The End of Everything

Written by Fraser Cain

Copy and paste from: http://www.universetoday.com/2007/07/25/the-end-of-everything/

It can be said that humans have a bit of a short term view of things. We're concerned about the end of summer, the next school year, and maybe even retirement. But these are just a blink of an eye in cosmic terms. Let's really think big, stare forward in time, and think about what the future holds for the Universe. Look forward millions, trillions, and even 10¹⁰⁰ years into the future. Let's consider the end of everything.

End of Humanity – 10,000 years
Modern humans originated in Africa about 200,000 years ago. Since then, we've gone on to inhabit every single corner of the globe. But this is just temporary. The vast majority of every species that has ever lived on Earth is now extinct. To think that humans can avoid the fate of every other creature is arrogant. Like all life on Earth, our time is limited. How long will we last?

There are many natural and man made disasters that could wipe us out. From an asteroidstrike to worldwide pandemic; global warming to a nearby supernova detonation – there are many ways we could go. Perhaps we'll wrap it up in a mass extinction event, such as the one that killed the dinosaurs 65 million years ago, or "the Great Dying", 251 million years ago that killed 70% of land species and 96% of all marine species.

Perhaps another species (intelligent cockroaches, rats) will evolve, and out compete with us in our niche. Or maybe we'll engineer our robotic replacements.

But a species can last tens or even hundreds of millions of years. So how can we predict when our number will be up?

There's no way to know, but there's a calculation that can help. It's called the Doomsday Argument, developed in 1983 by astrophysicist Brandon Carter. According to Carter, if you assume that half of the humans who will ever live have already been born, you get approximately 60 billion people. If you assume that another 60 billion are yet to be born, our high population levels only give us another 9,000 years or so. Or more precisely, there's a 95% chance that humanity will have ended by the year 11,000.

There are other calculations, but they give similar amounts, ranging from a few thousand to a few million years.

That's a long time, but not long enough to appreciate the future the Universe has in store for itself.

End of Life – 500 million years – 5 billion years
We thank the Sun for giving us energy. Without it, there'd be no life on Earth. It's ironic, then, that the Sun will eventually kill all life on Earth.

That's because the Sun is slowly heating up.

One of the most fascinating books about this topic is The Life and Death of Planet Earth by Peter Ward and Donald Brownlee. In their book, they chronicle how Sun's energy output is slowly increasing. In as soon as 500 million years, temperatures on Earth will rise to the point that most of the world will be a desert. The largest creatures won't be able to survive anywhere but the relatively cooler poles.

Over the course of the next few billion years, evolution will seem to go reverse. The largest organisms and least heat tolerant animals will die out, leaving hardy insects and bacteria. Finally, it'll be so hot on the surface of the Earth that the oceans will boil away. There'll be no place to hide from the terrible temperatures. Only the organisms that live deep underground will survive, as they have already for billions of years.

End of the Earth – 7.5 billion years
As mentioned above, we exist because of the Sun's good graces. But as our star nears the end of its lifetime, it'll take our planet out as it goes; one way or another.

In approximately 5 billion years from now, the Sun will begin the final stage of its life, consuming the last of its hydrogen fuel supply. At that point, gravity will force the Sun to collapse, and only a small amount of hydrogen will remain in a shell wrapped around thestar's core. It will then expand into a red giant star, consuming each of the inner planets: firstMercury, then Venus, and finally encompassing even the orbit of Earth.

There is a controversy about whether or not a red giant Sun will actually burn up the Earth. In some scenarios, the change in the Sun's density as it expands causes the Earth to spiral out away from the Sun, keeping out of reach. In another scenario, the Sun's outer envelope will enclose the Earth. The additional friction will slow the Earth down, causing it to spiral down into the Sun.

Whatever the outcome, the Earth will be scorched to a cinder, and effectively destroyed, 5 billion years from now.

End of the Sun – 7.5 billion – 1 trillion years
When the Sun becomes a red giant, that's only the beginning of the end. With the end of its hydrogen, the Sun will have switched to fusing helium, then carbon, and finally oxygen. At that point, our Sun will lack the gravity to continue the fusion process. It will shut down, and shed its outside layers to form a planetary nebula, such as the ring nebula we can see in the night sky. It'll then settle down to live out the rest of its days as a white dwarf.

It will still retain most of its mass, but have a size no larger than the Earth's diameter. Once yellow-hot with the heat of fusion, the Sun will slowly cool down over time. Eventually, its temperature will match the background temperature of the Universe and it will become a cold black dwarf – an inert chunk of matter floating in the darkness of space.

Even the oldest white dwarfs still radiate at several thousand degrees Kelvin, so the Universe hasn't been around long enough for black dwarfs to exist.. yet. But give the Sun another 1 trillion years or so, and it should finally become a cold black dwarf.

