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March 12, 2018

Has the 40-year old mystery of the "Wow!" signal been solved?

One of the most enduring astronomical mysteries may have finally been solved, as researchers find that comets are strong candidates for the famous Wow! signal

In August 1977, the Ohio State University Radio Observatory picked up a radio transmission from the Sagittarius constellation that was so strong it inspired the astronomer who discovered it to write "Wow!" in the margin of the data printout. Almost 40 years later, researchers from the Center for Planetary Science may have finally solved the mystery of the Wow! Signal's origin, and it's bad news for alien hopefuls: it was probably a comet.
At the time the signal was spotted, Ohio State's "Big Ear" observatory was specifically searching for transmissions that could be evidence of extraterrestrial civilizations. Based on the work of earlier astronomers, the team determined that a message of intelligent origin would most likely be transmitted at a frequency of 1,420 MHz – the electromagnetic frequency of hydrogen – and that the Big Ear would "hear" it for 72 seconds, since that's how long the observatory could focus on one specific point in space.
The Wow! signal was the first and only time exactly those criteria were met. Excited scientists tried training instruments on that region of space again, but the signal was never again recorded. Over the years, interference from Earth was ruled out, as were stellar bodies like planets, stars and asteroids. Aliens seemed unlikely, but tantalizingly, couldn't be ruled out.
Last year, a group of researchers from the Center of Planetary Science proposed a new hypothesis that argued a comet might be the culprit. The frequency could be caused by the hydrogen cloud they carry, and the fact that they move accounts for why it seemingly disappeared. Two comets, named 266/P Christensen and P/2008 Y2 (Gibbs), happened to be transiting through that region of space when the Wow! signal was detected, but they weren't discovered until after 2006.
To test the hypothesis, the team made 200 radio spectrum observations between November 2016 and February 2017. Sure enough, 266/P Christensen was found to emit radio waves at a frequency of 1,420 MHz, and to double check, the researchers moved their radio telescope by one degree. As expected, the signal vanished, and only returned when the telescope was trained back on the comet.
And 266/P Christensen wasn't an anomaly: the researchers tested three other comets, P/2013 EW90 (Tenagra), P/2016 J1-A (PANSTARRS), and 237P/LINEAR, and found they all emit signals at the same frequency.
Whether the Wow! signal was caused by 266/P Christensen or another comet, it seems that one of the most enduring astronomical mysteries has been put to rest.
The research was published in the Journal of the Washington Academy of Sciences.

Source: Center for Planetary Science

March 01, 2018

Simulation suggests 68 percent of the universe may not actually exist

by Unknown, in universe

New computer simulations have questioned the existence of dark energy, a so-far theoretical force that is said to be driving the expansion of the universe(Credit: NASA/JPL-Caltech)

According to the Lambda Cold Dark Matter (Lambda-CDM) model, which is the current accepted standard for how the universe began and evolved, the ordinary matter we encounter every day only makes up around five percent of the universe's density, with dark matter comprising 27 percent, and the remaining 68 percent made up of dark energy, a so-far theoretical force driving the expansion of the universe. But a new study has questioned whether dark energy exists at all, citing computer simulations that found that by accounting for the changing structure of the cosmos, the gap in the theory, which dark energy was proposed to fill, vanishes.
Published in 1915, Einstein's general theory of relativity forms the basis for the accepted origin story of the universe, which says that the Big Bang kicked off the expansion of the universe about 13.8 billion years ago. The problem is, the equations at work are incredibly complicated, so physicists tend to simplify parts of them so they're a bit more practical to work with. When models are then built up from these simplified versions, small holes can snowball into huge discrepancies.
"Einstein's equations of general relativity that describe the expansion of the universe are so complex mathematically, that for a hundred years no solutions accounting for the effect of cosmic structures have been found," says Dr László Dobos, co-author of the new paper. "We know from very precise supernova observations that the universe is accelerating, but at the same time we rely on coarse approximations to Einstein's equations which may introduce serious side effects, such as the need for dark energy, in the models designed to fit the observational data."
Dark energy has never been directly observed, and can only be studied through its effects on other objects. Its properties and existence are still purely theoretical, making it a placeholder plug for holes in current models.
The mysterious force was first put forward as a driver of the universe's accelerated expansion in the 1990s, based on the observation of Type Ia supernovae. Sometimes called "standard candles," these bright spots are known to shine at a consistent peak brightness, and by measuring the brightness of that light by the time it reaches Earth, astronomers are able to figure out just how far away the object is.
This research was instrumental in spreading acceptance of the idea that dark energy is accelerating the expansion of the universe, and it earned the scientists involved the Nobel Prize in Physics in 2011. But other studies have questioned the validity of that conclusion, and some researchers are trying to develop a more accurate picture of the cosmos with software that can better handle all the wrinkles of the general theory of relativity.

