Archive for the ‘Space and Time’ Category

By Irene Klotz

Ice plumes shooting into space from Saturn’s ocean-bearing moon Enceladus contain hydrogen from hydrothermal vents, an environment that some scientists believe led to the rise of life on Earth, research publish”If correct, this observation has fundamental implications for the possibility of life on Enceladus,” geochemist Jeffrey Seewald, of the Woods Hole Oceanographic Institution in Massachusetts, wrote in a related commentary in Science.

The discovery was made using NASA’s Cassini spacecraft, which in September will end a 13-year mission exploring Saturn and its entourage of 62 known moons.

The detection of molecular hydrogen occurred in October 2015 during Cassini’s last pass through Enceladus’ plumes, when it skimmed 30 miles (49 km) above the moon’s southern pole taking samples.

In 2005, Cassini discovered Enceladus’s geysers, which shoot hundreds of miles into space. Some of the material falls back onto the surface as a fresh coat of ice, while much of the rest gathers into a halo of ice dust that feeds one of Saturn’s rings.ed on Thursday showed.

The discovery makes Enceladus the only place beyond Earth where scientists have found direct evidence of a possible energy source for life, according to the findings in the journal Science.

Similar conditions, in which hot rocks meet ocean water, may have been the cradle for the appearance of microbial life on Earth more than 4 billion years ago.

“If correct, this observation has fundamental implications for the possibility of life on Enceladus,” geochemist Jeffrey Seewald, of the Woods Hole Oceanographic Institution in Massachusetts, wrote in a related commentary in Science.

The discovery was made using NASA’s Cassini spacecraft, which in September will end a 13-year mission exploring Saturn and its entourage of 62 known moons.

The detection of molecular hydrogen occurred in October 2015 during Cassini’s last pass through Enceladus’ plumes, when it skimmed 30 miles (49 km) above the moon’s southern pole taking samples.

In 2005, Cassini discovered Enceladus’s geysers, which shoot hundreds of miles into space. Some of the material falls back onto the surface as a fresh coat of ice, while much of the rest gathers into a halo of ice dust that feeds one of Saturn’s rings.

A decade later, scientists measuring the moon’s slightly wobbly orbit around Saturn determined it holds a vast ocean buried 19- to 25 miles (30- to 40 km) beneath its icy shell. The ocean is believed to be the geysers’ source.

Several moons orbiting Jupiter and Saturn are known to contain underground oceans, but Enceladus is the only one where scientists have found proof of an energy source for life.

“We’re moving toward Enceladus’s ocean being habitable, but we’re not making any claims at this point about it being inhabited,” lead author Hunter Waite, with the Southwest Research Institute in San Antonio, Texas, said in an interview.

“The next time we go back … you’re going to take something that not only picks up on the habitability story, but it starts looking for evidence for life.”

Enceladus has a diameter of 310 miles (500 km) and is one of Saturn’s innermost moons. The heat needed to keep its ocean from freezing is thought to come from tidal forces exerted by Saturn and a neighboring larger moon, Dione.

http://www.reuters.com/article/us-space-saturn-moon-idUSKBN17F2DR

by Paul Ratner

An international study claims to have found first observed evidence that our universe is a hologram.

What is the holographic universe idea? It’s not exactly that we are living in some kind of Star Trekky computer simulation. Rather the idea, first proposed in the 1990s by Leonard Susskind and Gerard ‘t Hooft, says that all the information in our 3-dimensional reality may actually be included in the 2-dimensional surface of its boundaries. It’s like watching a 3D show on a 2D television.

“Imagine that everything you see, feel and hear in three dimensions (and your perception of time) in fact emanates from a flat two-dimensional field. The idea is similar to that of ordinary holograms where a three-dimensional image is encoded in a two-dimensional surface, such as in the hologram on a credit card. However, this time, the entire universe is encoded,“ explained the study’s co-author Professor Kostas Skenderis of Mathematical Sciences at the University of Southampton.

The new study involved a team of theoretical physicists and astrophysicists from the U.K., Canada and Italy who studied the cosmic microwave background and discovered enough irregularities there that pointed to the holographic theory as a legitimate rival to the theory of cosmic inflation, the way these anomalies are usually explained.

