Astronomers Create 8 Million Baby Universes Inside A Computer

(THIS ARTICLE IS COURTESY OF LIVE SCIENCE)

 

Astronomers Create 8 Million Baby Universes Inside a Computer and Watch Them Grow. Here’s What They Learned.

helix nebula

(Image: © Shutterstock)

A team of astrophysicists has just spawned 8 million unique universes inside a supercomputer and let them evolve from just tots to old geezers. Their goal? To nail down the role that an invisible substance called dark matter played in our universe’s life since the Big Bang and what it means for our fate.

After discovering that our universe is mostly composed of dark matter in the late 1960s, scientists have speculated on its role in the formation of galaxies and their ability to give birth to new stars over time.

According to the Big Bang theory, not long after the universe was born, an invisible and elusive substance physicists have dubbed dark matter began to clump together by the force of gravity into massive clouds called dark matter haloes. As the haloes grew in size, they attracted the sparse hydrogen gas permeating the universe to come together and form the stars and galaxies we see today. In this theory, dark matter acts as the backbone of galaxies, dictating how they form, merge and evolve over time.

Related: The 11 Biggest Unanswered Questions About Dark Matter

To better understand how dark matter shaped this history of the universe, Peter Behroozi, an assistant professor of astronomy at the University of Arizona, and his team created his own universes using the school’s supercomputer. The computer’s 2,000 processors worked without pause over a span of three weeks to simulate more than 8 million unique universes. Each universe individually obeyed a unique set of rules to help researchers understand the relationship between dark matter and the evolution of galaxies.

“On the computer, we can create many different universes and compare them to the actual one, and that lets us infer which rules lead to the one we see,” Behroozi said in a statement.

While previous simulations have focused on modeling single galaxies or generating mock universes with limited parameters, the UniverseMachine is the first of its scope. The program continuously created millions of universes, each containing 12 million galaxies, and each allowed to evolve over nearly the entire history of the real universe from 400 million years after the Big Bang to the present day.

“The big question is, ‘How do galaxies form?’” said study researcher Risa Wechsler, a professor of physics and astrophysics at Stanford University. “The really cool thing about this study is that we can use all the data we have about galaxy evolution —  the numbers of galaxies, how many stars they have and how they form those stars — and put that together into a comprehensive picture of the last 13 billion years of the universe.”

Related: From the Big Bang to Present: Snapshots of Our Universe Through Time

Creating a replica of our universe, or even of a galaxy, would require an inexplicable amount of computing power. So Behroozi and his colleagues narrowed their focus to two key properties of galaxies: their combined mass of stars and the rate at which they give birth to new ones.

“Simulating a single galaxy requires 10 to the 48th computing operations,” Behroozi explained, referring to an octillion operation, or a 1 followed by 48 zeros. “All computers on Earth combined could not do this in a hundred years. So to just simulate a single galaxy, let alone 12 million, we had to do this differently.”

As the computer program spawns new universes, it makes a guess on how a galaxy’s rate of star formation is related to its age, its past interactions with other galaxies and the amount of dark matter in its halo. It then compares each universe with real observations, fine-tuning the physical parameters with every iteration to better match reality. The end result is a universe nearly identical to our own.

According to Wechsler, their results showed that the rate at which galaxies give birth to stars is tightly connected to the mass of their dark matter haloes. Galaxies with dark matter halo masses most similar to our own Milky Way had the highest star-formation rates. She explained that star formation is stifled in more massive galaxies by an abundance of blackholes

Their observations also challenged long-held beliefs that dark matter stifled star formation in the early universe.

“As we go back earlier and earlier in the universe, we would expect the dark matter to be denser, and therefore the gas to be getting hotter and hotter. This is bad for star formation, so we had thought that many galaxies in the early universe should have stopped forming stars a long time ago,” Behroozi said. “But we found the opposite: Galaxies of a given size were more likely to form stars at a higher rate, contrary to the expectation.”

Now, the team plans to expand the Universe Machine to test more ways dark matter might affect the properties of galaxies, including how their shapes evolve, the mass of their black holes and how often their stars go supernova.

“For me, the most exciting thing is that we now have a model where we can start to ask all of these questions in a framework that works,” Wechsler said. “We have a model that is inexpensive enough computationally, that we can essentially calculate an entire universe in about a second. Then we can afford to do that millions of times and explore all of the parameter space.”

The research group published their results in the September issue of the journal Monthly Notices of the Royal Astronomical Society.

Originally published on Live Science.

What Is the Universe Made of?

(THIS ARTICLE IS COURTESY OF LIVE SCIENCE)

 

What Is the Universe Made of?

Image of galaxy cluster Abell 2744 shows dark matter locations

In this image of galaxy cluster Abell 2744, a blue overlay shows the location of dark matter, which makes up about 75% of the cluster’s mass.
(Image: © NASA/ESA/ESO/CXC, and D. Coe (STScI)/J. Merten (Heidelberg/Bologna))

The universe is filled with billions of galaxies and trillions of stars, along with nearly uncountable numbers of planets, moons, asteroids, comets and clouds of dust and gas – all swirling in the vastness of space.

But if we zoom in, what are the building blocks of these celestial bodies, and where did they come from?