End ofthe Solar System
Even though the Sun will have burned out billions of years from now,the planetsthat weren't consumed will remain. Perhaps even Earth will join that group. Certainly Jupiter, Saturn, the rest of theouter planets and the Kuiper belt objects will remain orbiting for eons.

A recently discovery, published in the journal Science, reported that astronomers had discovered a disk of rapidly rotating metallic material orbiting a white dwarf. Researchers built a simulation where they put hypothetical planets in orbit around a dying star, and found that the star's death wreaked havoc on the stability of a star system. Changes in the mass of a star causes planets to collide, and rearrange their orbits. Some spiral into their star, while others are ejected into interstellar space.

Once all these new gravitational interactions are worked out, all that might remain of our solar system is the white dwarf remnant of our Sun and the rapidly rotating disk of planetary wreckage surrounding it. Everything else will be lost to interstellar space.

End of Cosmology – 3 Trillion Years from Now
The Universe acts as a natural time machine. Since light moves at the speed of, well, light, we can look at distant objects and see them how they looked in the past. Look to the very ends of the visible Universe, and you see light that was emitted billions of years ago, shortly after the Big Bang.

It's handy, but there's a problem. That mysterious dark energy force, which is accelerating the expansion of the Universe is making the most distant galaxies move faster and faster away from us. Eventually, they will cross an event horizon and appear to be moving away from us faster than the speed of light. At this point, any light emitted by the galaxy will cease to reach us. Any galaxy that crosses this horizon will fade away from view, until its last photon reaches us. All galaxies will disappear from view forever.

According to a new research paper by Lawrence M. Krauss and Robert J. Scherrer, future astronomers living 3 trillion years from now will only see our own galaxy when they look into the night sky.

This accelerating expansion has another consequence as well. The cosmic microwave background radiation, which astronomers used to discover evidence of the Big Bang will have faded away too. Not only that, but the abundance of chemicals, which precisely match the amounts theorized for the Big Bang will be hidden by subsequent generations of stars.

And so, 3 trillion years from now, there won't be any trace of the Big Bang. No clues for future cosmologists to recognize that the Universe we live in started from a single point, and has been expanding ever since. The Universe will seem static and unchanging.

End of the Milky Way
Galaxies collide. All you have to do is look out into space with a telescopeand see the fate that awaits our galaxy. In all directions we can see the interactions between the gravity of various galaxies. At first the encounters are violent; galaxies tear at each other, stripping off material, and generating huge swaths of star formation. The dormant supermassive black holes at their centres spring to live and become active galactic nuclei, gobbling up the newly delivered material.

Our future merger partner is barreling towards us right now: Andromeda. In approximately 2 billion years from now, our two galaxies will collide, and then pull apart. Then they'll collide again and again until they settle down into a new, larger galaxy: Milkomedia. The twin supermassive black holes will orbit one another, and eventually merge together into an even more massive black hole.

Our position in the galaxy will change; we'll probably be pushed out to the outer reaches of the galaxy's halo – at least 100,000 light years from the centre. Since the Sun will still have billions of years left, some future form of life on Earth might be around to watch these events unfold.

The merger process will be complete approximately 7 billion years from now.

That's not the end of the galaxy, though. It will still be an island in space, with stars orbiting a central core. Over a long period of time, though, estimated to be between 10¹⁹ 10²⁰ years. The galaxy will erode, with all the stars escaping into intergalactic space.

End of Stars – 100 trillion years from now
We can look out into the Milky Way and see stars forming all around us. There is still enough remaining gas and dust in the Milky Way to create whole new generations of stars. But when we look at other galaxies, we can see older, elliptical galaxies which have already used up their free gas and dust. Instead of the bright, hot stars we see in star forming regions, these aging red galaxies are cooling down.

One day there won't be newly forming stars at all. And then one day, the last star will use up the last of its hydrogen fuel, become a red giant and then fade away to a white dwarf. Even the dimmest stars, the cool red dwarfs will use up their fuel – although, it might taken another 10 trillion years or so. They too will turn into black dwarfs.

And so, in about 100 trillion years from now, every star in the Universe, large and small, will be a black dwarf. An inert chunk of matter with the mass of a star, but at the background temperature of the Universe.

The End of Regular Matter – 10³⁰ years
So now we have a Universe with no stars, only cold black dwarfs. There will also be neutron stars and black holes left over from the time where there were stars in the Universe. The Universe will be completely dark.

A future observer might notice the occasional flash, when some object interacts with a black hole. Its matter will spread out into an accretion disk around the black hole. And for a brief period, it will flare up, emitting radiation. But then it too will be added to the mass of the black hole. And everything will go dark again.

