The Fermi Paradox

Posted on April 27, 2017 by elliottlifeastronomy

“Where are they?” asked Enrico Fermi to his colleagues in 1950.  Where is all the life that, by all rights, should populate our galaxy and the rest of the universe?  The Fermi Paradox arises from the knowledge that the whole of human history is but a blip in the cosmic calendar.  If we have so quickly evolved and nearly made it to the reality of interstellar travel, then it stands to reason that the universe and our galaxy should be teeming with life.  According to Fermi’s math, the galaxy should have produced countless versions of intelligent life, some existing long before our own, and that logically Earth should have been visited repeatedly by extraterrestrials by now.

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Enrico Fermi: image from wikipedia

So where could they be if life should be so common?  Perhaps life as we know it is far less common than we believe- maybe the Earth and its inhabitants are extremely unique in our universe.  Maybe civilizations are too far apart in both space and time for us to ever make contact outside of our solar system.  Or perhaps life is out there, but its essence is so foreign to us that we wouldn’t even know if we found it.  There is another, slightly scarier, option though.  Perhaps life- even intelligent life- is quite common among the stars.  And maybe what keeps them from populating the galaxy is some catastrophic event that very few, or none, survive.  We’d never know until it happened to us.  But it’s nothing that we can really worry about.  All we can do is keep on keeping on down on Earth and exploring our sky to find out the facts.

Source: wikipedia


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The Comet Time Forgot… Until Now

Posted on April 27, 2017 by vmorehead0

A stone carving at a major archaeological site suggests a comet struck Earth thousands of years ago and started an ice age.

Göbekli Tepe is an archaeological site located in modern-day Turkey.  Built before Stonehenge, it served as an ancient temple site and religious center where multiple people would gather, but it also seemed to have been an astronomy observatory.   Archaeologists have studied several stone carvings at Göbekli Tepe.  The Vulture Stone, however, depicts a major astronomical event that changed human history.

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Replica of the Vulture Stone at Göbekli Tepe

The Vulture Stone depicts an ancient comet impact.  Archaeologists found the vultures and animals featured on the pillar correspond with ancient constellations and the comet.  They traced the positions of the constellations to around 10,950 BC, nearly 13,000 years ago.  This is also the date when a mini ice age called the Younger Dryas began.  The comet impact could have caused this ice age.

What happened was that the comet’s nucleus broke apart and struck the Earth.  The carving of a man with a missing head might indicate a significant loss of human life.  The ice age that followed led to the rise of agriculture.  The barley, wheat, and animals that hunter-gatherers relied on were in short supply during the Younger Dryas.  Humans had to resort to settling down, growing their own vegetables and fruits, and raising livestock.  The Younger Dryas herald a new age in human development, one where agriculture led to rise of villages, cities, and civilizations.  And it all could be attributed to this one comet impact.

 

Sources: Ancient stone carvings confirm how comet struck Earth in 10,950BC, sparking the rise of civilisations

Ancient Stone Carvings Show a Comet Swarm Hitting Earth Around 10,950 BCE

 

 

 


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Drake Equation

Posted on April 27, 2017 by liuy54

You may have heard of the Drake equation before, and you may have heard that it can “predict” the number of aliens we may one day face (or fight?). Well, you’re not too far off. The Drake equation allows astronomers and scientists to estimate the number of civilizations that exist in the deep vast space of the Milky Way beyond the boundaries of our solar system. First conceived by Dr. Frank Drake in 1961, the equation identifies many of the parameters and factors that can influence the estimate of civilizations we may discover. The idea of the equation was not to solve for the correct number of civilizations, but rather to generate discussion and dialogue among scholars at the SETI (search for intelligent extraterrestrial life). A pretty neat concept and equation! Here it is in all its glory

N = R* ⋅ fp ⋅ ne ⋅ fl ⋅ fi ⋅ fc ⋅ L

N =  The number of civilizations in the Milky Way Galaxy whose electromagnetic emissions are detectable.