Hydrogen is the most common element found in the universe, followed by helium; together, they make up nearly all ordinary matter. But this accounts for only a tiny slice of the universe — about 5%. All the rest is made of stuff that can’t be seen and can only be detected indirectly. [From Big Bang to Present: Snapshots of Our Universe Through Time]

Mostly hydrogen

It all started with a Big Bang, about 13.8 billion years ago, when ultra-hot and densely packed matter suddenly and rapidly expanded in all directions at once. Milliseconds later, the newborn universe was a heaving mass of neutrons, protons, electrons, photons and other subatomic particles, roiling at about 100 billion degrees Kelvin, according to NASA.

Every bit of matter that makes up all the known elements in the periodic table — and every object in the universe, from black holes to massive stars to specks of space dust — was created during the Big Bang, said Neta Bahcall, a professor of astronomy in the Department of Astrophysical Sciences at Princeton University in New Jersey.

“We don’t even know the laws of physics that would have existed in such a hot, dense environment,” Bahcall told Live Science.

About 100 seconds after the Big Bang, the temperature dropped to a still-seething 1 billion degrees Kelvin. By roughly 380,000 years later, the universe had cooled enough for protons and neutrons to come together and form lithium, helium and the hydrogen isotope deuterium, while free electrons were trapped to form neutral atoms.

Because there were so many protons zipping around in the early universe, hydrogen — the lightest element, with just one proton and one neutron — became the most abundant element, making up nearly 95% percent of the universe’s atoms. Close to 5% of the universe’s atoms are helium, according to NASA. Then, about 200 million years after the Big Bang, the first stars formed and produced the rest of the elements, which make up a fraction of the remaining 1% of all ordinary matter in the universe.

Unseen particles

Something else was created during the Big Bang: dark matter. “But we can’t say what form it took, because we haven’t detected those particles,” Bahcall told Live Science.

Dark matter can’t be observed directly — yet — but its fingerprints are preserved in the universe’s first light, or the cosmic microwave background radiation (CMB), as tiny fluctuations in radiation, Bahcall said. Scientists first proposed the existence of dark matter in the 1930’s, theorizing that dark matter’s unseen pull must be what held together fast-moving galaxy clusters. Decades later, in the 1970’s, American astronomer Vera Rubin found more indirect evidence of dark matter in the faster-than-expected rotation rates of stars.

Based on Rubin’s findings, astrophysicists calculated that dark matter — even though it couldn’t be seen or measured — must make up a significant portion of the universe. But about 20 years ago, scientists discovered that the universe held something even stranger than dark matter; dark energy, which is thought to be significantly more abundant than either matter or dark matter. [Gallery: Dark Matter Throughout the Universe]

Hubble Space Telescope Image

Captured in 2014 by the Hubble Space Telescope, this picture of the evolving universe is among Hubble’s most colorful deep-space images.

(Image credit: NASA/ESA)

An irresistible force

The discovery of dark energy came about because scientists wondered if there was enough dark matter in the universe to cause expansion to sputter out or reverse direction, causing the universe to collapse inward on itself.

Lo and behold, when a team of researchers investigated this in the late 1990s, they found that not only was the universe not collapsing in on itself, it was expanding outward at an ever faster rate. The group determined that an unknown force — dubbed dark energy — was pushing against the universe in the apparent void of space and accelerating its momentum; the scientists’ findings earned physicists Adam Riess, Brian Schmidt and Saul Perlmutter the Nobel Prize in Physics in 2011.

Models of the force required to explain the universe’s accelerating expansion rate suggest that dark energy must make up between 70% and 75% of the universe. Dark matter, meanwhile, accounts for about 20% to 25%, while so-called ordinary matter — the stuff we can actually see — is estimated to make up less than 5% of the universe, Bahcall said.

Considering that dark energy makes up about three-quarters of the universe, understanding it is arguably the biggest challenge facing scientists today, astrophysicist Mario Livio, then with the Space Telescope Science Institute at Johns Hopkins University in Baltimore, Maryland, told Live Science sister site Space.com in 2018.

“While dark energy has not played a huge role in the evolution of the universe in the past, it will play the dominant role in the evolution in the future,” Livio said. “The fate of the universe depends on the nature of dark energy.”

Originally published on Live Science.

Our Galaxy’s Supermassive Black Hole Has Emitted a Mysteriously Bright Flare

(THIS ARTICLE IS COURTESY OF SCIENCE ALERT)

 

Our Galaxy’s Supermassive Black Hole Has Emitted a Mysteriously Bright Flare

MICHELLE STARR
12 AUG 2019

The supermassive black hole at the heart of the Milky Way, Sagittarius A*, is relatively quiet. It’s not an active nucleus, spewing light and heat into the space around it; most of the time, the black hole’s activity is low key, with minimal fluctuations in its brightness.

Most of the time. Recently, astronomers caught it going absolutely bananas, suddenly growing 75 times brighter before subsiding back to normal levels. That’s the brightest we’ve ever seen Sgr A* in near-infrared wavelengths.

“I was pretty surprised at first and then very excited,” astronomer Tuan Do of the University of California Los Angeles told ScienceAlert.

