Black Holes of the Universe
1. Here Comes the Warm Jets
Combining observations done with ESO’s Very Large Telescope and NASA’s Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. The black hole blows a huge bubble of hot gas, 1000 light-years
2. Radio Waves
This artist’s concept shows a galaxy with a supermassive black hole at its core. The black hole is shooting out jets of radio waves. New research led by theoretical astrophysicist David Garofalo of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., sug
3. Eat to the Beat
Artist’s schematic impression of the distortion of space-time by a supermassive black hole at the center of a galaxy. The black hole will swallow dark matter at a rate which depends on its mass and on the amount of dark matter around it.
4. Portrait of the Quasar as a Young Black Hole
Illustration of a young black hole, such as the two distant dust-free quasars spotted recently by the Spitzer Space Telescope.
5. Beware of the Blob
This illustration shows what one of the galaxies inside a blob might look like, with the spiral arms of the galaxy in yellow and white, and two-sided outflow powered by the supermassive black hole buried inside shown in bright yellow.
(Source: space.com)
Seeds of massive black holes found at center of the Milky Way
A research team has discovered masses thought to be “seeds” that form and grow massive black holes at the center of the Milky Way Galaxy, about 30,000 light-years from our solar system in the direction of Sagittarius.
Top 10 Strangest Things in Space
The universe is a weird place. Here’s a look at some of the strangest things in the cosmos.
1. Antimatter
Like Superman’s alter-ego, Bizzaro, the particles making up normal matter also have opposite versions of themselves. An electron has a negative charge, for example, but its antimatter equivalent, the positron, is positive. Matter and antimatter annihilate each other when they collide and their mass is converted into pure energy by Einstein’s equation E=mc2. Some futuristic spacecraft designs incorporate anti-matter engines.
2. Mini-Black Holes
If a radical new “braneworld” theory of gravity is correct, then scattered throughout our solar system are thousands of tiny black holes, each about the size of an atomic nucleus. Unlike their larger brethren, these mini-black holes are primordial leftovers from the Big Bang and affect space-time differently because of their close association with a fifth dimension.
3. Cosmic Microwave Background
Also known as the CMB, this radiation is a primordial leftover from the Big Bang that birthed the universe. It was first detected during the 1960s as a radio noise that seemed to emanate from everywhere in space. The CMB is regarded as one of the best pieces of evidence for the theoretical Big Bang. Recent precise measurements by the WMAP project place the CMB temperature at -455 degrees Fahrenheit (-270 Celsius).
4. Dark Matter
Scientists think it makes up the bulk of matter in the universe, but it can neither be seen nor detected directly using current technologies. Candidates range from light-weight neutrinos to invisible black holes. Some scientists question whether dark matter is even real, and suggest that the mysteries it was conjured to solve could be explained by a better understanding of gravity.
5. Exoplanets
Until about the early 1990s, the only known planets in the universe were the familiar ones in our solar system. Astronomers have since identified more than 500 extrasolar planets (as of November 2010). They range from gargantuan gas worlds whose masses are just shy of being stars to small, rocky ones orbiting dim, red dwarfs. Searches for a second Earth, however, are still ongoing. Astronomers generally believe that better technology is likely to eventually reveal worlds similar to our own.
6. Gravity Waves
Gravity waves are distortions in the fabric of space-time predicted by Albert Einstein’s theory of general relativity. The gravitational waves travel at the speed of light, but they are so weak that scientists expect to detect only those created during colossal cosmic events, such as black hole mergers like the one shown above. LIGO and LISA are two detectors designed to spot the elusive waves.
7. Galactic Cannibalism
Like life on Earth, galaxies can “eat” each other and evolve over time. The Milky Way’s neighbor, Andromeda, is currently dining on one of its satellites. More than a dozen star clusters are scattered throughout Andromeda, the cosmic remains of past meals. The image above is from a simulation of Andromeda and our galaxy colliding, an event that will take place in about 3 billion years.
8. Neutrinos
Neutrinos are electrically neutral, virtually mass-less elementary particles that can pass through miles of lead unhindered. Some are passing through your body as you read this. These “phantom” particles are produced in the inner fires of burning, healthy stars as well as in the supernova explosions of dying stars. Detectors are being embedded underground, beneath the sea, or into a large chunk of ice as part of IceCube, a neutrino-detecting project.
9. Quasars
These bright beacons shine to us from the edges of the visible universe and are reminders to scientists of our universe’s chaotic infancy. Quasars release more energy than hundreds of galaxies combined. The general consensus is that they aremonstrous black holes in the hearts of distant galaxies. This image is of quasar 3C 273, photographed in 1979.
10. Vacuum Energy
Quantum physics tells us that contrary to appearances, empty space is a bubbling brew of “virtual” subatomic particles that are constantly being created and destroyed. The fleeting particles endow every cubic centimeter of space with a certain energy that, according to general relativity, produces an anti-gravitational force that pushes space apart. Nobody knows what’s really causing the accelerated expansion of the universe, however.
