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How much weight would the Milky Way weigh if the Milky Way could be weighed?

By Ashley Strickland, CNN

Updated 12:53 PM ET, Thu March 7, 2019

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Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image.
Photos: Wonders of the universe
Galaxy NGC 4485 collided with its larger galactic neighbor NGC 4490 millions of years ago, leading to the creation of new stars seen in the right side of the image.
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Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang.
Photos: Wonders of the universe
Astronomers developed a mosaic of the distant universe, called the Hubble Legacy Field, that documents 16 years of observations from the Hubble Space Telescope. The image contains 200,000 galaxies that stretch back through 13.3 billion years of time to just 500 million years after the Big Bang.
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A ground-based telescope's view of the Large Magellanic Cloud, a neighboring galaxy of our Milky Way. The inset was taken by the Hubble Space Telescope and shows one of the star clusters in the galaxy.
Photos: Wonders of the universe
A ground-based telescope's view of the Large Magellanic Cloud, a neighboring galaxy of our Milky Way. The inset was taken by the Hubble Space Telescope and shows one of the star clusters in the galaxy.
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One of the brightest planetary nebulae on the sky and first discovered in 1878, nebula NGC 7027 can be seen toward the constellation of the Swan.
Photos: Wonders of the universe
One of the brightest planetary nebulae on the sky and first discovered in 1878, nebula NGC 7027 can be seen toward the constellation of the Swan.
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The asteroid 6478 Gault is seen with the NASA/ESA Hubble Space Telescope, showing two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. The bright streaks surrounding the asteroid are background stars. The Gault asteroid is located 214 million miles from the Sun, between the orbits of Mars and Jupiter.
Photos: Wonders of the universe
The asteroid 6478 Gault is seen with the NASA/ESA Hubble Space Telescope, showing two narrow, comet-like tails of debris that tell us that the asteroid is slowly undergoing self-destruction. The bright streaks surrounding the asteroid are background stars. The Gault asteroid is located 214 million miles from the Sun, between the orbits of Mars and Jupiter.
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The ghostly shell in this image is a supernova, and the glowing trail leading away from it is a pulsar.
Photos: Wonders of the universe
The ghostly shell in this image is a supernova, and the glowing trail leading away from it is a pulsar.
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Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula.
Photos: Wonders of the universe
Hidden in one of the darkest corners of the Orion constellation, this Cosmic Bat is spreading its hazy wings through interstellar space two thousand light-years away. It is illuminated by the young stars nestled in its core — despite being shrouded by opaque clouds of dust, their bright rays still illuminate the nebula.
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In this illustration, several dust rings circle the sun. These rings form when planets' gravities tug dust grains into orbit around the sun. Recently, scientists have detected a dust ring at Mercury's orbit. Others hypothesize the source of Venus' dust ring is a group of never-before-detected co-orbital asteroids.
Photos: Wonders of the universe
In this illustration, several dust rings circle the sun. These rings form when planets' gravities tug dust grains into orbit around the sun. Recently, scientists have detected a dust ring at Mercury's orbit. Others hypothesize the source of Venus' dust ring is a group of never-before-detected co-orbital asteroids.
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This is an artist's impression of globular star clusters surrounding the Milky Way.
Photos: Wonders of the universe
This is an artist's impression of globular star clusters surrounding the Milky Way.
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An artist's impression of life on a planet in orbit around a binary star system, visible as two suns in the sky.
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An artist's impression of life on a planet in orbit around a binary star system, visible as two suns in the sky.
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An artist's illustration of one of the most distant solar system objects yet observed, 2018 VG18 -- also known as "Farout." The pink hue suggests the presence of ice. We don't yet have an idea of what "FarFarOut" looks like.
Photos: Wonders of the universe
An artist's illustration of one of the most distant solar system objects yet observed, 2018 VG18 -- also known as "Farout." The pink hue suggests the presence of ice. We don't yet have an idea of what "FarFarOut" looks like.
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This is an artist's concept of the tiny moon Hippocamp that was discovered by the Hubble Space Telescope. Only 20 miles across, it may actually be a broken-off fragment from a much larger neighboring moon, Proteus, seen as a crescent in the background.
Photos: Wonders of the universe
This is an artist's concept of the tiny moon Hippocamp that was discovered by the Hubble Space Telescope. Only 20 miles across, it may actually be a broken-off fragment from a much larger neighboring moon, Proteus, seen as a crescent in the background.
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In this illustration, an asteroid (bottom left) breaks apart under the powerful gravity of LSPM J0207+3331, the oldest, coldest white dwarf known to be surrounded by a ring of dusty debris. Scientists think the system's infrared signal is best explained by two distinct rings composed of dust supplied by crumbling asteroids.