“The black hole was so bright I at first mistook it for the star S0-2, because I had never seen Sgr A* that bright. Over the next few frames, though, it was clear the source was variable and had to be the black hole. I knew almost right away there was probably something interesting going on with the black hole.”

But what? That’s what astronomers are on a mission to find out. Their findings so far are currently in press with The Astrophysical Journal Letters.

Do and his team took observations of the galactic center galaxy

using the WM Keck Observatory in Hawaii over four nights earlier this year. The strange brightening was observed on May 13, and the team managed to capture it in a time lapse, two hours condensed down to a few seconds.

Tuan Do@quantumpenguin

Here’s a timelapse of images over 2.5 hr from May from @keckobservatory of the supermassive black hole Sgr A*. The black hole is always variable, but this was the brightest we’ve seen in the infrared so far. It was probably even brighter before we started observing that night!

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That brightly glowing dot right at the beginning of the video is the dust and gas swirling around Sgr A*. Black holes themselves don’t emit any radiationthat can be detected by our current instruments, but the stuff nearby doeswhen the black hole’s gravitational forces generate immense friction, in turn producing radiation.

When we view that radiation with a telescope using the infrared range, it translates as brightness. Normally, the brightness of Sgr A* flickers a bit like a candle, varying from minutes to hours. But when the surroundings of a black hole flare that brightly, it’s a sign something may have gotten close enough to be grabbed by its gravity.

The first frame – taken right at the beginning of the observation – is the brightest, which means Sgr A* could have been even brighter before they started observing, Do said. But no one was aware that anything was drawing close enough to be swallowed by the black hole.

The team is busily gathering data to try and narrow it down, but there are two immediate possibilities. One is G2, an object thought to be a gas cloud that approached within 36 light-hours of Sgr A* in 2014. If it was a gas cloud, this proximity should have torn it to shreds, and parts of it devoured by the black hole – yet nothing happened.

The flyby was later called a “cosmic fizzle“, but the researchers believe the black hole’s May fireworks show may have been a delayed reaction.

sgr a s02(Do et al., arXiv, 2019)

But – have a look at the timelapse again. See that bright dot at around 11 o’clock from the black hole? That’s S0-2, a star on a long, looping, 16-year elliptical orbit around Sgr A*. Last year, it made its closest approach, coming within 17 light-hours of the black hole.

“One of the possibilities,” Do told ScienceAlert, “is that the star S0-2, when it passed close to the black hole last year, changed the way gas flows into the black hole, and so more gas is falling on it, leading it to become more variable.”

The only way to find out is having more data. They are currently being collected, across a larger range of wavelengths. More observations will take place over the coming weeks with the ground-based Keck Observatory before the galactic centre is no longer visible at night from Earth.

But many other telescopes – including Spitzer, Chandra, Swift and ALMA – were observing the galactic centre over the last few months, too. Their data could reveal different aspects of the physics of the change in brightness, and help us understand what Sgr A* is up to.

“I’m eagerly awaiting their results,” Do said.

The paper has been accepted into The Astrophysical Journal Letters, and is available on arXiv.

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

(THIS ARTICLE IS COURTESY OF ASTRONOMY TODAY)

 

Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

But even the venerable Hubble is incapable of seeing all that was taking place during the early Universe. However, using the combined power of some of the newest astronomical observatories from around the world, a team of international astronomers led by Tokyo University’s Institute of Astronomy observed 39 previously-undiscovered ancient galaxies, a find that could have major implications for astronomy and cosmology.

The team behind the discovery included members from Tokyo University’s Institute of Astronomy, the French National Center for Scientific Research (CNRS), the Anhui Normal University in China, the University of Ludwig-Maximilians in Munich, the National Astronomical Observatories of China, and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan. Their research appeared in the Aug. 7th issue of Nature.

Artist impression of galaxies detected by ALMA as they appear in the very early, very distant universe. Credit: NRAO/AUI/NSF; S. Dagnello

Spotting the “Invisible”

To put it simply, the earliest possible galaxies in the Universe have remained invisible until now because their light is very faint and occurs at long wavelengths that are undetectable by Hubble. The team therefore turned to the Atacama Large Millimeter/submillimeter Array(ALMA), whose telescopes are optimized for viewing this kind of light.

The discovery that resulted was not only unprecedented, but the discovery of this many galaxies of this type defies current cosmological models. As Tao Wang, a researcher from the AISAA and a co-author on the study, explained:

“This is the first time that such a large population of massive galaxies was confirmed during the first 2 billion years of the 13.7-billion-year life of the universe. These were previously invisible to us. This finding contravenes current models for that period of cosmic evolution and will help to add some details, which have been missing until now.”

These galaxies, though they were the largest in existence at the time, were still very difficult to spot. Much of the reason has to do with the extent to which their light has been stretched by the expansion of the Universe. In everyday astronomy, this phenomena is known as redshift, where the expansion of space (the Hubble Constant) causes the wavelength of light to become elongated, shifting it towards the red end of the spectrum.

This allows astronomers to not only tell how distant an object is, but what that object looked like in the past. But when looking to the very earliest epoch of the Universe (over 13 billion years ago) the immense distance stretches the wavelength of visible light to the point where it is no longer in the domain of visible light and becomes infrared.