R* = The rate of formation of stars suitable for the development of intelligent life.

fp = The fraction of those stars with planetary systems.

ne = The number of planets, per solar system, with an environment suitable for life.

fl = The fraction of suitable planets on which life actually appears.

fi = The fraction of life bearing planets on which intelligent life emerges.

fc = The fraction of civilizations that develop a technology that releases detectable signs of their existence into space.

L = The length of time such civilizations release detectable signals into space.

drake-frank-at-board-540px

Dr. Frank Drake and his Equation


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Blog 8: Possible Picture of a Black Hole

Posted on April 27, 2017 by vandyastro

Scientist have tried to take a picture of a black hole by creating a massive telescope. This telescope used radio wave based telescopes connected all over the world to create an earth sized telescope which may have the power to actually take a picture of a black hole. While this picture will not truly be of a black hole, since no light escapes it, it will be a portrait of the event horizon. This image has been taken over a five-night period. The amount of data received over this period will take months to process. This image will allow for test of Einstein’s Theory of gravity in extreme environments. This image could prove the existence of black holes, something monumental in the world of physics and astronomy.

 

While this image is not yet available here is an artist interpretation.

 

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Sources:

Information


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New Alien Planet

Posted on April 27, 2017 by Haley Topper

Recently, there was a new world discovered that is quite Earth-like. It is an exoplanet named OGLE-2016-BLG-1195Lb. This planet is about as massive as our earth, and orbits its start at around the same distance as earth orbits our sun, however, there is a major difference. The star that our new exoplanet orbits is tiny and dim, making the exoplanet most likely way too cold to actually host life (although maybe we could find an extremophile here?).

OGLE-2016-BLG-1195Lb lies a whole 13,000 light years away from us, and it was discovered using gravitational microlensing. Essentially, when a massive body passes in front of a star, gravity bends and magnifies the stars light. This new exoplanet is the lowest-mass planet ever found through microlensing. It turns out that the tiny star that hosts this exoplanet is only 7.8 percent of the mass of the Earth’s sun. While this exoplanet may not be sufficient enough for us to live, it may house microorganisms that could produce life!


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Blog 7: Last Universal Common Ancestor

Posted on April 27, 2017 by vandyastro

The Last Universal Common Ancestor, LUCA, was a microbe that live around 4 billion years ago. It is believed that it is anaerobic and autotrophic, not breathing and making its own food. There is also evidence it live near iron-sulfur rich hydrothermal bents deep underground. it would have possessed a metabolism dependent upon hydrogen, carbon dioxide, and nitrogen, then after using these it would turn them into ammonia and other organic compounds. this microbe is what we all can relate back too. To find LUCA, we will study the genetic tree of life, by following the genes, to revel the genetic relationship and evolutionary history of organisms, this is called phylogenetics.

By studying LUCA, they have looked for universals genes found in all genomes, and have found about 30 genes that belong LUCA. By looking at ancient genes that have exceptionally long lineages but have not been shared by lateral gene transfer, has found 355 genes which belonged to LUCA. While this is too small a number of genes would not support life but this is just the being. these small number of genes can tell us that LUCA lived in hydrothermal vents.

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Field of hyrothermal vents known as Loki’s Castle, this is the same type of environment that the LUCA is believed to have lived in.

Sites:

Infomation


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Astronomy and Us

Posted on April 27, 2017 by ksun1

“I believe our future depends powerfully on how well we understand this Cosmos, in which we float like a mote of dust in the morning sky.” – Carl Sagan

Even after learning all of the mysteries, all of the answers, all of the beauty, and all of the chaos of the universe, it is still natural to ask a question: why do we care?

And it’s a good question. After all, astronomy is literally an otherworldly science. Why should we care about the universe? The winds and storms of Jupiter have no effect on our little ball of rock. The supernovae and black holes that pervade our universe don’t harm us – and even if they did, we would be powerless anyway to stop them. So why does it matter?