A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model,... — A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model, including dark energy; middle, in blue, is the new Avera model, which accounts for the structure and doesn't require dark energy; and right, in green, is the original Einstein-de Sitter model, which also doesn't include dark energy(Credit: István Csabai et al)

According to the new study from Eötvös Loránd University in Hungary and the University of Hawaii, the discrepancy that dark energy was "invented" to fill might have arisen from the parts of the theory that were glossed over for the sake of simplicity. The researchers set up a computer simulation of how the universe formed, based on its large-scale structure. That structure apparently takes the form of "foam," where galaxies are found on the thin walls of each bubble, but large pockets in the middle are mostly devoid of both normal and dark matter.
The team simulated how gravity would affect matter in this structure and found that, rather than the universe expanding in a smooth, uniform manner, different parts of it would expand at different rates. Importantly, though, the overall average rate of expansion is still consistent with observations, and points to accelerated expansion. The end result is what the team calls the Avera model.
"The theory of general relativity is fundamental in understanding the way the universe evolves," says Dobos. "We do not question its validity; we question the validity of the approximate solutions. Our findings rely on a mathematical conjecture which permits the differential expansion of space, consistent with general relativity, and they show how the formation of complex structures of matter affects the expansion. These issues were previously swept under the rug but taking them into account can explain the acceleration without the need for dark energy."
If the research stands up to scrutiny, it could change the direction of the study of physics away from chasing the ghost of dark energy.

The research was published in the Monthly Notices of the Royal Astronomical Society, and an animation below compares the different models.

Source: Royal Astronomical Society, NewAtlas

March 01, 2018

Gravitational anomaly from the beginning of the universe observed on Earth

by Unknown, in universe

IBM Researchers have observed a gravitational anomaly in a crystal, which was normally believed to only occur in exotic matter in deep space or just after the Big Bang(Credit: IBM Research)

When the universe was just a few microseconds old, it existed as a strange soupy substance called quark-gluon plasma (QGP), which exhibits a whole host of unusual quantum effects. Now, for the first time, IBM researchers have observed a gravitational anomaly in earthly materials, which was previously only thought to occur in QGP in deep space or just after the Big Bang.
The world of classical physics is governed by the laws of conservation, stating that a measurement like energy or mass in a system cannot change quantity, although it may change form. But exotic types of matter, like QGP, can exhibit quantum effects that throw those laws out the window.
These exotic materials, forged in the crucible of the Big Bang or high energy particle accelerators, were thought to be the only places such quantum phenomena could occur. But now IBM scientists have observed a quantum effect called an axial-gravitational anomaly in recently-discovered materials called Weyl semimetals.
The electrons in these crystals are divided into two groups according to the direction of their spin, and normally there are equal numbers of each type of electron. But when the researchers mimicked a gravitational field by imposing a temperature gradient, they found that quantum anomalies mess with this symmetry by changing electrons from one type to the other, and vice versa. This is the first time that this gravitational anomaly has been observed under normal circumstances here on Earth.

