, and they contain a lot of energy," says astrophysicist Douglas Finkbeiner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. The twin gamma-ray-emitting bubbles each stretch 25,000 light-years from the center of the galaxy's top and bottom (a light-year is about 5.9 trillion miles).
Galaxies are the islands of stars filling the cosmos. Large ones such as our own Milky Way galaxy span more than 100,000 light-years (nearly 600,000 trillion miles) and contain hundreds of billions of stars.
The few faint earliest galaxies that emerge from the survey of about 7,500 galaxies are much smaller and filled with young, massive stars. They shine from only 600 million to 800 million years after the Big Bang, which took place about 13.7 billion years ago.
"These are the seeds of later large galaxies like our own," says astronomer Garth Illingworth of the University of California-Santa Cruz, speaking at the American Astronomical Society meeting. Filled with blue-tinted stars, these early galaxies are only one-twentieth the diameter and have just 1% of the mass of our own galaxy and later ones seen in the Great Observatories Origins Deep Survey panorama
Scientists used to believe that the Milky Way Galaxy was smaller than its neighbor the Andromeda Galaxy. "The Andromeda Galaxy was called the 'big sister' and the Milky Way was the 'little sister'" an astronomer at the Harvard-Smithsonian Center for Astrophysics. But a new study shows that the galaxies are about the same size. Galaxies are large collections of stars, gases, and dust bound together by gravity.
Visuals
Make sure to include the location of your image; add a caption with this information
A whirlpool galaxy.
A spiral galaxy
A cartwheel galaxy
The Milky Way is part of acluster of galaxies called the Local Group.
Works Cited
Sources: Include the source information for all of the magazine articles, reference sources (encyclopedias) and web site pages that were used to complete your project. The source information for encyclopedias may be found at the end or beginning of each entry in iCONN. When using periodicals, the publication information will be at the beginning or end of the article. This needs to be formatted for MLA standards. If it is not labeled 'Source Citation' it can be formatted appropriately by using EasyBib.com. You should use EasyBib for the web sites. The final Works Cited should be listed in alphabetical order by the first word of the source citation.
Sample:
"Milky Way." Kids InfoBits Presents: Astronomy. Gale, 2008. Reproduced in Kids InfoBits. Detroit: Gale, 2012.
"The Milky Way." WMAP's Universe. NASA, 28 June 2010. Web. 06 Mar. 2012. <http://map.gsfc.nasa.gov/universe/rel_milkyway.html>.
Vergano, Dan. "Galaxy Bracketed by Big Bubbles." USA Today 10 Nov. 2010: 05A. Web. 6 Mar. 2012.
Your Source List:
1.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=6&searchTerm=Galaxies&ste=6&tbst=tsrch&tab=1&docNum=BX3200950607&bConts=39
2.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=7&searchTerm=Galaxies&ste=6&tbst=tsrch&tab=1&docNum=BX3200950590&bConts=39
3.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=5&searchTerm=Galaxies&ste=6&tbst=tsrch&tab=1&docNum=BX3200520113&bConts=39
4.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&vrsn=127&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=7&searchTerm=Galaxies&ste=8&tbst=tsrch&tab=2&docNum=A212120371&bConts=39
5.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=4&searchTerm=Galaxies&ste=6&tbst=tsrch&tab=1&docNum=BX3201100888&bConts=39
6.http://galenet.galegroup.com/servlet/KidsInfoBits?subTopic=Space%2B%2526%2BAstronomy&locID=s0002&failover=0&srchtp=topic&topic=Science%2B%2526%2BMath&c=4&searchTerm=Galaxies&ste=10&tbst=tsrch&tab=4&docNum=CJ215900027&bConts=39
Topic: Research Focus
What is your topic? My topic is galaxies
State the focus of your research: What it is, how it looks, and how it forms.
Notes
A galaxy is a very large group of stars or planets. A galaxy contains a huge number of stars.
These stars all move around a center of gravity. Gravity is the pull between objects. This center is called the nucleus. In the nucleus, billions of stars are very close together. These stars are so close, they look like one bright circle of light.
Scientists think there are more than 100 billion galaxies in the universe. Each galaxy contains billions of stars.
Earth is part of a galaxy called the Milky Way. The Milky Way looks like a bright band of light in the sky. This white light looks like milk. That is how it got its name. The Milky Way is shaped like a spiral.
Every star we see at night is part of the Milky Way galaxy. The sun is part of the Milky Way, too. There are more than 200 billion stars in the Milky Way.
Most galaxies are in groups. Some groups are large. Some groups are small. There is nothing but empty space between the galaxies.
Galaxies come in three different shapes. Some are round, or elliptical. Some are spirals. Some are odd shapes.
Galaxies are important. They help scientists measure the size of the universe. They also help scientists learn how old the universe is. There is still a lot we do not know about galaxies. Scientists keep studying these star groups to learn more about our universe.
A galaxy is a very large group of stars or planets. Galaxies contain a huge number of stars. All these stars move around a center of gravity. Gravity is the pull between objects. This center is called the nucleus. In the nucleus, billions of stars are very close together. These stars are so close, they look like one bright circle of light.
