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Black Ops and UFOs: The Hidden Truth Revealed
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By NASA
This article is for students grades 5-8
A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star’s life. Some black holes are a result of dying stars.
Because no light can escape, black holes are invisible. However, space telescopes with special instruments can help find black holes. They can observe the behavior of material and stars that are very close to black holes.
How Big Are Black Holes?
Black holes can come in a range of sizes, but there are three main types of black holes. The black hole’s mass and size determine what kind it is.
The smallest ones are known as primordial black holes. Scientists believe this type of black hole is as small as a single atom but with the mass of a large mountain.
The most common type of medium-sized black holes is called “stellar.” The mass of a stellar black hole can be up to 20 times greater than the mass of the sun and can fit inside a ball with a diameter of about 10 miles. Dozens of stellar mass black holes may exist within the Milky Way galaxy.
The largest black holes are called “supermassive.” These black holes have masses greater than 1 million suns combined and would fit inside a ball with a diameter about the size of the solar system. Scientific evidence suggests that every large galaxy contains a supermassive black hole at its center. The supermassive black hole at the center of the Milky Way galaxy is called Sagittarius A. It has a mass equal to about 4 million suns and would fit inside a ball with a diameter about the size of the sun.
How Do Black Holes Form?
Primordial black holes are thought to have formed in the early universe, soon after the big bang.
Stellar black holes form when the center of a very massive star collapses in upon itself. This collapse also causes a supernova, or an exploding star, that blasts part of the star into space.
Scientists think supermassive black holes formed at the same time as the galaxy they are in. The size of the supermassive black hole is related to the size and mass of the galaxy it is in.
If Black Holes Are “Black,” How Do Scientists Know They Are There?
A black hole can not be seen because of the strong gravity that is pulling all of the light into the black hole’s center. However, scientists can see the effects of its strong gravity on the stars and gases around it. If a star is orbiting a certain point in space, scientists can study the star’s motion to find out if it is orbiting a black hole.
When a black hole and a star are orbiting close together, high-energy light is produced. Scientific instruments can see this high-energy light.
A black hole’s gravity can sometimes be strong enough to pull off the outer gases of the star and grow a disk around itself called the accretion disk. As gas from the accretion disk spirals into the black hole, the gas heats to very high temperatures and releases X-ray light in all directions. NASA telescopes measure the X-ray light. Astronomers use this information to learn more about the properties of a black hole.
Could a Black Hole Destroy Earth?
Black holes do not wander around the universe, randomly swallowing worlds. They follow the laws of gravity just like other objects in space. The orbit of a black hole would have to be very close to the solar system to affect Earth, which is not likely.
If a black hole with the same mass as the sun were to replace the sun, Earth would not fall in. The black hole with the same mass as the sun would keep the same gravity as the sun. The planets would still orbit the black hole as they orbit the sun now.
Will the Sun Ever Turn Into a Black Hole?
The sun does not have enough mass to collapse into a black hole. In billions of years, when the sun is at the end of its life, it will become a red giant star. Then, when it has used the last of its fuel, it will throw off its outer layers and turn into a glowing ring of gas called a planetary nebula. Finally, all that will be left of the sun is a cooling white dwarf star.
How Is NASA Studying Black Holes?
NASA is learning about black holes using spacecraft like the Chandra X-ray Observatory, the Swift satellite and the Fermi Gamma-ray Space Telescope. Fermi launched in 2008 and is observing gamma rays – the most energetic form of light – in search of supermassive black holes and other astronomical phenomena. Spacecraft like these help scientists answer questions about the origin, evolution and destiny of the universe.
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Words to Know
mass: the measurement for the amount of matter in an object
red giant star: a star that is larger than the sun and red
because it has a lower temperature
white dwarf star: a small star, about the size of Earth;
one of the last stages of a star’s life
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Read What Is a Black Hole? (Grades K-4)
Explore More for Students Grades 5-8 View the full article
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By NASA
This article is for students grades K-4.
A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.
Because no light can get out, people can’t see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.
How Big Are Black Holes?