Dr. Karl Landsteiner, co-author of the paper, with a diagram explaining the finding(Credit: IBM Research)

"This is an incredibly exciting discovery," says Karl Landsteiner, co-author of the paper. "We can clearly conclude that the same breaking of symmetry can be observed in any physical system, whether it occurred at the beginning of the universe or is happening today, right here on Earth."
Weyl semimetals are solid state crystals, so to find these anomalies at work inside them has implications for electronics built on solid state physics.
"For the first time, we have experimentally observed this fundamental quantum anomaly on Earth which is extremely important towards our understanding of the universe," says Johannes Gooth, lead author of the paper. "We can now build novel solid-state devices based on this anomaly that have never been considered before to potentially circumvent some of the problems inherent in classical electronic devices, such as transistors."

The research was published in the journal Nature.

Source: IBM [1],[2], NewAtlas

February 27, 2018

Deep space communications goes commercial

by Unknown, in universe

The commercial tracking system will use the GHY-6 antenna at Goonhilly(Credit: GES - Goonhilly Earth Station Ltd)

Commercial spaceflight may bring to mind flashy images of dramatic rocket launches and sleek space capsules, but it also means the infrastructure to support such endeavors. Case in point is a co-operative project between Britain and the European Space Agency to establish the world's first commercial deep-space tracking and communications station in Goonhilly, Cornwall. Using a repurposed 32-m (105-ft) dish built in 1985, it will be able to communicate with spacecraft millions of miles away.

We're seeing a renaissance of space flight with multiple missions to Mars as well as ones to intercept asteroids, comets, and even venturing out into the Kuiper Belt. The trouble is that all these spacecraft require ground stations back on Earth to track and communicate with these far-flung missions and many of these stations, like those of NASA's Deep Space Network, were built in the days of the Space Race in the 1960s.

And while new networks, including ESA's three deep-space dishes in Australia, Spain and Argentina, have alleviated some of the data-link congestion, future missions including private companies seeking to mine the asteroids or colonize the Moon or Mars threaten to quickly overwhelm the system. This is especially true as the Europeans ready to launch their BepiColombo mission to Mercury, along with the Solar Orbiter, Euclid, and Cheops probes.

"The amount of science data flowing in from ESA's current missions, not to mention from future missions with improved instruments, is growing strongly," says ESA's Pier Bargellini, responsible for network operations. By the middle of the next decade, ESA's deep-space communication needs for supporting today's missions, like ExoMars, and upcoming spacecraft, like Juice, is expected to exceed our present capacity by around half. We are considering urgently how to bridge this gap."

The first step in solving this problem is being taken at the famous Goonhilly Earth Station. As Britain's primary telecommunications ground station, Goonhilly was the site of the world's first transatlantic television transmission on July 11, 1962 when a live television signal was transmitted between the United States and Europe via the Telstar satellite.

Today, Goonhilly is a sprawling complex of 140 acres (57 hectares) with 60 radio dishes carrying radio, television, telephone, and internet traffic. One of these dishes, GHY-6, is being upgraded over the next two years to provide tracking and communication links with commercial deep-space missions as part of a €9.5 million (US$12 million) investment from the Cornwall & Isles of Scilly Local Enterprise Partnership, which will be later supplemented by ESA. The first test links will be with ESA mission, including Mars Express.

"Once the station upgrade work is complete, in about 24 months, Goonhilly will be able to complement ESA's own stations, and provide deep-space tracking for the Agency's missions as well as those of other space agencies or from private space start-ups aiming to exploit the Moon or mine asteroids," says Klaus-Jürgen Schulz, who is responsible of ESA ground station engineering.

Source:

ESA, NewAtlas

February 18, 2018

Monster x-ray machine blasts apart black hole theory

by Unknown, in x-ray machine

The Z machine at Sandia National Laboratories creates tremendous bursts of energy using less power than it would take to light 100 homes for a few minutes(Credit: Randy Montoya/Sandia Labs, CC2.0)

There is lightning being made in Albuquerque, New Mexico. But unlike the kind that shoots between sky and earth, this lightning takes place inside the Z machine at Sandia National Laboratories. The lightning made inside this miracle of engineering carries more than 1,000 times the electricity of a regular bolt, and is 20,000 times faster – so fast, in fact, that the pulse released would go as fast as traveling from Los Angeles to New York in slightly less than one second. The machine also produces intense X-rays, and researchers have just used this component of the its ability to shake up a long-held theory regarding black holes.

