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Galaxies
Galaxies are large systems of stars and interstellar matter, and they contain billions of stars. Our own galaxy, the Milky Way, has 200 to 400 billion stars, and there are over one billion known galaxies. Questions that have to do with galaxies in general and specific galaxies are perfect for this category!
2,392 Questions
The bright center of a distant galaxy is likely a supermassive black hole. The friction and collision of material spiraling around the black hole generates high temperatures and intense light emissions, making it appear bright from afar. This process is known as "accretion" and is a key feature of active galactic nuclei.
The longest day on earth is called the?
The longest day on earth is called the summer solstice. It occurs around June 21st in the Northern Hemisphere and around December 21st in the Southern Hemisphere. On this day, the North Pole is tilted closest to the sun, resulting in the longest period of daylight of the year.
Do partial lunar eclipse occur more often than total eclipse?
Total solar eclipses are much less frequent because it is much more likely that part of a planet/moon/satellite gets partly in our way of the sun than a planet/moon/satellite gets 100% in our way.
Why is there radiation in galaxies?
This is a difficult question to answer, like many things in science. We know they exist, but we wonder why.
Gravity exists, we roughly know how it works and its effects, why it exists? It just does. It happened to be a part of the laws of physics put into motion once the universe formed.
Radiation as it is commonly thought of, for example alpha radiation, is given off by the decay of certain elements. Radon gas is radioactive, thus it decays slowly to a more stable state and in doing so it releases charged particles - alpha.
We know things happen, we know how they happen and can predict when.
What we really will never know (probably) is why.
The spectra of most galaxies show redshifts this means that their spectral lines are what?
The spectral lines of galaxies are redshifted, indicating that they are moving away from Earth. This redshift is typically a result of the expansion of the universe, causing galaxies to move further apart.
What is the closest galaxy to milky way?
It is the Sagittarius Dwarf Galaxy. The Canis Major Dwarf Galaxy is the second closest to the milky way.
Ed Conrad is a layman who in the early 1980s discovered some rocks in a coal field which he believes are human skulls which date back 280 million years or so, 200 million years before modern science claims that man evolved. These rocks have been examined by scientists, including those at the Smithsonian Institute, who have reported that the rocks are just rocks and not of human origin, but Conrad persists in believing there is a mass conspiracy among anthropologists and paleontologists to keep it secret as to when man actually first appeared on Earth. He posts regularly in several Usenet news groups devoted to the origins of man, frequently changing his username to get around the filters that people set to avoid his posts.
A globular cluster is a dense group of old stars within a galaxy that have formed a gravity bound spherical shape. They are composed of hundreds of thousands of stars that orbit the center of the galaxy together as a unit. We we don't know a lot about them. There are between one and two hundred globular clusters in the Milky Way, and thousands in very large galaxies, all hanging out around the galactic core.
Wikipedia has more information, and a link posted below will take the curious reader over there. Why not drop by and look at the picture of Messier 80 that was put up by our friends?
The Andromeda Galaxy is the nearest spiral galaxy to our Milky Way, located about 2.5 million light-years away. It is home to about a trillion stars and has a diameter of approximately 220,000 light-years. Andromeda is on a collision course with the Milky Way and is expected to merge with our galaxy in about 4 billion years.
What is the chemical composition of most stars?
Most stars are composed primarily of hydrogen and helium, with hydrogen making up about 75% of their mass and helium about 25%. The remaining elements in stars are present in trace amounts, including carbon, oxygen, nitrogen, and other heavier elements.
What are the names of the 2 new planets?
They are categorized as "dwarf planets" now, leaving only 8 regular planets in our solar system. The names of all the dwarf planets are:
Ceres
Pluto
Haumea
Makemake
Eris
The nearest large Galaxy is the Andromeda Galaxy or M31 (also Great Andromeda Nebula in old texts)
It is a spiral galaxy, located about 2.5 million years from us.
Unlike most galaxies, the Andromeda Galaxy is getting nearer to us and will eventually in a few billion years time "merge" with the Milky Way.
See related link for more information
When a star explodes what is it called?