Photos: Wonders of the universe
In this illustration, an asteroid (bottom left) breaks apart under the powerful gravity of LSPM J0207+3331, the oldest, coldest white dwarf known to be surrounded by a ring of dusty debris. Scientists think the system's infrared signal is best explained by two distinct rings composed of dust supplied by crumbling asteroids.
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An artist's impression of the warped and twisted Milky Way disk. This happens when the rotational forces of the massive center of the galaxy tug on the outer disk.
Photos: Wonders of the universe
An artist's impression of the warped and twisted Milky Way disk. This happens when the rotational forces of the massive center of the galaxy tug on the outer disk.
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This 1.3-kilometer (0.8-mile)-radius Kuiper Belt Object discovered by researchers on the edge of the solar system is believed to be the step between balls of dust and ice and fully formed planets.
Photos: Wonders of the universe
This 1.3-kilometer (0.8-mile)-radius Kuiper Belt Object discovered by researchers on the edge of the solar system is believed to be the step between balls of dust and ice and fully formed planets.
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A selfie taken by NASA's Curiosity Mars rover on Vera Rubin Ridge before it moves to a new location.
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A selfie taken by NASA's Curiosity Mars rover on Vera Rubin Ridge before it moves to a new location.
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The Hubble Space Telescope found a dwarf galaxy hiding behind a big star cluster that's in our cosmic neighborhood. It's so old and pristine that researchers have dubbed it a "living fossil" from the early universe.
Photos: Wonders of the universe
The Hubble Space Telescope found a dwarf galaxy hiding behind a big star cluster that's in our cosmic neighborhood. It's so old and pristine that researchers have dubbed it a "living fossil" from the early universe.
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How did massive black holes form in the early universe? The rotating gaseous disk of this dark matter halo breaks apart into three clumps that collapse under their own gravity to form supermassive stars. Those stars will quickly collapse and form massive black holes.
Photos: Wonders of the universe
How did massive black holes form in the early universe? The rotating gaseous disk of this dark matter halo breaks apart into three clumps that collapse under their own gravity to form supermassive stars. Those stars will quickly collapse and form massive black holes.
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NASA's Spitzer Space Telescope captured this image of the Large Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy. Astrophysicists now believe it could collide with our galaxy in two billion years.
Photos: Wonders of the universe
NASA's Spitzer Space Telescope captured this image of the Large Magellanic Cloud, a satellite galaxy to our own Milky Way galaxy. Astrophysicists now believe it could collide with our galaxy in two billion years.
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A mysterious bright object in the sky, dubbed "The Cow," was captured in real time by telescopes around the world. Astronomers believe that it could be the birth of a black hole or neutron star, or a new class of object.
Photos: Wonders of the universe
A mysterious bright object in the sky, dubbed "The Cow," was captured in real time by telescopes around the world. Astronomers believe that it could be the birth of a black hole or neutron star, or a new class of object.
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An illustration depicts the detection of a repeating fast radio burst from a mysterious source 3 billion light-years from Earth.
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An illustration depicts the detection of a repeating fast radio burst from a mysterious source 3 billion light-years from Earth.
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Comet 46P/Wirtanen will pass within 7 million miles of Earth on December 16. It's ghostly green coma is the size of Jupiter, even though the comet itself is about three-quarters of a mile in diameter.
Photos: Wonders of the universe
Comet 46P/Wirtanen will pass within 7 million miles of Earth on December 16. It's ghostly green coma is the size of Jupiter, even though the comet itself is about three-quarters of a mile in diameter.
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This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on December 2 by the OSIRIS-REx spacecraft from a range of 15 miles.
Photos: Wonders of the universe
This mosaic image of asteroid Bennu is composed of 12 PolyCam images collected on December 2 by the OSIRIS-REx spacecraft from a range of 15 miles.
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This image of a globular cluster of stars by the Hubble Space Telescope is one of the most ancient collections of stars known. The cluster, called NGC 6752, is more than 10 billion years old.
Photos: Wonders of the universe
This image of a globular cluster of stars by the Hubble Space Telescope is one of the most ancient collections of stars known. The cluster, called NGC 6752, is more than 10 billion years old.
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An image of Apep captured with the VISIR camera on the European Southern Observatory's Very Large Telescope. This "pinwheel" star system is most likely doomed to end in a long-duration gamma-ray burst.
Photos: Wonders of the universe
An image of Apep captured with the VISIR camera on the European Southern Observatory's Very Large Telescope. This "pinwheel" star system is most likely doomed to end in a long-duration gamma-ray burst.
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An artist's impression of galaxy Abell 2597, showing the supermassive black hole expelling cold molecular gas like the pump of a giant intergalactic fountain.
