It's almost identical to our sun in age, size, temperature and chemistry, has the same mass as our sun, and also formed with the same chemical recipe. This star was equipped in the same way as the sun to form  Earth-like planets. Its 126 light-years away. Its about 4 billion years-old. Do you think this star is old enough to develop some kind of complex life, assuming the time-scale for complex life formation is similar to Earth's? What kind of life would it be?
216000
I actually did hear about that in my college Astronomy class. I think it's pretty awesome. I mean, what if our sun burnt out. Maybe we could still have a significant amount of solar energy and radiation that could help us survive. I'm not sure if the star is old enough to develop life or not. It could have already developed it, and we just have no knowledge of it.
153306
I think that the extiction of earth is true maybe.  \n\nAll stars "fade" or die away eventually.  Well, we all know the sun is a star.  (biggest star :)) \n\nThus, the sun (star) is going to eventually die away.  Humans can not live without enery source from the sun.  Thus that's why scientist say that the earth is going to be extincted or whatever.\n\nAnyway, that's from like 5th grade or something... i'm in 6th now...\n\nwww.diamondgemztone.piczo.com\n<>dia gemz\nsheri
155750
throughout a stars life-cycle, it is constantly heating materials (hydrogen and iron) and pushing them to the surface to cool, and to the center to heat up and melt.\nThis is part of nuclear fission.\n\nafter a very long time, the sun starts to lose energy, and cant push the iron up from its core and gradually grows larger, turning red (hence red giant),\nEventually, the pressure from its mass, and it's failure to push it all away from its core will result in the star collapsing into itself, potentially turning into a black hole.
86877
Life would be hazardous there with jets of positrons from an unknown source and radiation all over the place.\nTowards the center of the galaxy the star population is alot denser than it is out here so there would be a greater risk for a planet there to be exposed to the full blast of a supernova. Supernovas would be devastating to life. It doesn´t matter what elements you are made up of or how many noses you got. The magic ingredient for making life is time. The primordial soup that where the earths oceans was carefully stewed for 800 million years before life developed. In the angry environment that is the center of the galaxy such stability is unlikely to be found.
292502
Nice question....stars shine because it is millions of light year away from us...in the case of planets its nearer than stars...not sure though..but i think so...
111120
Certainly.  While life of any sort is unlikely to be found in our solar system (at least beyond the possible existance of bacteria or bacterial fossils) the universe is simply too large for life to not occur somewhere else.\n\nAssuming that life on earth formed and evolved from the basic chemicals of a primordial earth into molecules, and the single celled organisms, it is entirely possible that this could happen somewhere else.  As was previously mentioned, there are a huge amount of stars in the universe, all of which may hold the potential to support a solar system with planets and create conditions likely to that of the Earth 4.5 billion years ago.  Even with a low frequency (1 in billions or more) of any sort of life-form formation, this means what there would likely be life in many places throughout the universe.\n\nI believe that experiments have been performed simulating the primordial chemical environment of the Earth, and subjecting it to electric discharge as would be released by lightning.  It was found that simple compounds such as amino acids could be formed from these reactions, and thus the formation of life may be viewed as a statistical event with a decent probability of occurance, given the correct conditions.\n\nWhile the chance of life existing is significant, the chance of it being intelligent interacting life-forms that we are able to find is much lower.  Even traveling at the fastest speed possible (speed of light), which has never been close to attained for human flight, it would take 15 billion years to reach the outskirts of the universe.  Assuming that life may undergo cycles in which a life-form may evolve, deplete a planet's resources, and then die out, the window of opportunity for finding any life form may be small.  Additionally, since prospective planets to explore that may contain life are likely identified by telescopes, the telescopes show what the planet was like in the past due to the time it takes the light to travel to the Earth.  If we are looking at a planet that is 5 billion light years away, we are looking at the light that was sent from that planet 5 billion years ago.\n\nWhile there are many formidable obstacles, it is not altogether impossible for us to find life on other planets, but I doubt that any of us will see it in our lifetimes.