When a blue star blows up t is called a supernova, which eventually leads into the formation of a black hole. Although a regular star, say our sun, doesn't blow up, it turns into a huge super giant, it grows 5X its normal size and it will either gulp earth up, or burn us to death, but don't worry, that won't happen for a couple billion years, but not so good for your Great Great Great Great Great Great Great Great Great [could go forever] grand children :D
What is the milkyway made up of?
milky way is made up of dust and matter. these are the base and when combine, they form stars, planets. matter is antimatter and black matter, which is hence the createrand the destroyer or the god matter
How many seconds does it take sunlight to reach earth?
With the average distance or "mean" distance from the Earth to the sun set at approximately 93,000,000 miles, and the speed of light at about 186,000 miles per second; the time in seconds it takes sunlight to reach the earth is appoximately "500 seconds". Most people refer to the time in minutes which would be about 8.333333 minutes.
When did the milky way galaxy form?
well in my search i came up on these 2 explainations:
1) The Milky Way is a translation of the Latin Via Lactea, which in turn is derived from Greek (Galaxias) sometimes referred to simply as "the Galaxy".
2) "The Ganga of the sky", is the ancient Hindu name for the galaxy as viewed from the Earth. this was called "Akash Ganga ", it is the Hindi name for Milky way.
hope that helps....
Which galaxy does our solar system belong to?
Not "galaxies", just one galaxy. Our galaxy is called the Milky Way.
Is a meteor going to hit earth in 2012?
Several thousands of meteors hit the Earth each day. Most of them are the size of a grain of rice or smaller. A few each day may be the size of a baseball or occasionally the size of a basketball.
Once a week or so, the Earth is hit by a rock the size of a car, and once every few months, we get hit by something the size of a house. A couple of months ago, a meteor the size of a house exploded over central Indonesia; it scared a lot of folks, but apparently did no damage.
The VAST majority of these burn up completely in the atmosphere, surviving as nothing but dust. A few do make it to the Earth, often in small (fist-sized) chunks. Very few do any damage. Only a few people are known to have been hit by a meteorite; there was a boy in Germany last year who was struck in the hand by a meteorite the size of a pea. And how would you have liked to explain to YOUR insurance company that your new car was destroyed when a meteorite punched down through the roof and buried itself in your driveway? It happened!
Every few hundred years, bigger things hit the Earth, and some do a lot of damage. In 1908, a meteor or small comet exploded high in the atmosphere near a place called Tunguska, Siberia, causing an explosion the size of a nuclear bomb. 5000 years ago, a meteor struck in the Indian Ocean causing a tsunami, which may be the source of the "Great Flood" legends in Gilgamesh and Noah's Ark. 14000 years ago, something hit northern Canada causing the "Younger Dryas" mini-ice age.
It's called a "meteoroid" when it is out in space. When it enters the Earth's atmosphere and is heated to incandescence, the bright streak of light is called a "meteor".
If the object survives the fiery passage through the atmosphere and hits the ground, it is called a "meteorite".
We are not currently aware of any specific meteoroids or asteroids that are on a path to hit the Earth.
"NGC" in Xilinx refers to the Xilinx-specific netlist format used for implementing custom logic in Xilinx FPGAs. NGC files contain the design information and constraints necessary for synthesis and implementation in Xilinx tools. These files are generated from HDL-based designs during the synthesis process.
How many stars make up a globular cluster?
Globular clusters can contain anywhere from hundreds of thousands to millions of stars. The exact number varies depending on the cluster.
Spiral galaxies form from the collapse of a protogalactic cloud. Spiral galaxies consist of three components: a rotating disk, a bulge and a halo. Spiral galaxies, like the Milky Way, owe their shape to stars inside the protogalaxy developing at different intervals. The gas between forming stars continues to be compressed, and the resulting gravitational differences manhandle the protogalaxy's stars, dust and gas. When the protogalactic cloud collapses, the stars in the bulge and halo form first. These stars have rather random orbits around the galactic center. The galactic center probably contains a supermassive black hole, which likely exerts some gravitational influence on the formation of a spiral galaxy.