NASA’s Spitzer Space Telescope captured this stunning infrared image of the center of the Milky Way Galaxy, where the black hole Sagitarrius A resides. Credit: NASA/JPL-Caltech

Another reason these galaxies are difficult to spot is that larger galaxies tend to be shrouded in dust, especially when they are still in the early parts of their formation. This tends to obscure them more than their smaller galactic counterparts. For these reasons, there was some suspicion that these galaxies were not as old as the team suggested. As Wang indicated:

“It was tough to convince our peers these galaxies were as old as we suspected them to be. Our initial suspicions about their existence came from the Spitzer Space Telescope’s infrared data. But ALMA has sharp eyes and revealed details at submillimeter wavelengths, the best wavelength to peer through dust present in the early universe. Even so, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”

What Does This Mean for Astronomy?

Since the discovery of these galaxies defies our current cosmological models, the team’s findings naturally have some significant implications for astronomers. As Kotaro Kohno, a professor with the Institute of Astronomy and a co-author on the study, explained:

“The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too,” added Kohno. “Massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now.”

Ancient galaxies from the study are visible to ALMA (right) but not to Hubble (left). Credit: Wang (et al.) 2019

Another interesting find was the ways in which these 39 ancient galaxies differ from our own. For starters, these galaxies had a higher density of stars than the Milky Way does today; which means that if our galaxy were similar, stargazers would be seeing something very different when they looked up at the night sky.

“For one thing, the night sky would appear far more majestic. The greater density of stars means there would be many more stars close by appearing larger and brighter,” said Wang. “But conversely, the large amount of dust means farther-away stars would be far less visible, so the background to these bright close stars might be a vast dark void.”

Since this is the first time that a galactic population of this kind has been discovered, astronomers are looking forward to what else they might find. As it stands, even ALMA is not sophisticated enough to investigate the chemical compositions and stellar populations of these galaxies. However, next-generation observatories will have the resolution for astrnomers to conduct these studies.

These include the James Webb Space Telescope, which is currently slated for launch in 2021. Ground-based observatories like the ESO’s Extremely Large Telescope (ELT), the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT) are also likely to play a vital role.

It’s an exciting time for astronomers and cosmologists. Ever so slowly, they are peeling back another layer of the Universe to see what secrets lurk beneath!

Further Reading: University of Tokyo

Space travel breakthrough: could cover 3.6 Million miles per day passes test

(THIS ARTICLE IS COURTESY OF THE UK EXPRESS)

Space travel breakthrough: Spacecraft which cover 3.6 Million miles per day passes test

A SPACESHIP which is so fast it could travel 3.6 million miles per day has been successfully tested in Earth’s orbit.

LightSail 2: Planetary Society demonstrates solar sail spacecraft

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The Lightsail 2 craft is an experiment to prove the practical application of a controlled ‘solar sail’, which has the ability to far outstrip traditional rocket engines. The revolutionary mission was launched on June 25 and developed by ‘The Planetary Society’, based in the US. The voyage became the first ever to demonstrate solar sailing and used energy from the Sun to orbit Earth.

The tiny 10x10x30cm spacecraft was powered with propelled sunlight bouncing off its mirrored sails.

The exploration used thin plastic sheets to gather the momentum from the Sun.

Most notably the spacecraft was able to manoeuvre without the need for fuel or engines.

science

The Lightsail 2 was successful in its orbit around Earth (Image: AP)

science

The voyage became the first ever to demonstrate solar sailing (Image: The Planetary Society)

Bruce Betts LightSail program manager and Planetary Society chief scientist hailed the groundbreaking mission.

Mr Betts said: “We’re thrilled to announce mission success for LightSail 2.

“Our criteria was to demonstrate controlled solar sailing in a CubeSat by changing the spacecraft’s orbit using only the light pressure of the Sun, something that’s never been done before.

READ MORE: Sun explosion: Terrifying moment Sun shockwave sends particles flying

Science

The exploitation used thin plastic sheets to gather the momentum from the Sun (Image: GETTY)

“I’m enormously proud of this team. It’s been a long road and we did it.”

Leading scientist and Planetary Society CEO Bill Nye said the mission was a “game-changer” for further space exploration.

He said: ”For The Planetary Society, this moment has been decades in the making.

“Carl Sagan talked about solar sailing when I was in his class in 1977. But the idea goes back at least to 1607, when Johannes Kepler noticed that comet tails must be created by energy from the Sun.

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Lightsail: An artist impression of the space craft in orbit

Lightsail: An artist impression of the space craft in orbit (Image: PA)

Lightsail: The designs were released on the launch of the spacecraft

Lightsail: The designs were released on the launch of the spacecraft (Image: PA)

“The LightSail 2 mission is a game-changer for spaceflight and advancing space exploration.”

The LightSail 2 is a crowdfunded mission and involved donations from 50,000 people from across the world.

Jennifer Vaughn Planetary Society CEO said the mission can be a “paradigm shift” to get more people involved in space missions.

Ms Vaughn said: “LightSail 2 proves the power of public support.

Lightsail: The Planetary Society tweeted out the last information emitted from the spacecraft

Lightsail: The Planetary Society tweeted out the last information emitted from the spacecraft (Image: TWITTER•@exploreplanets)

“This moment could mark a paradigm shift that opens up space exploration to more players.