The Z machine is the world's most powerful source of laboratory radiation. It's used to study how materials act under extreme conditions (it can melt diamonds, for example) as well to conduct fusion experiments and run simulations of what happens during a nuclear explosion. In a recent study though, researchers used the machine to duplicate the X-rays that surround black holes. Such X-rays are emitted from the great dark voids when gas surrounding them in what's known as the accretion disc is heated to incredibly high temperatures before getting sucked in by the hole's gargantuan gravitational force.

Because black holes can't be directly studied due to their confounding habit of devouring everything – including energy – the best we can do is study what's known as X-ray spectra (the wavelengths of energy produced in the X-ray band of the electromagnetic spectrum) in their accretion discs created by the superheated gas known as plasma.
"There's lots of information in spectra. They can have many shapes," said NASA astrophysicist Tim Kallman, a co-author of the study. "Incandescent light bulb spectra are boring, they have peaks in the yellow part of their spectra. The black holes are more interesting, with bumps and wiggles in different parts of the spectra. If you can interpret those bumps and wiggles, you know how much gas, how hot, how ionized and to what extent, and how many different elements are present in the accretion disk."

In their study, the researchers upended a theory about ions in a black hole's accretion discs.
For about 20 years, it has been thought that iron ions were present in these accretion discs even if no spectral lines were visible. The thought was that these ions were sheared off from their atoms thanks to the massive gravitational force and radiation emitted from a black hole. This is different from what an ion would normally do – drop to a lower energy state by emitting photons. So even if astronomers couldn't see the photons from the ions, they believed they were still there.

But in the Sandia study, the researchers submitted a dime-sized piece of silicon to the powerful X-rays from the Z machine. Silicon was chosen for the study as it is one of the most abundant elements in the universe. However, the silicon study revealed that if there were no photons, then there were no ions, a finding that dramatically influences the way we have been measuring black holes for years.
"If we could go to the black hole and take a scoop of the accretion disk and analyze it in the lab, that would be the most useful way to know what the accretion disk is made of," said Sandia researcher and lead author Guillaume Loisel. "But since we cannot do that, we try to provide tested data for astrophysical models."

Those models will now have to change says Loisel, because what's in those theoretical "scoops" is different from what we've believed for about the last two decades — in short, the hypothesized iron ions are simply not there.

"Our research suggests it will be necessary to rework many scientific papers published over the last 20 years," he said. "Our results challenge models used to infer how fast black holes swallow matter from their companion star. We are optimistic that astrophysicists will implement whatever changes are found to be needed."

The team's work has been published in the journal Physical Review Letters.

Source: Sandia National Laboratories, NewAtlas

February 15, 2018

NASA sends piece of Mars back to Mars

by Unknown, in universe

Rohit Bhartia of NASA's Mars 2020 mission holds a slice of a meteorite scientists have determined came from Mars(Credit: NASA/JPL-Caltech)

In the ultimate example of sending coals to Newcastle, NASA is sending a piece of Mars back to the Red Planet on the Mars 2020 rover mission. The space agency's including a meteorite that had its origin on Mars may seem odd, but the purpose is completely practical as the sample will act as a calibration target for one of the mission's main instruments.
Spending all the time, money, and labor needed to send a spacecraft to the surface of Mars is pointless if the instruments included on the lander don't send back an accurate account of what they see. For this reason, each Mars landing mission includes a set of calibration targets that serve the same purpose as a test pattern card does on Earth in making sure video equipment is properly adjusted.
An example of this is on the Curiosity rover, which has a calibration paletteconsisting of a US 1909 penny for adjusting the sharpness of the rover's camera, color chips, a metric standardized bar graphic, and a stair-step pattern for depth calibration. Mars 2020 will carry a similar palette, but it will also include a fragment of the meteor Sayh al Uhaymir 008 (SaU008) for adjusting a high-precision laser on the rover's arm.