The remainder of the cloud forms a disk due to the conservation of angular momentum (the same effect as the spinning up of the dancer when she pulls her arms inside). This motion forces everything into a rotating disk, and additional differences in gravity build the spiral arms. Oppositely, when a protogalaxy's stars develop at the same time, you have an elliptical galaxy on your hands. The stars in the disk form later and thus the disk population of stars are younger than those in the bulge and the halo. Further, the stars in the disk rotate around the center of the galaxy in a collective, well defined way unlike the stars in the bulge and halo.
Is solar system bigger than a Star?
A solar system consists of a star and other objects orbiting the star, so obviously the solar system is larger. Some very large stars could be bigger than the solar system of another small star.
Is there another place in the universe like the earth?
It's got the same climate as Earth, plus water and gravity. A newly discovered planet is the most stunning evidence that life - just like us - might be out there. Above a calm, dark ocean, a huge, bloated red sun rises in the sky - a full ten times the size of our Sun as seen from Earth. Small waves lap at a sandy shore and on the beach, something stirs...
More....
* Watch an animation of the new planet (Windows) * Watch an animation of the new planet (Real Player)
This is the scene - or may be the scene - on what is possibly the most extraordinary world to have been discovered by astronomers: the first truly Earth-like planet to have been found outside our Solar System. The discovery was announced today by a team of European astronomers, using a telescope in La Silla in the Chilean Andes. If forced bookies to slash odds on the existence of alien beings. The Earth-like planet that could be covered in oceans and may support life is 20.5 light years away, and has the right temperature to allow liquid water on its surface.
This remarkable discovery appears to confirm the suspicions of most astronomers that the universe is swarming with Earth-like worlds. We don't yet know much about this planet, but scientists believe that it may be the best candidate so far for supporting extraterrestrial life. The new planet, which orbits a small, red star called Gliese 581, is about one-and-a-half times the diameter of the Earth. It probably has a substantial atmosphere and may be covered with large amounts of water - necessary for life to evolve - and, most importantly, temperatures are very similar to those on our world.
It is the first exoplanet (a planet orbiting a star other than our own Sun) that is anything like our Earth. Of the 220 or so exoplanets found to date, most have either been too big, made of gas rather than solid material, far too hot, or far too cold for life to survive. "On the treasure map of the Universe, one would be tempted to mark this planet with an X," says Xavier Delfosse, one of the scientists who discovered the planet. "Because of its temperature and relative proximity, this planet will most probably be a very important target of the future space missions dedicated to the search for extraterrestrial life." Gliese 581 is among the closest stars to us, just 20.5 light years away (about 120 trillion miles) in the constellation Libra. It is so dim it can be seen only with a good telescope. Because all planets are relatively so small and the light they give off so faint compared to their sun, finding exoplanets is extremely difficult unless they are huge. Those that have so far been detected have mostly been massive, Jupiter-like balls of gas that almost certainly cannot be home to life. This new planet - known for the time being as Gliese 581c - is a midget in comparison, being about 12,000 miles across (Earth is a little under 8,000 pole-to-pole). It has a mass five times that of Earth, probably made of the same sort of rock as makes up our world and with enough gravity to hold a substantial atmosphere. Astrobiologists - scientists who study the possibility of alien life - refer to a climate known as the Goldilocks Zone, where it is not so cold that water freezes and not so hot that it boils, but where it can lie on the planet's surface as a liquid. In our solar system, only one planet - Earth -lies in the Goldilocks Zone. Venus is far too hot and Mars is just too cold. This new planet lies bang in the middle of the zone, with average surface temperatures estimated to be between zero and 40c (32-102f). Lakes, rivers and even oceans are possible. It is not clear what this planet is made of. If it is rock, like the Earth, then its surface may be land, or a combination of land and ocean. Another possibility is that Gliese 581c was formed mostly from ice far from the star (ice is a very common substance in the Universe), and moved to the close orbit it inhabits today. In which case its entire surface will have melted to form a giant, planet-wide ocean with no land, save perhaps a few rocky islands or icebergs. The surface gravity is probably around twice that of the Earth and the