Everything in space is part of the universe. The universe holds billions of stars and planets. It holds billions of galaxies, too. Scientists think there are more than 100 billion galaxies in the universe. Each galaxy contains billions of stars.
The Milky Way
Earth is part of a galaxy called the Milky Way. The Milky Way looks like a bright band of light in the sky. Because this white light looks like milk, people named it the Milky Way.
Every star we see at night is part of the Milky Way galaxy. The sun is part of the Milky Way, too. There are more than 200 billion stars in the Milky Way.
Scientists who study stars are called astronomers. Astronomers think that the Milky Way is shaped liked a spiral. However, they are not really sure. Since Earth is inside the Milky Way, no one can really see what this galaxy looks like. An astronomer would have to travel far into space to see the Milky Way.
Galaxy Groups and Types
Most galaxies are in groups. Some groups are large, and some groups are small. There is nothing but empty space between the galaxies.
Galaxies come in three different shapes. Some are round, or elliptical. These galaxies are the most common. Elliptical galaxies are small and dim, so they are hard to see.
Spiral galaxies are shaped like pinwheels. These galaxies contain both old stars and new stars.
The last group of galaxies is called irregular. These galaxies have odd shapes. There are large amounts of gas and dust in irregular galaxies. There are two irregular galaxies that are close to the Milky Way. Someday, astronomers think they might join the Milky Way. Then they will all be part of one huge galaxy.
Studying Galaxies
Galaxies are important. They help scientists measure the size of the universe. They also help scientists learn how old the universe is. The distance between galaxies is so large that astronomers measure it in light-years. A light-year is the distance light travels through space in one year. That is about six trillion miles. It takes many light-years for light to travel between galaxies. If a galaxy is ten billion light-years away, that means it took ten billion years for its light to travel to Earth.
Galaxies can teach us a lot about space. But there is still a lot we do not know about galaxies. Scientists keep studying these star groups to learn more about our universe.
The history of galaxy discovery is also the history of advances in the telescope. About 150 c.e., Claudius Ptolemy catalogued the heavens as seen with the unaided eye, listing several patches of "misty" light in the sky. After inventing the astronomical telescope in 1609, Galileo observed that the largest misty patch, the Milky Way, consists of millions of stars. In fact, the Milky Way is the galaxy that contains our Sun. William Herschel used his much bigger telescope starting in 1783 to study thousands of misty patches, which are called nebulas (from Latin for "clouds"). Herschel guessed that some "nebulas" might actually be like the Milky Way, islands of stars too far away for his telescope to distinguish individually.
In 1845, William Parsons, the Earl of Rosse [English: 1800-1867], built the largest telescope to that date with which he observed that some misty patches have the shape of a spiral. About 20 years later, William Huggins [English: 1824-1910] found that light from one of these spirals, a large patch in Andromeda, matches light emitted by stars and not light emitted by glowing gas, even though the telescope that Huggins used was too weak to detect individual stars.
Astronomers argued over whether the spirals were part of the Milky Way or farther away. In 1908, Henrietta Leavitt found a new way to measure distances to stars. Her methods showed that 2 large misty patches that good telescopes revealed as collections of stars, the Magellanic Clouds, are outside the Milky Way. Edwin Hubble in 1924 used Leavitt's method with a new large telescope to show that spirals are far outside the Milky Way. The distant islands of stars, surrounded by vast amounts of empty space, were christened "galaxies," from the Greek name for the Milky Way. Hubble identified three major classes of galaxies: spirals like Andromeda and the Milky Way; irregular galaxies like the Magellanic Clouds; and balls of stars called elliptical galaxies.
Galaxies are linked into groups called clusters, which contain dozens or hundreds of galaxies. The clusters group into large regions of hundreds of clusters, called superclusters. Regions between the superclusters, called voids, have few or no galaxies.
How old are the objects you can see in the sky? The brightest star in the night sky, Sirius, is believed to be about 200-300 million years old. The Sun and Moon are much older--about 4.5 billion years old.
New pictures taken by a telescope in space show ancient galaxies that blow those numbers away. Some of these images show galaxies that are about 13 billion years old. The universe itself is only about 13.7 billion years old, so these galaxies formed when the universe was very young.
Garth Illingworth, an astronomer at the University of California, Santa Cruz, is part of one team that studied the ancient galaxies in the pictures. "We are looking back 13 billion years and seeing galaxies just 600 to 700 million years after the Big Bang, when the Universe was like a 4-year-old," he says.
The pictures came from the Hubble Space Telescope, which floats through space around the Earth, 353 miles up. For 19 years, this orbiting telescope has been beaming pictures of deep space back to astronomers, who study the information to learn more about the universe and our place in it.
Three teams of scientists studied the pictures. All three teams found that the most distant reaches of space have fewer bright galaxies than closer regions. This dropoff in the number of galaxies was not surprising, based on what astronomers have already learned about the universe. To look deep into space is the same as looking back in time, because light from faraway galaxies takes a long time to reach Earth. When astronomers look at a picture of a distant star or galaxy, they are seeing light that took billions of years to travel to Earth. So when scientists look at these new pictures of distant galaxies, they see the star or galaxy as it looked millions or billions of years ago, at a time when the first galaxies were just forming.