Black holes can be big or small. Scientists think the smallest black holes are as small as just one atom. These black holes are very tiny but have the mass of a large mountain. Mass is the amount of matter, or “stuff,” in an object.
Another kind of black hole is called “stellar.” Its mass can be up to 20 times more than the mass of the sun. There may be many, many stellar mass black holes in Earth’s galaxy. Earth’s galaxy is called the Milky Way.
The largest black holes are called “supermassive.” These black holes have masses that are more than 1 million suns together. Scientists have found proof that every large galaxy contains a supermassive black hole at its center.
The supermassive black hole at the center of the Milky Way galaxy is called Sagittarius A. It has a mass equal to about 4 million suns and would fit inside a very large ball that could hold a few million Earths.
How Do Black Holes Form?
Scientists think the smallest black holes formed when the universe began.
Stellar black holes are made when the center of a very big star falls in upon itself, or collapses. When this happens, it causes a supernova. A supernova is an exploding star that blasts part of the star into space.
Scientists think supermassive black holes were made at the same time as the galaxy they are in.
If Black Holes Are “Black,” How Do Scientists Know They Are There?
A black hole can not be seen because strong gravity pulls all of the light into the middle of the black hole. But scientists can see how the strong gravity affects the stars and gas around the black hole. Scientists can study stars to find out if they are flying around, or orbiting, a black hole.
When a black hole and a star are close together, high-energy light is made. This kind of light can not be seen with human eyes. Scientists use satellites and telescopes in space to see the high-energy light.
Could a Black Hole Destroy Earth?
Even if a black hole the same mass as the sun were to take the place of the sun, Earth still would not fall in. The black hole would have the same gravity as the sun. Earth and the other planets would orbit the black hole as they orbit the sun now.
Black holes do not go around in space eating stars, moons and planets. Earth will not fall into a black hole because no black hole is close enough to the solar system for Earth to do that.
The sun will never turn into a black hole. The sun is not a big enough star to make a black hole.
How Is NASA Studying Black Holes?
NASA is using satellites and telescopes that are traveling in space to learn more about black holes. These spacecraft help scientists answer questions about the universe.
More About Black Holes
Space Place in a Snap: What Is a Black Hole?
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Read What Is a Black Hole? (Grades 5-8)
Explore More For Students K-4 View the full article
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By NASA
Astronomers have discovered the most distant black hole yet seen in X-rays, using NASA telescopes. The black hole is at an early stage of growth that had never been witnessed before, where its mass is similar to that of its host galaxy.
This result may explain how some of the first supermassive black holes in the universe formed.
By combining data from NASA’s Chandra X-ray Observatory and NASA’s James Webb Space Telescope, a team of researchers was able to find the telltale signature of a growing black hole just 470 million years after the big bang.
This image contains the most distant black hole ever detected in X-rays, a result that may explain how some of the first supermassive black holes in the universe formed. As we report in our press release, this discovery was made using X-rays from NASA’s Chandra X-ray Observatory (purple) and infrared data from NASA’s James Webb Space Telescope (red, green, blue).X-ray: NASA/CXC/SAO/Ákos Bogdán; Infrared: NASA/ESA/CSA/STScI; Image Processing: NASA/CXC/SAO/L. Frattare & K. Arcand See full image
“We needed Webb to find this remarkably distant galaxy and Chandra to find its supermassive black hole,” said Akos Bogdan of the Center for Astrophysics | Harvard & Smithsonian (CfA) who leads a new paper in the journal Nature Astronomy describing these results. “We also took advantage of a cosmic magnifying glass that boosted the amount of light we detected.” This magnifying effect is known as gravitational lensing.
Bogdan and his team found the black hole in a galaxy named UHZ1 in the direction of the galaxy cluster Abell 2744, located 3.5 billion light-years from Earth. Webb data, however, has revealed the galaxy is much more distant than the cluster, at 13.2 billion light-years from Earth, when the universe was only 3% of its current age.
Then over two weeks of observations with Chandra showed the presence of intense, superheated, X-ray emitting gas in this galaxy – a trademark for a growing supermassive black hole. The light from the galaxy and the X-rays from gas around its supermassive black hole are magnified by about a factor of four by intervening matter in Abell 2744 (due to gravitational lensing), enhancing the infrared signal detected by Webb and allowing Chandra to detect the faint X-ray source.