atmosphere could be similar to ours. Although the new planet is in itself very Earth-like, its solar system is about as alien as could be imagined. The star at the centre - Gliese 581 - is small and dim, only about a third the size of our Sun and about 50 times cooler. The two other planets are huge, Neptune-sized worlds called Gliese 581b and d (there is no "a", to avoid confusion with the star itself). The Earth-like planet orbits its sun at a distance of only six million miles or so (our Sun is 93 million miles away), travelling so fast that its "year" only lasts 13 of our days. The parent star would dominate the view from the surface - a huge red ball of fire that must be a spectacular sight. It is difficult to speculate what - if any - life there is on the planet. If there is life there it would have to cope with the higher gravity and solar radiation from its sun. Just because Gliese 581c is habitable does not mean that it is inhabited, but we do know its sun is an ancient star - in fact, it is one of the oldest stars in the galaxy, and extremely stable. If there is life, it has had many billions of years to evolve. This makes this planet a prime target in the search for life. According to Seth Shostak, of the Search for Extraterrestrial Intelligence Institute in California, the Gliese system is now a prime target for a radio search. 'We had actually looked at this system before but only for a few minutes. We heard nothing, but now we must look again.' By 2020 at least one space telescope should be in orbit, with the capability of detecting signs of life on planets orbiting nearby stars. If oxygen or methane (tell-tale biological gases) are found in Gliese 581c's atmosphere, this would be good circumstantial evidence for life. Dr Malcolm Fridlund, a European Space Agency scientist, said the discovery of Gliese 581c was "an important step" on the road to finding life. "If this is a rocky planet, it's very likely it will have liquid water on its surface, which means there may also be life." The real importance is not so much the discovery of this planet itself, but the fact that it shows that Earth-like planets are probably extremely common in the Universe. There are 200 billion stars in our galaxy alone and many astronomers believe most of these stars have planets. The fact that almost as soon as we have built a telescope capable of detecting small, earth-like worlds, one turns up right on our cosmic doorstep, shows that statistically, there are probably billions of earths out there. As Seth Shostak says: "We've never found one close to being like the Earth until now. We are finding that Earth is not such an unusual puppy in the litter of planets." But are these alien Earths home to life? No one knows. We don't understand how life began on our world, let alone how it could arise anywhere else. There may be an awful lot of bugs and bacteria out there, and only a few worlds with what we would recognise as plants and animals. Or, of course, there may be nothing. The Search for Extraterrestrial Intelligence Institute uses radio telescopes to try to pick up messages sent by alien civilisations. Interestingly, Gliese 581c is so close to the Earth that if its putative inhabitants only had our level of technology, they could - just about - pick up some of our radio signals, such as the most powerful military transmitters. Quite what would happen if we for our part did receive a signal is unclear. "There is a protocol, buried away in the United Nations," says Dr Shostak. "The President would be told first, after the signal was confirmed by other observatories. But we couldn't keep such a discovery secret." It may be some time before we detect any such signals, but it is just possible that today we are closer than ever to finding life in the stars. William Hill said it had shortened the odds on proving the existence of extraterrestrial intelligence from 1,000-1 to 100-1. Spokesman Graham Sharpe said: "We would face a possible eight-figure payout if it were to be confirmed that intelligent life of extra-terrestrial origin exists. We felt we had to react to the news that an earth-like planet which could support intelligent life had been discovered - after all, we don't know for sure that intelligent extraterrestrial life has not already been discovered." The new planet, so far unnamed, is 20.5 light years away and orbits a red dwarf star called Gliese 581.
What is a galaxy that doesn't have a regular shape called?
A galaxy that lacks a regular shape is called an irregular galaxy. Irregular galaxies do not have distinct spiral arms or a central bulge like spiral or elliptical galaxies. They often have a chaotic appearance with no clear structure.
What does AU55 NGC mean in coin collecting?
AU55 NGC is a coin grading designation provided by the Numismatic Guaranty Corporation (NGC) which signifies that the coin has been graded as Almost Uncirculated (AU) with a numerical grade of 55. This indicates that the coin has some wear but the original details are still visible. It falls between AU50 (less wear) and AU58 (more wear).