To take these pictures, the telescope used a new tool called the Wide Field Camera 3, or WFC3. Astronauts installed this camera on the telescope in May of this year during a repair mission. Like an ordinary camera, this one takes pictures using visible light. But in addition, it also records snapshots at wavelengths the eye can not see, including ultraviolet light and infrared light
Researchers are excited about the WFC3, which is more sophisticated than earlier cameras on board the Hubble. "This is a golden moment," says Richard Ellis of Caltech in Pasadena, who also studied the pictures.
All of the galaxies in these pictures showed up in a tiny area of the sky. This slice of sky is so small that 150 pieces the same size would fit into the apparent size of a full moon. Because this slice of the sky is so small and the WFC3 just started taking pictures this summer, the scientists say they're not sure that they'll find similar galaxies in every direction.
But they do believe the WFC3 will give scientists some very interesting information about the early universe. "This is a very exciting time," says Ellis.
POWER WORDS (adapted from the Yahoo! Kids Dictionary)
billion: 1,000,000,000, or 1,000 million
galaxy: A collection of stars, gas and dust that make up the universe. A galaxy contains an average of 100 billion solar masses (or 100 billion times the weight of the sun) and ranges in diameter from 1,500 to 300,000 light-years.
infrared radiation: The range of invisible radiation wavelengths from about 750 nanometers to 1 millimeter, on the border of the microwave region.
ultraviolet radiation: The range of invisible radiation wavelengths from about 4 nanometers, on the border of the x-ray region, to about 380 nanometers, just beyond the violet in the visible spectrum.
telescope: An arrangement of lenses or mirrors or both that gathers visible light, permitting direct observation or photographic recording of distant objects.
Andromeda Galaxy, cataloged as M31 and NGC 224, the closest large galaxy to the Milky Way and the only one visible to the naked eye in the Northern Hemisphere. It is also known as the Great Nebula in Andromeda. It is 2.2 million light-years away and is part of the local group of several galaxies that includes the Milky Way, which it resembles in shape and composition. It has a diameter of about 165,000 light-years and contains at least 200 billion stars. Its two brightest companion galaxies are M32 and M110. The light arriving at earth from the Andromeda Galaxy is shifted toward the blue end of the spectrum, whereas the light from all other cosmic sources exhibits red shift.
Local group, in astronomy, loose cluster of at least 19 nearby galaxies, including our own Milky Way galaxy, the Andromeda Galaxy, and the Magellanic Clouds. The local group is spread over an ellipsoidal region of space with a major axis of approximately 3 million light-years. The Milky Way galaxy, near one end of the major axis, and the Andromeda Galaxy, near the other end of the dick, are the largest dfciq1aet huaOP of the group. Two galaxies in the group were detected only recently by their infrared radiation; a dusty region in space obscures their visible light. There may be other galaxies in the local group that are as yet undetected. As shown by the work of G. de Vaucouleurs, the local group is part of a supercluster containing at least 50 separate clusters, each having from a few dozen to as many as a thousand galaxies. These groups appear to be concentrated in a plane, which indicates that the supercluster is rotating. Its center lies approximately 50 million light-years away in the direction of the constellation Virgo
Magellanic Clouds, two galaxies located in the far southern sky and visible to the unaided eye; they are classified as irregular because they show no definite symmetry or nucleus. The larger of the two, known as the Large Magellanic Cloud (LMC), is located mostly in the constellation Dorado; its angular diameter measures approximately 7°. The Small Cloud (SMC) is almost completely in the constellation Tucana, and measures approx. 4° in diameter. Both are nearly 160,000 light-years from the earth. They are part of the local group of galaxiesQ, which includes our own galaxy and the Andromeda Galaxy, and are the nearest extragalactic objects. The Magellanic Clouds, named for the PortuguesHWe navigator Magellan, were first studied in detail by Sir John Herschel in the 19th cent. While studying Cepheid variable stars in the SMC, Henrietta Leavitt discovered (1912) the period-luminosity relation. This relation offered a technique for measuring the distances of stars and galaxies. In Feb., 1987, Supernova 1987A erupted in the LMC. The first supernova visible without a telescope since 1604, this star gradually brightened over the next few months and remains under careful observation as it fades. The diffuse nebulae in both the LMC and the SMC appear to have fewer "metals" (elements heavier than helium); the deficiency is much more pronounced in the SMC.
Andromeda is a constellation. A constellation is a group of stars. It can Wmed after a princess in Greek mythology. She was chained to a rock on the seashore. A hero named Perseus rescued her just as she was about Q%to be eaten by a sea monster.
The three largest stars in the constellation are named Alpheratz, Mirach, and Almaak. Alpheratz represents the head of Andromeda. Mirach is her waist and Alamak is her chained foot.
The most well-known object within the constellation is the Andromeda galaxy. A galaxy is a large group of stars, dust, and gas. On clear nights, the Andromeda galaxy can be seen without a telescope. Through a telescope, the Andromeda galaxy appears as a small, oval patch of light. It is larger and possibly brighter than the Milky Way galaxy.