Chunks of matter and binary black dwarfs will merge together creating new black holes, and these black holes will be consumed by even larger black holes. It might be that in the far future, all matter will exist in a few, truly massive black holes.

But even if matter escapes this fate, it's doomed eventually. Some theories of physicspredict that protons are unstable over long periods of time. They just can't last. Any matter that wasn't consumed by a black hole will start to decay. The protons will turn into radiation, leaving a fine mist of electrons, positrons, neutrinos and radiation to spread out into space.

Theorists anticipate that all protons in the Universe will decay over the course of 10³⁰ years.

End of Black Holes – 10¹⁰⁰ Years
Black holes were thought to be one-way streets. Matter goes in, but it doesn't come out. But famed astrophysicist Stephen Hawking turned that concept on its head with his theory that black holes can evaporate. It's not much, and it's not fast, but black holes release a tiny amount of radiation back into space.

As it releases this radiation, the black hole actually loses mass, finally evaporating away entirely. The amount of radiation increases as the black hole loses mass. It's actually possible that it could generate a final burst of X-rays and gamma rays as it disappears completely. Future observers (who survived their protons decaying) might see the occasional flash in an otherwise dark universe.

And then in about 10¹⁰⁰ years, the last black hole will be gone. All that remains is the radiation emitted.

The End of Everything – 10¹⁰⁰ years and beyond
When the last black hole evaporates, all that will remain in the Universe are photons of radiation, and elementary particles that escaped capture by black holes. The temperature of the entire Universe will reach a final temperature just above absolute zero.

Dark energy may play some future role, continuing the expansion of the Universe, accelerating each of these elementary particles and photons away from each other until they're effectively cut off from one another. No future gravity will bring them together again.

Perhaps there will be another Big Bang someday. Perhaps the Universe is cyclical and the whole process will start up again.

Perhaps it won't, and this bleak future of a cold, dead Universe is all that awaits us. It's not happy, but it's awe inspiring to consider the long future ahead, and helps us appreciate the vibrant age we live in today.

Former ?10th planet? officially named Eris

Once known as Xena, mini-world ignited debate over planethood

The mini-world formerly known as 2003 UB313 or Xena, shown in this artist?s conception, has received an official name from the International Astronomical Union: Eris. Its moon has been named Dysnomia.

LOS ANGELES - A distant, icy rock whose discovery shook up the solar system and led to Pluto?s planetary demise has been given a name: Eris.

The christening of Eris, named after the Greek goddess of chaos and strife, was announced by the International Astronomical Union on Wednesday. Weeks earlier, the professional astronomers? group stripped Pluto of its planethood under new controversial guidelines.

Since its discovery last year, Eris ignited a debate over what constitutes a planet.

Astronomers were split over how to classify the object ? which had been known as 2003 UB313, its provisional numerical designation; or as Xena, the informal code name that was chosen by its discoverers. Some argued that it should be welcomed as the 10th planet since it was larger than Pluto, but others felt Pluto was not a full-fledged planet.

After much bickering, astronomers last month voted to shrink the solar system to eight planets, downgrading Pluto to a ?dwarf planet,? a category that also includes Eris and the asteroid Ceres.

Eris? discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it ?too perfect to resist.?

In mythology, Eris caused a quarrel among goddesses that sparked the Trojan War. In real life, Eris forced scientists to define a planet that eventually led to Pluto getting the boot. Soon after Pluto?s dismissal from the club of classical planets, hundreds of scientists circulated a petition protesting the decision.

Moon also gets an official name
Eris? moon also received a formal name: Dysnomia, the daughter of Eris known as the spirit of lawlessness. Dysnomia is the object formerly known by the code name Gabrielle.

While waiting for an official designation, Brown and his colleagues reportedly used Xena as a code name because it called to mind the term ?Planet X,? which commonly referred to a mysterious 10th planet. The name also alluded to the title character in ?Xena: Warrior Princess,? a syndicated sword-and-sorcery TV series.

?It?s a little sad to see Xena go away,? Brown said.

In the TV show, Gabrielle was Xena?s sidekick. Coincidentally, Eris was also the name of a character in ?Xena: Warrior Princess.?

The dwarf planet Eris, which measures about 70 miles (110 kilometers) wider than Pluto, is the farthest known object in the solar system at 9 billion miles (14 billion kilometers) away from sun. It is also the third brightest object located in the Kuiper Belt, a disc of icy debris beyond the orbit of Neptune.