Close-up of a slice of a meteorite scientists have determined came from Mars

The laser, called the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC), is designed to illuminate features on rock samples as fine as a human hair and analyze them using Raman and fluorescence spectroscopies. To achieve the necessary precision, NASA engineers want to use a calibration sample that is as near to the Martian rocks as possible, so they reasoned that the best choice would be an actual piece of Mars that was blasted off the planet in an ancient asteroid strike and landed on Earth millions of years ago.
"We're studying things on such a fine scale that slight misalignments, caused by changes in temperature or even the rover settling into sand, can require us to correct our aim," said Luther Beegle of the Jet Propulsion Laboratory in Pasadena, California. "By studying how the instrument sees a fixed target, we can understand how it will see a piece of the Martian surface."
According to NASA, the idea behind SHERLOC is to use the laser to cause carbon-based compounds to fluoresce in a manner similar to that produced by a conventional UV lamp, and then examine the resulting spectrogram for signs of life. The meteor sample will help the instrument to better pick out the texture and organic chemicals found.

A slice of a meteorite scientists have determined came from Mars, placed inside an oxygen plasma...

One of only 200 confirmed Martian meteorites found on Earth, Sayh al Uhaymir 008 was provided by the National History Museum in London and was selected because it not only provides good calibration characteristics, but is also robust enough to survive the journey from Earth to Mars without damage.
However, NASA says that this is not the first bit of Mars that it has sent home. The first was onboard the now inactive Mars Global Surveyor, which carries a chunk of a meteorite known as Zagami, but that is still in orbit around the planet. Meanwhile, another instrument on Mars 2020, the SuperCam, will have its own Martian meteorite calibration target. In addition, the rover will carry samples of materials that could be used in spacesuits and other equipment on future manned Mars expeditions.
"The SHERLOC instrument is a valuable opportunity to prepare for human spaceflight as well as to perform fundamental scientific investigations of the Martian surface," said Marc Fries, a SHERLOC co-investigator. "It gives us a convenient way to test material that will keep future astronauts safe when they get to Mars."

Source: NASA, NewAtlas

February 09, 2018

New Horizons claims record for most distant images in history of space exploration

by Unknown, in universe

False-color images of KBOs 2012 HZ84, taken by the New Horizons spacecraft(Credit:NASA/JHUAPL/SwRI)

NASA's New Horizons spacecraft has returned some magnificent images of the Solar System's outer reaches around Pluto, its primary target. Its latest snaps may not be its most spectacular, but are pioneering in their own way as the farthest images ever snapped away from the Earth.

New Horizons grabbed the below black and white photo as it turned its Long Range Reconnaissance Imager (LORRI) toward a cluster of stars known as the Wishing Well, which are around 1,300 light years away from Earth. The craft itself was zipping through space around 3.79 billion miles from Earth, further away than the Voyager 1 spacecraft when it snapped the iconic Pale Blue Dot image in 1990 at a distance of 3.75 billion miles.

Image of the Wishing Well star cluster, snapped by the New Horizons spacecraft

But this record didn't stand for long. In fact New Horizons broke it again two hours later when LORRI was turned toward Kuiper Belt objects 2012 HZ84 and 2012 HE85, the closest ever images of Kuiper Belt objects. And with the probe continuing to hurtle through space at a speed of 700,000 miles (1.1 million km) per day, it will continue to collect more and more distant views of the universe.

The New Horizons spacecraft is said to be in good condition and is currently hibernating, with mission control planning to awaken it again on June 4 in preparation for a flyby of Kuiper Belt object 2014 MU69 in mid-2019. Continuing with the theme, this will be the most remote flyby in the history of robotic space exploration.

The New Horizons team turned its attention to the Kuiper Belt once its work circling Pluto was complete, specifically targeting 2014 MU69. Observations made by the Hubble Space Telescope and ESA's Gaia missionlast year revealed that the object may be shaped like a stretched out American football or even possibly be two separate bodies, configurations scientists described as "provocative" and a potential "scientific bonanza." All will be revealed in due course.