“It amazes me that 50,000 people came together to fly a solar sail.

“Imagine if that number became 500,000 or 5 million. It’s a thrilling concept.”

In a statement on the Planetary Society Twitter account, the team wrote: “LightSail2 is now the highest performing solar sail to date and it’s 100% crowdfunded by our members and backers!”

History of solar sailing

• The idea for solar sailing dates back to the 17th century
• NASA came up with the plan for a solar sail to Halley’s comet in the 1970s
• Russia teamed up with the Planetary Society for a doomed solar test for Cosmos 1 in 2001 and 2005
• Japan launched Ikaros – the first solar sail flight in 2010
• LightSail2 was launched aboard SpaceX’s Falcon Heavy rocket in 2019
• LightSail2’s mission is to be the second-ever controlled solar sail flight and the first in Earth orbit

LightSail 2 has a limited lifespan and is doomed to be destroyed.

The spacecraft will eventually crash into the sun and burn as it continues its orbit.

The technology follows LightSail 1 which managed a much lower orbit on the same approach.

Ikaros: Japan's space craft was the first of its kind to carry out the journey

Ikaros: Japan’s space craft was the first of its kind to carry out the journey (Image: GETTY)

How Venus Turned Into Hell, and How the Earth Is Next

(THIS ARTICLE IS COURTESY OF SPACE.COM)

 

How Venus Turned Into Hell, and How the Earth Is Next

The bizarre and hellish atmosphere of Venus wafts around the planet's surface in this false-color image from the Japanese Aerospace Exploration Agency's Akatsuki spacecraft. Citizen scientist Kevin Gill processed the image using infrared and ultraviolet views captured by Akatsuki on Nov. 20, 2016.

The bizarre and hellish atmosphere of Venus wafts around the planet’s surface in this false-color image from the Japanese Aerospace Exploration Agency’s Akatsuki spacecraft. Citizen scientist Kevin Gill processed the image using infrared and ultraviolet views captured by Akatsuki on Nov. 20, 2016.
(Image: © Kevil Gill/JAXA/ISAS/DARTS/Flickr)

Paul M. Sutter is an astrophysicist at The Ohio State University, host of Ask a Spaceman and Space Radio, and author of “Your Place in the Universe.” Sutter contributed this article to Space.com’s Expert Voices: Op-Ed & Insights

Everyone wants to get off the planet Earth and go explore the solar system, without realizing just how good we’ve got it down here. We’ve got a lot of air, more liquid water than we know what to do with, a nice strong planetary magnetic field that protects us cosmic radiation, and nice strong gravity that keeps our muscles strong and our bones thick.

All things considered, Earth is pretty nice.

Related: What Would It Be Like to Live on Venus?

But still, we look to our planetary neighbors for places to visit and maybe even live. And Mars has all the attention nowadays: it’s so hot right now, with everyone practically climbing over each other’s rockets to get there in to build a nice little red home.

But what about Venus? It’s about the same size as the Earth and the same mass. It’s actually a little bit closer than Mars. It’s definitely warmer than Mars. So don’t why don’t we try going for our sister planet instead of the red one?

Oh, that’s right: Venus is basically hell.

Dante’s journey

It’s hard to not exaggerate just how bad Venus is. Seriously, imagine in your head what the worst possible planet might be, and Venus is worse than that.

Let’s start with the atmosphere. If you think that the smog in LA is bad, you should take a whiff of Venus. It’s almost entirely carbon dioxide and chokingly thick with an atmospheric pressure at the surface 90 times that of Earth. That’s the equivalent pressure of a mile beneath our ocean waves. It’s so thick that you almost have to swim through it just to move around. Only 4% of that atmosphere is nitrogen, but that’s more nitrogen total than there is in the Earth’s atmosphere.

And sitting on top of this are clouds made of sulfuric acid. Yikes.

Sulfuric acid clouds are highly reflective, giving Venus its characteristic brilliant shine. The clouds are so reflective, and the rest of the atmosphere so thick, that less than 3% of the sun’s light that reaches Venus actually makes it down to the surface. That means that you will only vaguely be aware of the difference between day and night.

But despite that lack of sunlight, the temperature on Venus is literally hot enough to melt lead, at over 700 degrees Fahrenheit (370 degrees Celsius) on average. In some places, in the deepest valleys, the temperature reaches over 750 degrees Fahrenheit (400 degrees Celsius), which is enough for the ground itself to glow a dull red.

And speaking of day and night — Venus has one of the most peculiar rotations in the solar system. For one, it rotates backward, with the sun rising in the west and setting in the east. Second, it’s incredibly slow, with one year lasting only two days.

Additionally, Venus once had plate tectonics that shut off long ago, and its crust is locked.

Yeah, Venus is hell.

Related: Photos of Venus, the Mysterious Planet Next Door

Straight to the inferno

So how did Earth’s sister end up so twisted?

Because Venus is made of pretty much the same stuff as our Earth, and has roughly the same size and mass, scientists are pretty sure that, back in the early days of the solar system, Venus was kind of nice. It probably supported liquid water oceans on the surface and white fluffy clouds dotting a blue sky. Actually, quite lovely.