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An artist's impression of galaxy Abell 2597, showing the supermassive black hole expelling cold molecular gas like the pump of a giant intergalactic fountain.
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An image of the Wild Duck Cluster, where every star is roughly 250 million years old.
Photos: Wonders of the universe
An image of the Wild Duck Cluster, where every star is roughly 250 million years old.
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These images reveal the final stage of a union between pairs of galactic nuclei in the messy cores of colliding galaxies.
Photos: Wonders of the universe
These images reveal the final stage of a union between pairs of galactic nuclei in the messy cores of colliding galaxies.
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A radio image of hydrogen gas in the Small Magellanic Cloud. Astronomers believe that the dwarf galaxy is slowly dying and will eventually be consumed by the Milky Way.
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A radio image of hydrogen gas in the Small Magellanic Cloud. Astronomers believe that the dwarf galaxy is slowly dying and will eventually be consumed by the Milky Way.
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Further evidence of a supermassive black hole at the center of the Milky Way galaxy has been found. This visualization uses data from simulations of orbital motions of gas swirling around about 30% of the speed of light on a circular orbit around the black hole.
Photos: Wonders of the universe
Further evidence of a supermassive black hole at the center of the Milky Way galaxy has been found. This visualization uses data from simulations of orbital motions of gas swirling around about 30% of the speed of light on a circular orbit around the black hole.
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Does this look like a bat to you? This giant shadow comes from a bright star reflecting against the dusty disk surrounding it.
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Does this look like a bat to you? This giant shadow comes from a bright star reflecting against the dusty disk surrounding it.
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Hey, Bennu! NASA's OSIRIS-REx mission, on its way to meet the primitive asteroid Bennu, is sending back images as it gets closer to its December 3 target.
Photos: Wonders of the universe
Hey, Bennu! NASA's OSIRIS-REx mission, on its way to meet the primitive asteroid Bennu, is sending back images as it gets closer to its December 3 target.
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These three panels reveal a supernova before, during and after it happened 920 million light-years from Earth(from left to right). The supernova, dubbed iPTF14gqr, is unusual because although the star was massive, its explosion was quick and faint. Researchers believe this is due to a companion star that siphoned away its mass.
Photos: Wonders of the universe
These three panels reveal a supernova before, during and after it happened 920 million light-years from Earth(from left to right). The supernova, dubbed iPTF14gqr, is unusual because although the star was massive, its explosion was quick and faint. Researchers believe this is due to a companion star that siphoned away its mass.
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This is an artist's illustration of what a Neptune-size moon would look like orbiting the gas giant exoplanet Kepler-1625b in a star system 8,000 light-years from Earth. It could be the first exomoon ever discovered.
Photos: Wonders of the universe
This is an artist's illustration of what a Neptune-size moon would look like orbiting the gas giant exoplanet Kepler-1625b in a star system 8,000 light-years from Earth. It could be the first exomoon ever discovered.
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An artist's illustration of Planet X, which could be shaping the orbits of smaller extremely distant outer solar system objects like 2015 TG387.
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An artist's illustration of Planet X, which could be shaping the orbits of smaller extremely distant outer solar system objects like 2015 TG387.
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This is an artist's concept of what SIMP J01365663+0933473 might look like. It has 12.7 times the mass of Jupiter but a magnetic field 200 times more powerful than Jupiter's. This object is 20 light-years from Earth. It's on the boundary line between being a planet or being a brown dwarf.
Photos: Wonders of the universe
This is an artist's concept of what SIMP J01365663+0933473 might look like. It has 12.7 times the mass of Jupiter but a magnetic field 200 times more powerful than Jupiter's. This object is 20 light-years from Earth. It's on the boundary line between being a planet or being a brown dwarf.
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The Andromeda galaxy cannibalized and shredded the once-large galaxy M32p, leaving behind this compact galaxy remnant known as M32. It is completely unique and contains a wealth of young stars.
Photos: Wonders of the universe
The Andromeda galaxy cannibalized and shredded the once-large galaxy M32p, leaving behind this compact galaxy remnant known as M32. It is completely unique and contains a wealth of young stars.
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Twelve new moons have been found around Jupiter. This graphic shows various groupings of the moons and their orbits, with the newly discovered ones shown in bold.
Photos: Wonders of the universe
Twelve new moons have been found around Jupiter. This graphic shows various groupings of the moons and their orbits, with the newly discovered ones shown in bold.
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Scientists and observatories around the world were able to trace a high-energy neutrino to a galaxy with a supermassive, rapidly spinning black hole at its center, known as a blazar. The galaxy sits to the left of Orion's shoulder in his constellation and is about 4 billion light-years from Earth.