This discovery is important for understanding how some supermassive black holes can reach colossal masses soon after the big bang. Do they form directly from the collapse of massive clouds of gas, creating black holes weighing between about 10,000 and 100,000 Suns? Or do they come from explosions of the first stars that create black holes weighing only between about 10 and 100 Suns?
“There are physical limits on how quickly black holes can grow once they’ve formed, but ones that are born more massive have a head start. It’s like planting a sapling, which takes less time to grow into a full-size tree than if you started with only a seed”, said Andy Goulding of Princeton University. Goulding is a co-author of the Nature Astronomy paper and lead author of a new paper in The Astrophysical Journal Letters that reports the galaxy’s distance and mass using a spectrum from Webb.
Bogdan’s team has found strong evidence that the newly discovered black hole was born massive. Its mass is estimated to fall between 10 and 100 million Suns, based on the brightness and energy of the X-rays. This mass range is similar to that of all the stars in the galaxy where it lives, which is in stark contrast to black holes in the centers of galaxies in the nearby universe that usually contain only about a tenth of a percent of the mass of their host galaxy’s stars.
The large mass of the black hole at a young age, plus the amount of X-rays it produces and the brightness of the galaxy detected by Webb, all agree with theoretical predictions in 2017 by co-author Priyamvada Natarajan of Yale University for an “Outsize Black Hole” that directly formed from the collapse of a huge cloud of gas.
“We think that this is the first detection of an ‘Outsize Black Hole’ and the best evidence yet obtained that some black holes form from massive clouds of gas,” said Natarajan. “For the first time we are seeing a brief stage where a supermassive black hole weighs about as much as the stars in its galaxy, before it falls behind.”
The researchers plan to use this and other results pouring in from Webb and those combining data from other telescopes to fill out a larger picture of the early universe.
“Results like this show why NASA has a portfolio of elite telescopes,” said Mark Clampin, director of the Astrophysics Division at NASA Headquarters. “Each has their own superpowers, so to speak, and they can accomplish amazing things when they join forces.”
NASA’s Hubble Space Telescope previously showed that light from distant galaxies is highly magnified by matter in the intervening galaxy cluster, providing part of the motivation for the Webb and Chandra observations described here.
The paper describing the results by Bogdan’s team appears in Nature Astronomy, and a preprint is available online.
The Webb data used in both papers is part of a survey called the Ultradeep Nirspec and nirCam ObserVations before the Epoch of Reionization (UNCOVER). The paper led by UNCOVER team member Andy Goulding appears in the Astrophysical Journal Letters, and a preprint is available online. The co-authors include other UNCOVER team members, plus Bogdan and Natarajan. A detailed interpretation paper that compares observed properties of UHZ1 with theoretical models for Outsize Black Hole Galaxies is forthcoming.
NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Read more from NASA’s Chandra X-ray Observatory.
For more Chandra images, multimedia and related materials, visit:
https://www.nasa.gov/mission/chandra-x-ray-observatory/
Megan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
Jonathan Deal
Marshall Space Flight Center
Huntsville, Ala.
256-544-0034
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By NASA
Artist’s concept showing two of the seven planets discovered orbiting a Sun-like star. The system, called Kepler-385, was identified using data from NASA’s Kepler mission.NASA/Daniel Rutter A system of seven sweltering planets has been revealed by continued study of data from NASA’s retired Kepler space telescope: Each one is bathed in more radiant heat from their host star per area than any planet in our solar system. Also unlike any of our immediate neighbors, all seven planets in this system, named Kepler-385, are larger than Earth but smaller than Neptune. It is one of only a few planetary systems known to contain more than six verified planets or planet candidates. The Kepler-385 system is among the highlights of a new Kepler catalog that contains almost 4,400 planet candidates, including more than 700 multi-planet systems.