But four and a half billion years ago, our sun was different. It was smaller and dimmer. As stars like our sun age, they steadily grow brighter. So back then Venus was firmly planted in the habitable zone, the region of the solar system that can support liquid water on the surface of a planet without it being too hot or too cold.

But as the sun aged, that habitable zone steadily moved outward. And as Venus approached the inner edge of that zone, things started to go haywire.

As the temperatures rose on Venus, the oceans began to evaporate, dumping a lot of water vapor into the atmosphere. This water vapor was very good at trapping heat, which further increased the surface temperatures, which caused the oceans to evaporate even more, which caused even more water vapor to get in the atmosphere, which trapped even more heat, and so on and so on as things spiraled out of control.

Eventually, Venus became a runaway greenhouse with all the water dumped into the atmosphere trapping as much heat as possible, with the surface temperatures continuing to skyrocket.

The liquid water that had been on the surface helped keep the tectonic plates nice and flexible, in a sense adding lubrication to the process of plate tectonics. But without the oceans, plate activity ground to a halt, locking the surface of Venus in place. Plate tectonics play a crucial role in regulating the amount of carbon dioxide in the atmosphere. Essentially, carbon binds to elements in dirt and rocks, and those dirt and rocks eventually get buried far beneath the surface over the course of millions of years as the plates rub up against each other and sink below each other.

But without this process, carbon that was locked in the dirt just slowly outgassed or dumped out in massive volcanic events. So, once the oceans evaporated, the carbon problem on Venus became even worse with nothing to sequester it. Over time, the water vapor in the atmosphere got hit by enough sunlight to break it apart, sending the hydrogen into space, with all that mass being replaced by carbon dioxide rising up out of the surface.

The once and future Earth

And as that atmosphere grew thicker, the conditions on the surface grew even more hellish.

The atmosphere might even have had enough drag to literally slow down the rotation of Venus itself, giving it its present-day sluggish rates.

Once this process was complete, which probably took 100 million years or so, the potential for any life on Venus was snuffed out.

And here’s the worst part about the story of Earth’s twisted sister. This is our fate, too. Our sun isn’t done aging, and as it grows older, it grows brighter, with the habitable zone steadily and inexorably moving outward. At some point within the next few hundred million years, the Earth itself will approach the inner edge of the habitable zone. Our oceans will evaporate. Temperatures will spiral upward. Plate tectonics will shut off. Carbon dioxide will dump into the atmosphere.

And by that time, our solar system will be home to not just one hell but two.

Learn more by listening to the episode “What Turned Venus Into Hell?” on the Ask A Spaceman podcast, available on iTunes and on the Web at http://www.askaspaceman.com. Thanks to @ross_trower, Russel S., and @papermonster12 for the questions that led to this piece! Ask your own question on Twitter using #AskASpaceman or by following Paul @PaulMattSutterand facebook.com/PaulMattSutter

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The biggest moons in our solar system

(THIS ARTICLE IS COURTESY OF TRIP TRIVIA)

 

The biggest moons in our solar system

Janus. Phoebe. Hyperion. Europa. Most of the planetary satellites in our solar system have cool names like these — names pulled mainly from ancient mythology. But our own natural satellite? In English anyway, the single moon that orbits our planet goes by the unimaginative name, “the moon.” Why?

It turns out the name “Moon” wasn’t lame until we started discovering satellites orbiting other planets, and we made the fatal mistake of calling them “moons.” It’s somewhat confusing that the proper noun “Moon,” derived from the old English word “Mona,” was co-opted to become a generic name for any planetary satellite.

Happily, languages other than English are not so afflicted. The Moon is known in Spanish as LunaSelene in Greek, Mweze in Swahili, and Kuu in Estonian.

Regarding the other satellites in our solar system whose names are higher on the cool scale: they come in all shapes and sizes, from irregular chunks of rock and ice to giant, complex spheres. Of the over 100 moons that have been observed in our solar system (with many more waiting to be discovered), here are the five largest.

5. Earth’s Moon

Credit: NASA / JSC

It happens that the fifth-largest satellite in our solar system is our own un-inspirationally named moon, at a diameter of 3,475 kilometers (about 2,160 miles).

Fun fact: It’s not by accident that the same side of the moon faces the Earth throughout its orbit: The moon rotates on its axis with the same period as its revolution around Earth. This phenomenon, called “tidal locking,” is caused by the influence of Earth’s gravity on the moon, and is not unique to the Earth-moon system; it is found in many other planetary satellites in our solar system.

4. Io

Credit: NASA / JPLUSGS

At a diameter of 3,636 kilometers (2,260 miles), Io is only slightly larger than our moon and orbits Jupiter. It’s Jupiter’s fifth-closest known moon, and was discovered in 1610 by none other than telescope inventor Galileo Galilei.

Fun fact: Io has over 400 active volcanoes on its surface, making it the most geologically active object in our solar system.

3. Callisto

Credit: NASA

Another of Galileo’s 1610 discoveries, Callisto also orbits Jupiter. At 4,800 kilometers (just under 3,000 miles) in diameter, it is almost the same size as the planet Mercury. Like our Moon, Callisto is tidally locked to its parent planet.

Fun fact: Although it is nearly the size of Mercury, Callisto has only one-third of Mercury’s density. This suggests that about half of Callisto is composed of water ice, and there may be a liquid-water ocean under the satellite’s crust.