(Source: space.com)
6 Weird Facts About Gravity
Gravity: You don’t know what you’ve got ‘til it’s gone
Here on Earth, we take gravity so for granted that it took an apple falling from a tree to trigger Isaac Newton’s theory of gravitation. But gravity, which draws objects together in proportion to their mass, is about much more than fallen fruit. Read on for some of the strangest facts about this universal force.
1. It’s all in your head
Gravity may be pretty consistent on Earth, but our perception of it isn’t. According to research published in April 2011 in the journal PLoS ONE, people are better at judging how objects fall when they’re sitting upright versus lying on their sides.
The finding means that our perception of gravity may be less based on visual cues of gravity’s real direction and more rooted in the orientation of the body. The findings may lead to new strategies to help astronauts deal with microgravity in space.
2. Coming down to Earth is tough
Speaking of astronauts, their experience has shown that a switch to weightlessness and back can be tough on the body. In the absence of gravity, muscles atrophy and bones likewise lose bone mass. According to NASA, astronauts can lose 1 percent of their bone mass per month in space.
When astronauts come back to Earth, their bodies and minds need time to recover. Blood pressure, which has equalized throughout the body in space, has to return to an Earthly pattern in which the heart must work hard to keep the brain nourished with blood. Occasionally, astronauts struggle with that adjustment. In 2006, astronaut Heidemarie Stefanyshyn-Piper collapsed at a welcome-home ceremony the day after returning from a Space Shuttle mission to the International Space Station.
The mental readjustment can be just as tricky. In 1973, Skylab 2 astronaut Jack Lousma told Time magazine that he’d accidentally smashed a bottle of aftershave in his first days back from a month-long sojourn in space. He’d let go of the bottle in mid-air, forgetting that it would crash to the ground rather than just float there
3. For weight loss, try Pluto
Pluto may no longer be a planet, but it’s still a good bet for lightening up. A 150-pound (68 kilogram) person would weigh no more than 10 pounds (4.5 kg) on the dwarf planet. The planet with the most crushing gravity, on the other hand, is Jupiter, where the same person would weigh more than 354 pounds (160.5 kg).
The planet humans are most likely to visit, Mars, would also leave explorers feeling light-footed. Mars’ gravitational pull is only 38 percent that of Earth’s, meaning a 150-pound person would feel like they weigh about 57 pounds (26 kg).
4. Gravity is lumpy
Even on Earth, gravity isn’t entirely even. Because the globe isn’t a perfect sphere, its mass is distributed unevenly. And uneven mass means slightly uneven gravity.
One mysterious gravitational anomaly is in the Hudson Bay of Canada (shown above). This area has lower gravity than other regions, and a 2007 study finds that now-melted glaciers are to blame.
The ice that once cloaked the area during the last ice age has long since melted, but the Earth hasn’t entirely snapped back from the burden. Since gravity over an area is proportional to the mass atop that region, and the glacier’s imprint pushed aside some of the Earth’s mass, gravity is a bit less strong in the ice sheet’s imprint. The slight deformation of the crust explains 25 percent to 45 percent of the unusually low gravity; the rest may be explained by a downward drag caused the motion of magma in Earth’s mantle (the layer just beneath the crust), researchers reported in the journal Science.
5. Without gravity, some bugs get tougher
Bad news for space cadets: Some bacteria become nastier in space. A 2007 study published in the journal Proceedings of the National Academy of Sciences found that salmonella, the bacteria that commonly causes food poisoning, becomes three times more virulent in microgravity. Something about the lack of gravity changed the activity of at least 167 salmonella genes and 73 of its proteins. Mice fed the gravity-free salmonella got sick faster after consuming less of the bacteria.
In other words, Michael Crichton’s “The Andromeda Strain” had it wrong: The danger of infection in space may not come from space bugs. It’s more likely our own bugs grown stronger would strike us.
6. Black holes at the center of galaxies
Named because nothing, not even light, can escape their gravitational clutches, black holes are some of the most destructive objects in the universe. At the center of our galaxy is a massive black hole with the mass of 3 million suns. Scarier thought? It might be “just resting,” according Kyoto University scientist Tatsuya Inui.
The black hole isn’t really a danger to us Earthlings — it’s both far away and it’s remarkably calm. But sometimes it does put on a show: Inui and colleagues reported in 2008 that the black hole sent out a flare of energy 300 years ago. Another study, released in 2007, found that several thousand years ago, a galactic hiccup sent a small amount of matter the size of Mercury falling into the black hole, leading to another outburst.
The black hole, named Sagittarius A*, is dim compared with other black holes.
“This faintness implies that stars and gas rarely get close enough to the black hole to be in any danger,” Frederick Baganoff, a researcher at the Massachusetts Institute of Technology who was involved with the 2007 study, told LiveScience’s sister site SPACE.com. “The huge appetite is there, but it’s not being satisfied.”
Black Holes
As two black holes spiral into each other, they produce gravity waves that contain energy 100 billion trillion times the power of our sun.