596461
The sun is about 4.5 billion years old and about 1/3 rd the way through it's expected life. Scientists have given us a glimpse of what to expect as the sun ages.\n\n1.1 billion years or so, it will become 10% brighter. This will cause the earth to become super heated, all life will be destroyed and the oceans will boil away. Then in another 6.5 billion years, it will double in brightness and burn its supply of hydrogen fuel in its core. The sun will swell and become bigger than what we see today.\n\nAt around 8 billion years or so, the size will increase to 166 times and reach as far as Jupiter. The color will be red and it will be known as a Red Giant, but once the hydrogen fuel is depleted and the sun has reached the outer regions of Jupiter, it will start to shrink, losing both energy and brightness as it quickly consumes it's helium in  in 100 million years or so..\n\nThen, at around 12 billion years, the sun will eject much of its outer layers and become a smoldering, collapsed core that scientists would call a White Dwarf, but this is not the end, for it has one more transformation. It eventually will become a Black Hole.\n\nIf you would like to see what the sun will look like when it becomes a White Dwarf, go to:\nhttp://www.physorg.com/newman/gfx/news/m2_9_large.jpg
299050
Yes (personal judgment)\n\nwith the size of the universe as it is, it would be ignorant and elf-centered to say no. Especially since the sun is a mediocre star and the earth is a mediocre planet even in our system... Now, practically...\n\n-- Astronomers found planets by other stars, but not the size of Earth (too small for what we can detect now)\n-- the next star over is about 5 light years away? (not sure) so even if we travel at 99.999...% of light speed (as we are not massless) it would take ten years and trillions of trillions of dollars/Euro/tugrics, whatever you like. That is even if that star can support life.\n-- no reason to assume that there is multicellular life anywhere close, and if there is no reason to assume they are more advanced.\n-- Popular Science actually had an article last month on a non-DNA based "unicellular" primitive life that could have entered Earth on a small meteor. This is an idea scientists have been toying around with for a while. From my highchair it is possible, but I really don't know enough to say how probabble, afterall the space is mighty cold and the entery of our atmosphere mighty hot. Some say new viruses (which are not alive as virus is not a living entety) enter Earth in that way... that is doubtful since the DNA can't stand more than 50 degrees and the virus shell denatures at 42 (all in Celsius)\n\nI think there is life elsewhere but we will never see it... \n\nIf you have any more info or comments or just want to chat on this subject email me, I like interesting conversations.
479764
Well the sun doesn't become a red giant for a while so maybe we've made some friends by then and can go hang out near their home planet if it hasn't also been ruined.  It is likely that we will be much better at terraforming and travel so hoping over to a good canidate planet where we wouldn't be destroying life that already existed there shouldn't be too difficult a task.
607903
You are correct!\n\nYes, depending on how far away the star is, we are looking at it as it was one million years ago (if it is 1 million light years distant). So, we are looking backwards into time, when we look out into distant space.\n\nThe sun is 8 light-minutes away from Earth...so if you are outside, and you can see the sun in the sky...it may have vanished five minutes ago, and we wouldn't even know it for three minutes!!\n\nThe quasars are the strangest of all objects in the universe. They are apx. 10 to 15 billion light years away from us...so that means that they are extremely ancient. Perhaps, they are as old as the universe itself.
609219
So far, we can only detect fairly large planets around nearby stars in our own galaxy.  However, the number of planets we are discovering shows us that planets are very common.  There is no reason to think that other galaxies would be any different.\n\nWe don't have sensitive enough tools yet to detect Earth-like planets, but they probably exist. We don't yet know how common life, intelligent or otherwise, is in the universe, but considering how many galaxies there are and how many stars in each one, it seems as though there should be other intelligent beings out there somewhere.
424078
It is estimated that Earth is bombarded by a city-sized asteroid once every 65mil yrs.\ni) Assuming a Poisson distribution, find the probability that Earth will be hit by 2 or less of such asteroids in the next 10000yrs.\nEta Carinae is a suspected hypernova that is 7000 light-years away from Earth. Scientists have observed 200 of such star in many distant galaxies. It was found that the stars have an average life-span of 200mil years with variance 2500mil yrs^2.\nii) Construct a 95% confidence interval for the mean lifespan of Eta Carinae, giving your answer correct to 8 significant figures.\nIt was found later that Eta Carinae was formed 200.01mil yrs ago. \niii) Using the sample of 200 stars earlier, a scientist boldly claimed that Eta Carinae will explode today, causing devastation to Earth in 7000years’ time. By stating clearly the null and alternate hypothesis, test the scientist's claim at 5% level of significance.\nYou may assume the normality of the population of stars observed.