Farthest known galaxy in the Universe discovered

HUBBLE EUROPEAN SPACE AGENCY INFORMATION CENTRE
Posted: February 15, 2004

An international team of astronomers may have set a new record in discovering what is the most distant known galaxy in the Universe. Located an estimated 13 billion light-years away, the object is being viewed at a time only 750 million years after the big bang, when the Universe was barely 5 percent of its current age.

A new galaxy (split into two ?images? marked with an ellipse and a circle) was detected in this image taken with the Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope. The extremely faint galaxy is so far away that its visible light has been stretched into infrared wavelengths, making the observations particularly difficult. Credit: European Space Agency, NASA, J.-P. Kneib (Observatoire Midi-Pyrenees) and R. Ellis (Caltech)

The primeval galaxy was identified by combining the power of the NASA/ESA Hubble Space Telescope and CARA?s W. M. Keck Telescopes on Mauna Kea in Hawaii. These great observatories got a boost from the added magnification of a natural ?cosmic gravitational lens? in space that further amplifies the brightness of the distant object.

The newly discovered galaxy is likely to be a young galaxy shining during the end of the so-called ?Dark Ages? - the period in cosmic history which ended with the first galaxies and quasars transforming opaque, molecular hydrogen into the transparent, ionized Universe we see today.

The new galaxy was detected in a long exposure of the nearby cluster of galaxies Abell 2218, taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. This cluster is so massive that the light of distant objects passing through the cluster actually bends and is amplified, much as a magnifying glass bends and magnifies objects seen through it. Such natural gravitational ?telescopes? allow astronomers to see extremely distant and faint objects that could otherwise not be seen. The extremely faint galaxy is so far away its visible light has been stretched into infrared wavelengths, making the observations particularly difficult.

?As we were searching for distant galaxies magnified by Abell 2218, we detected a pair of strikingly similar images whose arrangement and colour indicate a very distant object,? said astronomer Jean-Paul Kneib (Observatoire Midi-Pyrenees and California Institute of Technology), who is lead author reporting the discovery in a forthcoming article in the Astrophysical Journal.

Analysis of a sequence of Hubble images indicate the object lies between a redshift of 6.6 and 7.1, making it the most distant source currently known. However, long exposures in the optical and infrared taken with spectrographs on the 10-meter Keck telescopes suggests that the object has a redshift towards the upper end of this range, around redshift 7.

Redshift is a measure of how much the wavelengths of light are shifted to longer wavelengths. The greater the shift in wavelength toward the redder regions of the spectrum, the more distant the object is.

?The galaxy we have discovered is extremely faint, and verifying its distance has been an extraordinarily challenging adventure,? said Dr. Kneib. ?Without the 25 x magnification afforded by the foreground cluster, this early object could simply not have been identified or studied in any detail at all with the present telescopes available. Even with aid of the cosmic lens, the discovery has only been possible by pushing our current observatories to the limits of their capabilities!?

Gravitational lenses produce different shaped images depending on the shape of the lensing body. If the lens is spherical then the image appears as an Einstein ring ? a ring of light; if the lens is elongated then the image is an Einstein cross ? it appears split into four distinct images; and if the lens is a galaxy cluster, like Abell 2218, then arcs and arclets (banana-shaped images) of light are formed. Credit: European Space Agency

Using the combination of the high resolution of Hubble and the large magnification of the cosmic lens, the astronomers estimate that this object, although very small - only 2,000 light-years across - is forming stars extremely actively. However, two intriguing properties of the new source are the apparent lack of the typically bright hydrogen emission line and its intense ultraviolet light which is much stronger than that seen in star- forming galaxies closer by.

?The properties of this distant source are very exciting because, if verified by further study, they could represent the hallmark of a truly young stellar system that ended the Dark Ages? added Dr. Richard Ellis, Steele Professor of Astronomy at Caltech, and a co-author in the article.

The team is encouraged by the success of their technique and plans to continue the search for more examples by looking through other cosmic lenses in the sky. Hubble?s exceptional resolution makes it ideally suited for such searches.

?Estimating the abundance and characteristic properties of sources at early times is particularly important in understanding how the Universe reionized itself, thus ending the Dark Ages,? said Mike Santos, a former Caltech graduate student, now a postdoctoral researcher at the Institute of Astronomy, Cambridge, UK. ?The cosmic lens has given us a first glimpse into this important epoch. We are now eager to learn more by finding further examples, although it will no doubt be challenging.?

?We are looking at the first evidence of our ancestors on the evolutionary tree of the entire Universe,? said Dr. Frederic Chaffee, director of the W. M. Keck Observatory, home to the twin 10-meter Keck telescopes that confirmed the discovery. ?Telescopes are virtual time machines, allowing our astronomers to look back to the early history of the cosmos, and these marvellous observations are of the earliest time yet.?

Found 20 light years away: the New 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?.

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.