The new analysis by the scientists was made possible by the advancement of telescope and sensing tech that can look for information in the “white noise” or microwaves that remain from the early universe right after the Big Bang.

By studying and mapping data from the Planck space telescope, the team found that the observational data they found was largely predictable by the math of holographic theory.

“Holography is a huge leap forward in the way we think about the structure and creation of the universe. Einstein’s theory of general relativity explains almost everything large scale in the universe very well, but starts to unravel when examining its origins and mechanisms at quantum level. Scientists have been working for decades to combine Einstein’s theory of gravity and quantum theory. Some believe the concept of a holographic universe has the potential to reconcile the two. I hope our research takes us another step towards this,” added Professor Skenderis.


A sketch of the timeline of the holographic Universe where time runs from left to right. The holographic phase (far left) is where the image is blurry because space and time haven’t been defined yet. After this phase comes to a close, the Universe goes into a geometric phase, which can be described by Einstein’s equations. Credit: Paul McFadden

The implications of this study could lead the scientists to improved understanding of how time and space were created.

“When we go into this concept of holography, it’s a new way of thinking about things. Even the scientists who worked on this for the past 20 years don’t have the right tools or the right language to describe what’s going on,” said Skenderis. “It’s a new paradigm for a physical reality.”

The study’s lead author, Niayesh Afshordi of the Perimeter Institute and the University of Waterlo, expressed a similarly positive sentiment about their finding:

“I would argue this is the simplest theory of the early universe. And so far, this is as simple as it gets. And it could help explain everything we see,” Afshordi said.

You can read the paper by the researchers, from the University of Southampton (UK), University of Waterloo (Canada), Perimeter Institute (Canada), INFN, Lecce (Italy) and the University of Salento (Italy) here in the journal Physical Review Letters: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.041301

http://bigthink.com/paul-ratner/scientists-find-first-observed-evidence-that-our-universe-may-be-a-hologram

A new deep-space study by NASA shows the vast void beyond our home is dotted not only with countless galaxies and stars, but also a stunning number of supermassive black holes.

Using data collected over 80 days of observations by NASA’s Chandra X-ray Observatory spacecraft, the agency released an image that shows the largest concentration of black holes ever seen. According to scientists, the density as viewed from Earth would be equivalent to about 5,000 objects that would fit into the area of the sky covered by the full moon.

“With this one amazing picture, we can explore the earliest days of black holes in the Universe and see how they change over billions of years,” study leader Niel Brandt of Pennsylvania State University in University Park, said in a statement.

The image above shows black holes emitting x-ray energy at a variety of intensities. Red indicates low energy, medium is green, and the highest-energy x-rays observed by Chandra are blue. About 70 percent of the objects in the image are supermassive black holes, with masses estimated to range anywhere from 100,000 to 10 billion times the mass of our sun. Many date back billions of years, forming just after the Big Bang.

While invisible to the naked eye, black holes emit x-rays due to captured matter heating up as it spins faster and faster towards the object’s all-consuming center or event horizon.

http://www.mnn.com/earth-matters/space/blogs/deep-space-photo-reveals-thousands-supermassive-black-holes

by Paul Ratner

If you had enough of the often-depressing world events and the seemingly unresolvable conflicts they engender, you might want to head for space and join the first-ever “nation state in space” that’s been announced by a team of scientists and legal experts. It’s called Asgardia and anyone can become its citizen.

As the site for the project explains (http://asgardia.space/concept), Asgardia is a name that comes from Norse mythology, where Asgard was the name of a city in the sky. In the Marvel universe, Asgardia was built was Tony Stark and ruled by the All-Mother (since Odin was in exile).

Asgardia is the brain-child of the accomplished Russian scientist and businessman Igor Ashurbeyli, who describes the motivation behind this endeavor as an attempt to create a nation founded on “Peace in Space, and the prevention of Earth’s conflicts being transferred into space.” The idea is to create a “mirror of humanity in space” in low-Earth orbit that would be devoid of Earthly divisions based on borders and religions. As Ashurbeyli says: “In Asgardia we are all just Earthlings!”