437797
During most of the lifetime of a star, it neither expands nor contracts.  The gravitational attraction is balanced by internal pressure.  The internal pressure in our Sun comes from the density and temperature of the particles (atomic nuclei and electrons) in the plasma.\n\nThe temperature is maintained by the energy released by nuclear fusion in the core.  If this fusion stopped, the interior of the Sun would cool over a period of about a million years, and it would begin to contract.  (Once it contracted enough, it would begin to fuse helium instead of hydrogen and it would re-expand.)
294246
Ah, lots of planets have water, it's a very common substance, however imn out solar system it's mostly ice. life as we know it needs floating water. Mars might have had this, but it looks like the climate on Mars took a wrong turn a few billion  years ago. THere might still be life there in the form on single cell organisms, but we need to be able to drill down the ground to find out. Europa is also a candidate for life asn it seems that it has floating water under it's cover of ice (2 - 3 km deep!). \n\nThere might be live in other solar system, but its very hard for us to see, so far we can only find huge planets around other stars, not planets like ours, but in a few years we should be able to see them and then we might be able to see if they contain oxugen and or methane, which can be an indication that life is present, however to be sure we must go there, which we unfortunatelly wont be able to do in a very long time
437600
What the hell? The sun will not become a neutron star or black hole and we wouldn't freeze! people are seriously making stuff up lol! The sun would first expand into a red giant. This is because it runs out of Hydrogen in it's core and so starts burning Helium, and then other elements. When it expands it will pretty much vapourise the inner planets including the Earth, but this won't happen for another 5 billion years don't worry. After expanding the sun will collapse in, until it becomes a white dwarf. This is a much smaller star (essentially made mostly from the sun's core), and although at first very hot as it's surface area has decreased so the heat is concentrated more into one place, it will slowly cool until it is just a dead star. Stars around 1.4 solar masses or more become neutron stars, as they have enough mass and so enough gravity to squish all the atoms really close together and become very dense when they collapse in on themselves. Stars of 3 solar masses or more collapse so much they become black holes- the gravity completely takes control and squishes the entire star into a point of infinite density from which not even light can escape! But the Sun is not massive enough to do either of these. It is about an average sized star.
103142
There are ~200,000,000,000 stars in our galaxy. There are at least 80,000,000,000 galaxies in the universe, and reasonable estimates are from 80 billion to 400 billion. Estimates of the total number of stars in the universe that I've seen start around 3 followed by 16 zeroes, and a reasonable approximation would be in the neighborhood of 4.8 x 10^22.\n\nNow, we don't know of a single star that is known to NOT have planets; in fact, any planet within an order of magnitude or two of the mass of Earth is far too small for us to even detect, with the exception of those in very unusual systems, such as the one in the link below, which orbits a pulsar (it's also 1/5 the mass of pluto, but even if it were Earth-sized, a pulsar probably wouldn't be very conducive to life forming).\n\nWe also don't know exactly what conditions it takes to form life, how long those conditions need to last, or how long planets normally stay within that range of conditions.\n\nHowever, we can make some estimates.\nThe sun is a G-type star, and, although F-K type stars might be capable of supporting life (and such make up ~64% of the stars in the galaxy), we'll ignore everything but the 18.7% of stars which are G-type.\n\nFurther, let's say that only 1 in 10,000 G-type stars has a planet capable of forming life.\n\nNow, there is, on average, about 1 supernova per galaxy per century, so we'll have to eliminate some candidate stars on that; say about 99% of eligible stars do not form life as a result of radiation bombardment from nearby supernovae.\n\nThen, let's estimate that it takes 100,000,000 years for life to form, and the average planet only has 4,000,000,000 years of its lifespan where life can survive. Then, we have to figure out how many planets have life at any given time. The approximate lifespan of the sun is 10 billion years, so we'll figure that's about average for a G-type star.\n\nWe'll assume that no star has more than one habitable planet, and that no life colonizes any other planets. Then, we'll figure that only 1% of the planets which are still eligible actually have life.\n\nThat still leaves 3-4 planets currently inhabited, in our galaxy alone, including Earth. Multiply that by, oh, say, 1% of the minimum number of galaxies in the universe (just for the fun of it), and we still get nearly 3 billion currently inhabited planets.\n\nSo, I'd say that the answer is a pretty resounding "yes". Although most of them would be extinct long before we could concievably detect their existence, and even if not, they would be extinct for many millenia before we could communicate with them.
61851
no...stars are not planets, they are comprised primarily of extemely high and volatile gases that burn without oxygen.