This thing looks cool, but it will never affect you. Or your children. Or your children’s children.

It is true that many things astronomers study do not affect Earth in any way, and probably never will. However, only by studying everything that we can could we hope to understand how the universe operates. We, after all, live in this universe, and learning what makes its gears turns could certainly help us in the future – which we very well may need.

The Global Catastrophic Risk survey lists our chance of extinction by the year 2100 to be 19%. Our risk of being extinguished, at least, from this planet, due to strictly natural causes is almost guaranteed within the next few million years. The sad fact remains that if the human race has any long-term hopes of survival, we simply cannot stay on this planet forever. Collisions will occur. Eruptions will sweep the surface. The Sun will expand. Earth will die. What a truly unfortunate end it would be, if our future great great great . . . great grandchildren had to tell their sons and daughters that there is no hope…all because we refused to study the cosmos above.

But there is a more fundamental reason. Astronomy isn’t simply the study of stars and planets. It’s the study of the universe – of our home. We live in this universe, after all. We follow its laws of physics, we see glimpses of what else it has to offer, and yet we are stuck tantalizingly on this watery sphere we call Earth, with merely dreams of one day venturing out and seeing the wonders of the universe. We’ve dreamt about the universe for the entirety of human existence, creating myths, religions, or worship out of the skies above. For the first time in human history we now realize that we have the ability to learn more about our universe – our home. Why should we not? It doesn’t need to affect us. We don’t need to control it.

Knowledge, in itself, is a treasure alone.

 


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Fermi Paradox

Posted on April 27, 2017 by Haley Topper

Named after Enrico Fermi, the Fermi paradox essentially asks the question: Where are the aliens? If you think about it, there are tons of stars in the galaxy. Billions that are similar to our sun! Many of these stars are older than our earth and most likely have some earth-like planets around them. Therefore, there is a high probability that, at some point, these earth-like planets would develop life.

While it is taking us some time to develop interstellar travel, knowing that many of the stars around us are billions of years older than our earth, it’s not crazy to think that intelligent life could have developed and can travel to us by now. So, with all of these points, we have to ask: Where are the aliens?? If finding a planet with the conditions for life is more probable than we think, then why have we not been visited by aliens before? Or have we?

Do you think that we have been visited by aliens before?

 

Source: Space.com


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Alien Life on Enceladus

Posted on April 27, 2017 by aliyazd1407
Could there be life in the Solar System other than Earth? According to NASA, there might be life in one of the oceans in the Solar System. I’m pretty sure that this question make you wonder which ocean is that? The answer is ocean in ENCELADUS.
PIA17202 - Approaching Enceladus.jpg
Enceladus from Wikipedia

Before I proceed on why there is potential life on Enceladus, let me introduce what is Enceladus first. Enceladus is the sixth largest moon of Saturn (about a tenth of Titan, Saturn’s largest moon).

In 2008, Cassini has discovered that Enceladus has a global subsurface saltwater ocean and now, molecular hydrogen which is one of the crucial things of life, has been found in the plumes of liquid shooting out from its surface. The presence of hydrogen is essential for microbes because they can use this gas to obtain energy by combining it with dissolved carbon dioxide (this process known as methanogenesis).

Enceladus Layers by WIRED

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Why is the Solar System Flat?

Posted on April 27, 2017 by kic27

The Earth certainly isn’t flat, but the solar system it lives in very largely is. Our solar system formed from a giant ball of gas and dust billions of years ago, so what caused it to flatten out over time? The short answer is a combination of two factors: collisions and angular momentum. As the giant cloud of material contracts due to gravity, overall angular momentum must be conserved, causing the whole cloud on average to spin. As collisions occur, all of the motion not along this spinning plane tends to cancel itself out, leaving behind the flat disk structure we see today. Very similar mechanics are also present in the formation of other stellar objects like galaxies and planetary rings. To better explain this phenomenon, below is a video from the ever-excellent YouTube channel Minute Physics:

Video Source


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