Besides avoiding Earth-linked divisions, another key goal for the nation would be to protect Earth from space threats, like comets, asteroids, debris, cosmic radiation and infection by extraterrestrial microorganisms.

To make this space nation a reality, Ashurbeyli wants it to achieve recognition from the United Nations, aiming to have a million people sign up to become the new country’s citizens via their website. The initial citizens are likely to be those who work in the space industry already, but anyone can join. The initial goal for the founders was to get 100,000 citizens to sign up, but the number of interested people hit 300K in less than a week and is going up rapidly.

The next step for Asgardia – launching its first satellite in 2017. This will become its first outpost in space, while its citizens will still be Earth-bound. A space station would eventually follow.

As Igor Ashurbeyli explained to the Guardian:

“Physically the citizens of that nation state will be on Earth; they will be living in different countries on Earth, so they will be a citizen of their own country and at the same time they will be citizens of Asgardia.”

The new country will be democratic but not ruled by Earthly laws or the existing space laws. Its founders envision the need for a new “‘Universal space law’ and ‘astropolitics’.

“The existing state agencies represent interests of their own countries and there are not so many countries in the world that have those space agencies,” elaborated Ashurbeyli. “The ultimate aim is to create a legal platform to ensure protection of planet Earth and to provide access to space technologies for those who do not have that access at the moment.”

Whether this effort succeeds, especially in light of the existing space treaty, is of course open to debate, while legal minds are not dismissing it outright.

The Asgardia team’s legal expert Ram Jakhu, the director of McGill University’s Institute of Air and Space Law in Montreal, told Space.com their plan is for Asgardia to have the minimum number of citizens, a government, and an inhabited spacecraft that would be its territory. This would hit 3 of the 4 criteria by the U.N. to become a nation state. The last hurdle is recognition by other U.N. members.

To learn more about Asgardia, to sign up as one of its first citizens, or to come up with the new space nation’s flag and anthem, head here: http://asgardia.space/

http://bigthink.com/paul-ratner/scientists-create-asgardia-the-first-ever-nation-in-space-and-you-can-join?utm_source=Big+Think+Weekly+Newsletter+Subscribers&utm_campaign=4767e83d52-Newsletter_10192016&utm_medium=email&utm_term=0_6d098f42ff-4767e83d52-41106061

By James Griffiths

Astronomers engaged in the search for extraterrestrial intelligence (SETI) are training their instruments on a star around 94 light years from Earth after a very strong signal was detected by a Russian telescope.

An international team of researchers is now examining the radio signal and its star, HD 164595 — described in a paper by Italian astronomer Claudio Maccone and others as a “strong candidate for SETI” — in the hopes of determining its origin.

“The signal from HD 164595 is intriguing, because it comes from the vicinity of a sun-like star, and if it’s artificial, its strength is great enough that it was clearly made by a civilization with capabilities beyond those of humankind,” astronomer Douglas Vakoch, president of METI International, which searches for life beyond Earth, tells CNN.

Whenever a strong signal is detected, “it’s a good possibility for some nearby civilization to be detected,” Maccone tells CNN.

Paul Gilster of the Tau Zero Foundation, which conducts interstellar research, said that if the signal was artificial, its strength suggested it would have to come from a civilization more advanced than our own.

Such a civilization would likely be Type II on the Kardashev scale, an attempt by the Soviet astronomer of the same name to categorize various technological stages of civilizations.

“The Kardashev scale is based basically on the energy that that civilization might be able to funnel for its own use,” says Maccone.

At present, our own species is somewhere near Type I on the scale, whereby a civilization is able to harness all the energy available to it on its own planet, including solar, wind, earthquakes, and other fuels.

A Type II civilization would be able to harness the entirety of the energy emitted by its star, billions of billions of watts.

Doing so would require a colossal undertaking, likely the construction of some kind of superstructure, such as a giant sphere or swarm of super-advanced solar panels popularized by astronomer Freeman Dyson that could catch and store all radiation put out by the sun.

Scientists believe superstructures are probably our best chance of detecting alien life unless they are actively trying to communicate with us.

A Dyson sphere was one of the solutions suggested to the peculiar light fluctuations detected around Tabby’s Star, which caused great excitement when they were detected last year.