Source: NASA

February 08, 2018

Hubble spots a strange new type of celestial object

by Unknown, in universe

Astronomers have discovered a brand new type of celestial object: an active binary asteroid, meaning it's made of two rocks orbiting each other while leaving a trail of gas like a comet(Credit: ESA/Hubble, L. Calçada)

Astronomers have discovered a brand new type of object in our solar system: an active binary asteroid. That means the object, named Body 288P, is the first known hybrid of two rare types of asteroid: a binary that's made up of two rocks orbiting each other, and an active asteroid that acts more like a comet, leaving a trail of gas and dust in its wake.
Traditionally, the line between asteroids and comets was fairly clear: asteroids are chunks of rock and metal, while comets are icier, causing them to leave a vapor tail when the Sun heats them up. But the more we study these objects, the more that line blurs. Active asteroids kick up clouds of dust and gas, giving them the appearance of comets, but these are rare, with currently only about 20 known examples. When they orbit within the asteroid belt that lies between Mars and Jupiter, these objects are called main-belt comets.
Body 288P was discovered in 2011, and images captured by the Hubble Telescope back then indicated that it was active. But at that time, the asteroid was too far from Earth to get a good look. In September 2016 the asteroid was on its closest approach to the Sun, and as it passed within 200 million km of Earth, astronomers from the Max Planck Institute used Hubble to peer closer. And that's when it became clear that it was made up of not one, but two separate pieces. That makes 288P the first binary main-belt comet.

These observations revealed some of 288P's many quirks. Most binary asteroids are made up of one larger body with a smaller "moon" orbiting it, but 288P's pieces are roughly the same size, each measuring about 1 km (0.62 mi) wide. And they're much further apart than usual, orbiting each other at a distance of about 100 km (62 mi).
According to the Max Planck astronomers, rapid rotation may have caused 288P to break up in the first place, but the fact that the object is still active suggests that this would be a relatively recent development, occurring around 5,000 years ago. Then, the gases it spews likely drove the two pieces apart to their current distant orbit.
"288P's activity probably played a decisive role in its further evolution," says Jessica Agarwal, main author of the study. "The most probable formation scenario of 288P is a breakup due to fast rotation. After that, the two fragments may have been moved further apart by sublimation torques."
Among the many thousands of pieces of debris floating around out there, Body 288P is a completely unique object. Further study is required to figure out how common binary main-belt comets might be, and what clues they can reveal about the origins of the Solar System.
The research was published in the journal Nature. Check out 288P in action in the video below.

Sources: Hubble Space Telescope, Max Planck Institute, NewAtlas

February 05, 2018

Construction begins on first manned Orion spacecraft

by Unknown, in universe

At the NASA Michoud Assembly Facility in Louisiana, Lockheed Martin technicians have started building the first manned Orion(Credit: NASA)

NASA's first of a new generation of manned deep space exploration craft has begun to take shape at the space agency's Michoud Assembly Facility near New Orleans. This week, Lockheed Martin technicians and engineers welded together the first two components of the Orion crew capsule for Exploration Mission-2 (EM-2), which will carry astronauts beyond low Earth orbit for the first time in almost 50 years.
So far, only one operational Orion capsule reached space when the unmanned Exploration Flight Test-1 (EFT-1) lifted off atop a Delta IV Heavy booster on December 5, 2014. A second, more advanced Orion is currently being prepared for Exploration Mission-1. It's scheduled to fly in 2019 using the Space Launch System (SLS) rocket, but again, without a crew.
Though the EM-2 Orion will be a major step in the American program to establish a Deep Space Gateway station, return to the Moon, and eventually make a manned landing on Mars, it isn't much to look at at the moment. The first construction step involved welding the command capsule's forward bulkhead to the tunnel section, to form the top of the spacecraft. In all, seven large machined aluminum alloy pieces will form the pressure vessel, which is the main hull of the craft.
"Orion has tremendous momentum. We're finishing assembly of the EM-1 Orion spacecraft in Florida, and simultaneously starting production on the first one that will carry crew," says Mike Hawes, Lockheed Martin vice president and program manager for Orion. "This is not only the most advanced spacecraft ever built, its production will be more efficient than any previous capsule. For example, look at the progress we've made on the EM-2 pressure vessel compared to the first one we built. The latest version is 30 percent lighter and has 80 percent fewer parts. That equates to a substantially more cost-effective and capable spacecraft."