2. Titan

Credit: NASA

The aptly named Titan is quite large indeed, at a diameter of 5,151 kilometers (3,200 miles). Unique among the many satellites in the solar system, Titan has an atmosphere, although you can’t breathe it: It’s 95 percent nitrogen and 5 percent methane. It was discovered by Dutch astronomer Christiaan Huygens in 1655.

Fun fact: Titan’s dense atmosphere causes a greenhouse effect that traps solar energy near the moon’s surface. Temperatures on Titan are a comparatively balmy −179° C (290° below-zero Fahrenheit).

1. Ganymede

Credit: NASA

Galileo was on a hot streak in 1610. In addition to finding Io and Callisto, he used his newly-invented telescope to spot Europa and Ganymede orbiting Jupiter.

To be fair, Ganymede was the low-hanging fruit in that bunch. At 5,268 kilometers (3,273 miles_ in diameter, Ganymede edges Titan for the “largest moon” honor; it is larger than not only Mercury but also Pluto, the one-time planet that was demoted to dwarf planet status in 2006.

Fun fact: Like Callisto, Ganymede is believed to have a water ocean beneath its crust that completely covers the moon’s interior.

The 2-minute guide to Chinese astrology

(THIS ARTICLE IS COURTESY OF TRIVIA GENIUS)

 

The 2-minute guide to Chinese astrology

Half the fun of eating Chinese food comes from both the cryptic predictions that sprout from the crunch of a broken fortune cookie and from poring over place mats adorned with the Chinese zodiac. From time immemorial, humanity has searched for meaning in the stars, and many Chinese cultures have read the celestial canvas with curiosity and deeply-held mysticism.

The wisdom of Jupiter

Credit: LV4260 / iStock

The Chinese zodiac is based on early observations of the orbit of Jupiter. It is because of this that the zodiac occurs in 12-year cycles in accordance with the 11.85 years of Jupiter’s orbital period. The Chinese zodiac was founded during the Zhou Dynasty (1046-256 B.C.) and found widespread practice and elaboration during the Han Dynasty starting in 2nd century B.C.

It was during this second renaissance that Chinese astrology incorporated the cultural pillars of the Yin and Yang from Taoism, the concepts of heaven and earth, and Confucian ethics. The principles of Chinese astrology remain an object of fascination to Western cultures and a strong practice in many East Asian nations, including China, Japan, South Korea, Vietnam, and Thailand.

Written in the stars

Credit: cfikker / iStock

The Chinese zodiac is based on a strong conviction in destiny predicted from the alignment of the planets during one’s birth.

Your birth year predicts your sign and dictates many aspects of your disposition, romantic compatibility, and relation with your elders. However, in addition to your birth year, your “inner animal” is dictated by month, “true animal” by birthday, and “secret animal” by hour of birth.

Each sign is also associated with a “fixed element,” which interacts with a cycle of elements recurring in 60-year periods. Your birth month is still considered to be one of the most important predictors of your fate and disposition. Because of this, a Chinese astrologer would need to know the specific timing of your birth for a precise prediction. Even then, it is sometimes observed that a person’s behavior conflicts with his or her zodiac. This conflict is known as Tai Sui or kai sui.

The signs

Credit: Delpixart / iStock

Each sign corresponds to a year in Jupiter’s 12-year orbital cycle and an associated fixed element, starting with the first orbital year:

  • Rat-Water
  • Ox-Earth
  • Tiger-Wood
  • Rabbit-Wood
  • Dragon-Earth
  • Snake-Fire
  • Horse-Fire
  • Goat-Earth
  • Monkey-Metal
  • Rooster-Metal
  • Dog-Earth
  • Pig-Water
  • Monday-Goat
  • Tuesday-Dragon, Pig
  • Wednesday-Horse, Rooster
  • Thursday-Rat
  • Friday-Rabbit, Snake, Dog
  • Saturday-Ox, Tiger
  • Sunday-Monkey

Trines

Credit: humonia / iStock
  • Wood/Spring is a period of growth and vitality.
  • Fire/Summer is a period of flowering and energy.
  • Earth represents a transitory state between seasons.
  • Metal/Autumn is a period of harvesting.
  • Water/Winter is a period of retreat.
  • First Trine – The Rat, Dragon, and Monkey fall under the first trine, associated with intellect, magnanimity, and charisma, but capable of manipulation, jealousy, and deceit.
  • Second Trine – The Ox, Snake, and Rooster belong to the second trine, characterized by endurance, hard work, modesty, and morality, but capable of self-righteousness, egoism, vanity, and judgment.
  • Third Trine – the Tiger, Horse, and Dog pursue idealism, true love, loyalty, and honor, but may befall rashness, anxiety, and stubbornness.
  • Fourth Trine – The Rabbit, Goat, and Pig of the fourth trine are believed to be characterized by calm and reason, often sensible, creative, and empathetic, but prey to naiveté, pedantry, insecurity, and pessimism.

Asteroid tsunami: Scientist’s dire warning to US coast over ocean impact

(THIS ARTICLE IS COURTESY OF THE UK EXPRESS NEWS)

 

Asteroid tsunami: Scientist’s dire warning to US coast over ocean impact

AN ASTEROID plunging into the Pacific Ocean would spark a tsunami that would wipe out “the entire west coast of North America”, a scientist warned.