Maccone is working on developing an alternative mathematical measure of how advanced civilizations are, based on the amount of knowledge and information available to them, that “might help us in the future classify alien civilizations” that we detect.

What’s happening at HD 164595?

In a statement, Seth Shostak, a senior astronomer with the SETI Institute, said that “it’s hard to understand why anyone would want to target our solar system with a strong signal.”

“This star system is so far away they won’t have yet picked up on any TV or radar that would tell them that we’re here,” he added.

METI International will be observing the star from the Boquete Optical SETI Observatory in Panama, Vakoch says, “searching for any brief laser pulses that might be sent as a beacon from advanced extraterrestrials.”

He stressed the importance of all of the SETI community following up on a signal detected by any single member.

“Without corroboration from an independent observatory, a putative signal from extraterrestrials doesn’t have a lot of credibility.”

The SETI Institute is also examining HD 164595, using the Allen Telescope Array in California.

So far, the team has not found any signals to match those originally detected by the Russian telescope, but Shostak notes that “we have not yet covered the full range of frequencies in which the signal could be located.”

“A detection, of course, would immediately spur the SETI and radio astronomy communities to do more follow-up observations.”

According to Vakoch, “if this were really a signal from extraterrestrials, we’d want to survey the target star across as much of the electromagnetic spectrum as we could.”

So is it aliens?

Probably not, says Vakoch, pointing to potential technological interference or amplification through gravitational lensing, where a signal behind a planet or other large object appears to be far stronger than it actually is, as potential causes.

Maccone says gravitational lensing is “an important possibility that should be taken into account for future SETI research.”

“We should learn how to discriminate that against real extraterrestrial signals,” he added.

Vakoch says “the greatest limitation of the May 2015 signal is that it hasn’t been replicated. Before we can give any credence to a signal as coming from extraterrestrials, we need to see it repeatedly to make sure it wasn’t just a transient phenomenon.”

“It deserves at least a few hours of observing time by SETI researchers at other locations to make sure we don’t miss an opportunity to make first contact, however remote.”

If it does prove to be transient and unexplained, HD 164595 could become another “Wow! signal,” frustratingly tantalizing and mysterious in equal measures.

Shostak writes that “of course (it’s) possible” the signal could be from an extraterrestrial civilization, but without confirmation, “we can only say that it’s ‘interesting’.”

http://www.cnn.com/2016/08/30/health/seti-signal-hd-164595-alien-civilization/index.html

By Aviva Rutkin

Nicknamed Earth’s evil twin, Venus seems like everything our planet is not: scorching hot, dried out and covered in toxic clouds.

But a mere one or two billion years ago, these two wayward siblings might have been more alike. New computer simulations suggest that early Venus might have looked a lot like our home planet – and it might even have been habitable.

“It’s one of the big mysteries about Venus. How did it get so different from Earth when it seems likely to have started so similarly?” says David Grinspoon at the Planetary Science Institute in Tucson, Arizona. “The question becomes richer when you consider astrobiology, the possibility that Venus and Earth were very similar during the time of the origin of life on Earth.”

Grinspoon and his colleagues aren’t the first to imagine that Venus was once hospitable. It’s similar to Earth in size and density, and the fact that the two planets formed so close together suggests that they’re made of the same bulk materials. Venus also has an unusually high ratio of deuterium to hydrogen atoms, a sign that it once housed a substantial amount of water, mysteriously lost over time.

Venus, but snowy
To simulate early Venus, the researchers turned to a model of environmental conditions often used to study climate change here on Earth. They created four versions for Venus, each varying slightly in details such as the amount of energy the planet received from the sun, or the length of a Venusian day. Where information was scant about Venus’s climate, the team filled in educated guesses. They also added a shallow ocean, 10 per cent the volume of Earth’s ocean, covering about 60 per cent of the planet’s surface.

Looking at how each version might have evolved over time, the researchers say they were encouraged to believe that the planet might have looked much like an early Earth, and remained habitable for a substantial portion of its lifetime. The most promising of the four Venuses enjoyed moderate temperatures, thick cloud cover and even the occasional light snowfall.