Early artist's rendering of the Orion crew capsule in lunar orbit. Work is now underway on the real thing.(Credit: Lockheed Martin Corp. )

Lockheed says that construction will continue through September as the three cone panels, large barrel, and aft bulkhead are added on. It will then be shipped to the Kennedy Space Center for final assembly and testing.
"The EM-1 and EM-2 crew modules are very similar in design, but we've made a lot of improvements since we built EM-1, including processes, scheduling, and supply chain, all contributing to a lower cost and faster manufacturing," says Paul Anderson, director of Orion EM-2 production at Lockheed Martin. "Each of these spacecraft are important, but we realize that the EM-2 capsule is special as it's the first one to carry astronauts back out to the Moon, something we haven't done in a long time. It's something we think about every day."

Source: Lockheed Martin, NewAtlas

January 18, 2018

Dark Energy Survey spots remains of 11 galaxies devoured by the Milky Way

by Unknown, in universe

Data released from the Dark Energy Survey has revealed 11 new stellar streams, the leftovers from smaller galaxies that the Milky Way has collided with and devoured(Credit: Dark Energy Survey)

The first intriguing findings have been released from the Dark Energy Survey, a project that's studying the sky to find clues about the mysterious force that seems to be accelerating the expansion of the universe. And among the data is the discovery of 11 new stellar streams, the remains of smaller galaxies that our own Milky Way has torn to shreds.In the late 1990s, it was discovered that the expansion of the universe is accelerating. That goes against the previous prevailing ideas of Einstein's theory of General Relativity, which stated that expansion should be slowing down thanks to gravity. Physicists coined the term "dark energy" to refer to the unknown force that seems to be driving the acceleration, and apparently contributes more than 68 percent of the total energy in the universe. While there is some argument that dark energy doesn't exist, it is currently the most accepted idea to explain these observations.The Dark Energy Survey (DES) was launched in 2013 to try to learn more about the strange phenomenon, and the results from the first three years of that project were released to the public at the American Astronomical Society meeting last week. That data dump includes hundreds of terabytes of images snapped by the 570-megapixel Dark Energy Camera that cover an eighth of the entire sky through about 40,000 photos, as well as catalogs describing hundreds of millions of stars and galaxies."There are all kinds of discoveries waiting to be found in the data," says Brian Yanny, a data management project scientist on DES. "While DES scientists are focused on using it to learn about dark energy, we wanted to enable astronomers to explore these images in new ways, to improve our understanding of the universe."

One of these new discoveries sheds some light on the violent history of the Milky Way. Galaxies collide fairly regularly, with the larger one usually tearing the smaller one to pieces and absorbing its stars and matter. But some of these stars become locked in orbit around the larger galaxy, forming what's known as a stellar stream.
Normally these stellar streams are hard to spot, since the stars that make them up are very spread out. Just 23 streams have been identified in the past, most of which surround the Milky Way, with a few more around our galactic neighbor, Andromeda. That makes the discovery of 11 more in the space of three years pretty impressive.
"It's exciting that we found so many stellar streams," says Alex Drlica-Wagner, an astrophysicist involved in the project. "We can use these streams to measure the amount, distribution and 'clumpiness' of dark matter in the Milky Way. Studies of stellar streams will help constrain the fundamental properties of dark matter."
Along with helping to pull back the curtain on the mysterious dark matter and dark energy, the study can help astronomers piece together the history of the Milky Way and other galaxies.
The Dark Energy Survey's observations are due to wrap up later this year, but we're likely to be hearing about discoveries pulled from its data for a long time yet.

Sources: University of Chicago, Dark Energy Survey, NewAtlas