“We’ve assembled the most accurate list of Kepler planet candidates and their properties to date,” said Jack Lissauer, a research scientist at NASA’s Ames Research Center in California’s Silicon Valley and lead author on the paper presenting the new catalog. “NASA’s Kepler mission has discovered the majority of known exoplanets, and this new catalog will enable astronomers to learn more about their characteristics.”
At the center of the Kepler-385 system is a Sun-like star about 10% larger and 5% hotter than the Sun. The two inner planets, both slightly larger than Earth, are probably rocky and may have thin atmospheres. The other five planets are larger – each with a radius about twice the size of Earth’s – and expected to be enshrouded in thick atmospheres.
Artist’s concept of Kepler-385, the seven-planet system revealed in a new catalog of planet candidates discovered by NASA’s Kepler space telescope.NASA/Daniel Rutter The ability to describe the properties of the Kepler-385 system in such detail is testament to the quality of this latest catalog of exoplanets. While the Kepler mission’s final catalogs focused on producing lists optimized to measure how common planets are around other stars, this study focuses on producing a comprehensive list that provides accurate information about each of the systems, making discoveries like Kepler-385 possible.
The new catalog uses improved measurements of stellar properties and calculates more accurately the path of each transiting planet across its host star. This combination illustrates that when a star hosts several transiting planets, they typically have more circular orbits than when a star hosts only one or two.
Kepler’s primary observations ceased in 2013 and were followed by the telescope’s extended mission, called K2, which continued until 2018. The data Kepler collected continues to reveal new discoveries about our galaxy. After the mission already showed us there are more planets than stars, this new study paints a more detailed picture of what each of those planets and their home systems look like, giving us a better view of the many worlds beyond our solar system.
The research article, “Updated Catalog of Kepler Planet Candidates: Focus on Accuracy and Orbital Periods” is forthcoming in The Journal of Planetary Science.
Learn more:
Listen to a sonification of the orbit data of the seven planets in the Kepler-385 system: https://www.youtube.com/watch?v=2BCiOTJjcQQ
For news media:
Members of the news media interested in covering this topic should reach out to the NASA Ames newsroom.
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By NASA
2 min read
New Patterns in Mars’s Clouds Revealed by Volunteers
Volunteers found that clouds in Mars’s atmosphere cluster at certain latitudes and altitudes. White patches in this pair of plots shows where Cloudspotting participants spotted the most clouds (or “arch peaks” in the project lingo). Red labels highlight a few interesting regions: 1) where high-altitude Carbon Dioxide-ice clouds form; 2) water-ice clouds that show a different pattern between day and night; and 3) clouds that form in a cold region over the poles. Credit: Adapted from Slipski et al. (in press), https://doi.org/10.1016/j.icarus.2023.115777. The first journal article about clouds identified by participants of the Cloudspotting on Mars project has been accepted for publication and is now available online! The article, “The Cloudspotting on Mars citizen science project: Seasonal and spatial cloud distributions observed by the Mars Climate Sounder” will appear in a special issue of Icarus titled “MRO: 16 Years at Mars”. MRO is the Mars Reconnaissance Orbiter, the Mars Climate Sounder is an instrument on MRO.
The paper shows several cloud maps, illustrating times and regions where many clouds were identified. The maps reveal several key cloud populations identified in data from the volunteers. The cloud populations include high-altitude CO2-ice clouds, clouds that form near the poles, and dusty-season water-ice clouds. The structure of the clouds follows the pattern of “thermal tides” in the atmosphere, which are global-scale oscillations in temperature. Where temperatures are lower than average, clouds are more common.
The paper also explains the motivation for the project and describes its setup on Zooniverse. It digs into the details of how cloud identifications made by participants were turned into a cloud catalog using machine learning. “Thank you to all the Cloudspotting on Mars participants for driving this research forward!” said project PI Dr. Marek Slipski, a research scientist at NASA’s Jet propulsion Laboratory.
There’s plenty more to study in this dataset and there are more images online to analyze: the second Mars Year of data is only about 50% done. The data from the second Mars year will help reveal how changing dust conditions affect cloud formation. If you’d like to join the search for clouds in the Martian atmosphere, head to https://www.zooniverse.org/projects/marek-slipski/cloudspotting-on-mars.
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