Could life have emerged on this early Venus? If it did, it’s certainly no more, thanks to the oceans later boiling away and volcanoes drastically reshaping the landscape around 715 million years ago. But the team is not ruling it out.

“There’s great uncertainties in understanding Earth, not only its climate history but the history of how life began,” says Michael Way at the NASA Goddard Institute for Space Studies in New York City. If it began in oceans on Earth – a theory we’ve yet to confirm – the same could be true on a waterlogged Venus. “There’s no reason that life on this world would not have existed in these oceans. But that’s about all you can say.”

Alternative histories
“Both planets probably enjoyed warm liquid water oceans in contact with rock and with organic molecules undergoing chemical evolution in those oceans,” says Grinspoon. “As far as we understand at present, those are the requirements for the origin of life.”

To bolster their findings, the team suggests a future mission to Venus should look out for signs of water-related erosion near the equator, which would provide evidence for the oceans detailed in their simulation. Such signs have already been detected by missions at Mars. NASA is currently weighing up two potential Venus projects, although neither has been confirmed. One mission would drop a probe through the clouds down to the surface, while another would orbit around the planet and image its surface.

The researchers would also like to run simulations of further alternative pasts for Venus – perhaps one where it was a desert world, or submerged in as much water as Earth, to find out which scenario is most likely to lead to the Venus we see today.

The study could also aid astronomers in their search for exoplanets, says James Kasting at Pennsylvania State University. If Venus might have once been habitable, then it suggests that other planets close to their stars might be, too. “If you make the habitable zone really wide, that raises the probability of finding an Earth.”

Reference: arxiv.org/abs/1608.00706

https://www.newscientist.com/article/2100191-venus-could-have-been-habitable-while-life-evolved-on-earth/

by Robby Berman

All the scientific studies in the world of this one mysterious star have so far ruled out every theory except one, and it’s the wildest one. The whole thing started when Yale astronomer Tabetha Boyajian located star KIC 8462852, unofficially known as “Tabby’s star,” after Boyajian. Tabby’s star is doing something very strange.

In 2009, NASA launched its Kepler probe to keep a close watch on a small section of the sky — the idea was to learn more about a smaller area than less about a larger one. The probe tracks how light reflected from stars dims and grows brighter. Generally, when a star dims, a planet has passed in front of it, and will again and again as it travels its orbital path.

Kepler’s found some 2,000+ planets orbiting stars and published its data to allow citizen scientists to confirm their findings. A group of people affiliated with Yale called Planet Finders started going over the data, and Boyajian found her star.

To start with, it’s unexpectedly dim for a star of its its size and age. But what really got her attention was this chart.

Each vertical dip represents a holy-cow reduction in the star’s brightness, more than 10 times the dimming that astronomers would expect from a planet even as big as Jupiter crossing in front of the star. So it appears it’s not a planet causing Tabby’s star to dim, which is why it’s also called the “WTF star,” after the paper they published about it titled “Where’s the Flux?”

The data suggests something huge is orbiting the star, but what?

The reason the WTF star is famous is the hypothesis put forward to explain the dimming by Penn State astronomer Jason Wright: That what’s orbiting the star could be a “swarm of megastructures,” alien-built energy collectors, much like terrestrial solar panels. Wright told The Atlantic, “When Boyajian showed me the data, I was fascinated by how crazy it looked. Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build.” He was imagining something like a Dyson sphere.

Crazy, right? Well, since then scientists have been frantically pushing out other hypotheses to explain the anomaly.

Here are some of the more normal theories, and why they’re probably wrong:
•Kepler was malfunctioning — Nope.
•It’s a cloud of dust from star formation — But the star isn’t young. It shows no sign of the infrared light that indicates a new star.
•It’s a swarm of comets — But the dimming is too extreme to be caused by comets.
•It’s debris from colliding planets — But that matter would get sucked into the star so quickly it would be unlikely to linger long enough for us to see it.

http://bigthink.com/robby-berman/science-keeps-not-debunking-the-alien-dyson-sphere-idea?utm_source=Big+Think+Weekly+Newsletter+Subscribers&utm_campaign=344e51650c-Newsletter_081716&utm_medium=email&utm_term=0_6d098f42ff-344e51650c-41106061