Apophis: Astrophysicist forecasts an asteroid ‘tsunami’

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Apophis 99942 is a 370-metre-wide near-Earth space rock that caused a brief period of concern in December 2004 when initial observation indicated a probability of up to three percent that it could hit Earth on April 13, 2029. However, in 2006 scientists ruled that date out, determining that Apophis could pass through a gravitational keyhole – a tiny region of space where a planet’s gravity is altered. Researchers calculated it might set up a future impact exactly seven years later – on April 13, 2036.

However, the likelihood of a direct impact in 2036 is now all but impossible, with just a 1-in-150,000 chance of a collision in 2068.

Neil deGrasse Tyson warned what would happen if the rock did crash into Earth.

The American astrophysicist and author revealed his research during a public lecture with Ryan Watt in San Francisco in 2008.

He said: “In the era of observing the cosmos with technology, this will be the closest biggest thing we will ever see.

“The orbit we now have for it is uncertain enough, because these things are hard to measure, we cannot tell you exactly where that trajectory will be.

JUST IN: Rock bigger than Empire State Building shooting towards Earth

An asteroid could hit the Pacific Ocean

An asteroid could hit the Pacific Ocean (Image: GETTY)

Apophis poses a threat

Apophis poses a threat (Image: GETTY)

It sandblasts the entire west coast of North America clean

Neil deGrasse Tyson

“We know it won’t hit Earth, we know it will be closer than the orbiting satellites.

“But there is a 600-mile zone – we call it the keyhole – and if the asteroid goes through the middle of that it will hit the Earth 13 years later.

“It will hit 500 miles west of Santa Monica.”

He went on to explain how an impact in the ocean would cause a tsunami, adding: “If it goes through the centre, it will plunge down into the Pacific Ocean to a depth of three miles, at which point it explodes, caveatting the Pacific in a hole that’s three miles wide.

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Neil deGrasse Tyson has his own theory

Neil deGrasse Tyson has his own theory (Image: YOUTUBE)

“That will send a tsunami wave outwards from that location that is 50 feet high.

“Oceans don’t like having holes in them, so this three-mile-high wall does what? It collapses.

“It falls back into the hole sloshing against itself with such ferocity that it rises high into the atmosphere and falls back down to the ocean, caveating it again.

“This cycle takes about 50 seconds, you can calculate it.”

He then revealed the sobering prospects for North America in such a scenario.

Neil deGrasse Tyson offered a warning

Neil deGrasse Tyson offered a warning (Image: YOUTUBE)

Asteroids threaten life on Earth

Asteroids threaten life on Earth (Image: GETTY)

He continued: “So there you are on the beaches of Malibu and a tsunami comes in.

“The first wave needs a supply of water to exist, so the next wave actually sucks back on it to create itself.

“Whatever was there on the coastline is now brought back out to sea and the next tsunami brings it back to the shore.

“So what happens is, all the artificial stuff, all the houses, factories, they get churned into the force that sandblasts the entire west coast of North America clean.

NASA warn of ‘Empire State’ sized asteroid flying by Earth

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“It’s April 12, 2029, and if it threads the keyhole it will hit Earth on April 13, 2036.”

Despite his claims, the keyhole has since been determined to be less than 600 metres wide, meaning the possibility of Apophis passing through it is extremely unlikely.

In 2008, NASA reaffirmed the chance of Apophis impacting Earth in 2036 as being 1 in 45,000.

However, in February 2014, the odds of an impact on April 12, 2068, were calculated by the JPL Sentry risk table as 1 in 150,000.

Potentially habitable Earth-like planet discovered 31 light years away

(THIS ARTICLE IS COURTESY OF CBS NEWS)

 

Potentially habitable Earth-like planet discovered 31 light years away

What was once considered pure fantasy in movies like “Avatar,” is now looking a little more plausible. Earlier this week, NASA announced the discovery of a possible Earth-like planet, located just 31 light years away – a hop, skip and a jump in cosmic terms  – that may be able to support life.

“I think it’s an amazing discovery,” Lisa Kaltenegger, from the Carl Sagan Institute at Cornell, said. “We have a small mission called ‘Tess’ that’s scanning the whole sky, where the brightest and closest objects are, to find planets like ours and this is the first one.”

The planet named GJ 357 d, is six times larger than Earth. It orbits a dwarf star with two other previously unknown planets.

This potential “super Earth” is located within the outer edge of its star’s habitable zone, where it receives about the same amount of stellar energy as Mars does from the sun. If this planet has a dense atmosphere, it could trap enough heat to allow for liquid water on its surface.

“You have a huge planet, so basically a chubby cousin, if you will,” Kaltenegger said. “Then you’d expect there to be a lot of atmosphere and that atmosphere again could capture that heat and make it warm enough for there to be liquid water.”

This amazing discovery was made possible by NASA’s Transiting Exoplanet Survey Satellite or TESS for short, but that spacecraft just pointed the way.

Two next-generation telescopes, coming online in the next six years, promise a much more detailed view, including whether the planet has mountains or oceans just like here on Earth.