Tag: space

A Boeing CST-100 crew capsule approaches the International Space Station carrying a new crew for NASA in this artist’s illustration. NASA has awarded Being its first order for a commercial crew flight in 2017. Credit: Boeing

NASA has awarded Boeing with the first order for a commercial crew change flight to the International Space Station once the company’s new CST-100 space taxi is ready for manned flights in 2017.

Both Boeing and SpaceX are building private spaceships to ferry astronauts on round trips to the space station for NASA. While SpaceX has not received an order yet, NASA said the company will likely receive one later this year. Who flies first will be determined at a later date.

“Final development and certification are top priority for NASA and our commercial providers, but having an eye on the future is equally important to the commercial crew and station programs,” said Kathy Lueders, manager of NASA’s commercial crew program, in a statement. “Our strategy will result in safe, reliable and cost-effective crew missions.” [Boeing’s CST-100 Space Capsule in Pictures] 

The milestone follows on from Boeing successfully finishing the fourth stage in its Commercial Crew Transportation Capability (CCtCap) contract with NASA. Boeing showed the agency that its spacecraft design was ready for assembly, integration and testing.

“We’re on track to fly in 2017, and this critical milestone moves us another step closer in fully maturing the CST-100 design,” said John Mulholland, Boeing’s vice president of commercial programs, in a statement.

For its part, SpaceX successfully launched an unpiloted pad abort test earlier this month.

NASA makes its orders for CCtCap two or three years before the mission takes place, to give time for the companies to build the spacecraft. That said, Boeing (and SpaceX, when its mission is awarded) will need to fully finish its certification before being allowed to fly the astronauts.

Once the crew launches are running, a standard mission will see four crew members on board that are either from NASA or sponsored by NASA. The mission profile calls for the spacecraft to carry 220 pounds of pressurized cargo and to remain docked to the station for up to 210 days.

NASA added that the 2017 flight date depends on Congress awarding the agency’s full budget request for the 2016 fiscal year, and the ones following.

Follow Elizabeth Howell @howellspace, or Space.com @Spacedotcom. We’re also on Facebook and Google+. Original article on Space.com.

The Earth’s precession is captured in stunning detail in this image by a veteran astrophotographer.

In an email to Space.com, night sky photographer Miguel Claro said he developed a new photo technique  showing a Vega “polar” star trail. The image was taken from inside the Mourão Castle, in the Dark Sky Alqueva Reserve, the First Starlight Tourism Destination in the world, in Alentejo, Portugal.

Earth’s axis changes over time due to a phenomenon called “precession,” which pulls the direction of the axis in a circle that takes 26,000 years to trace out in the sky. What this means is the direction of north changes in the sky over time. A consequence of the precession is a changing pole star. Typically, Polaris is used to mark a position but Claro says he was fascinated with the possibility of using a different star. But because of Earth’s precession, the star Vega will likely serve as a new North Star in the year 14,000, even though it never comes closer than 5 degrees to the celestial pole, Claro wrote. [The Brightest Stars in the Night Sky]

 But what would that look like to future astrophotographers?

In a post on his website, Claro explains how he used two star-tracker mountings to help create the views of both Polaris and Vega serving as the North Star in the image above. He also posted a video of the skywatching feat on Vimeo.

Claro used a Canon EOS 6D – Canon EF 8-15 f/ 4L Fisheye USM at 8mm (All Sky) at exposure 30 seconds and ISO 2500 to create the images.

To see more amazing night sky photos submitted by Space.com readers, visit our astrophotography archive.

Editor’s note: If you have an amazing night sky photo you’d like to share for a possible story or image gallery, please contact managing editor Tariq Malik at spacephotos@space.com.

Follow Space.com on Twitter @Spacedotcom. We’re also on Facebook & Google+. Origina l article on Space.com.

Volunteers at Peterson Air Force Base take calls from children wanting to know where Santa is. Credit: U.S. Navy

North American Aerospace Defense Command (NORAD) is a military organization that is shared between the United States and Canada. The group is tasked with looking for threats or activity in aerospace, which can include anything from looking for aircraft, spacecraft or missiles. As of 2006, a renewal of the agreement added maritime activities.

The commander for NORAD is based at Peterson Air Force Base in Colorado and is expected to update both the U.S. president and the Canadian prime minister if required. NORAD’s work is also split between three regions: Alaska (at Elmendorf Air Force Base), Canada (Winnipeg, Manitoba) and continental (Tyndall Air Force Base in Florida).

In addition to its military work, NORAD is also known for tracking Santa every Christmas Eve. 

Early history

Around the same time that the United States and Russia were jockeying for positions in space, military concerns were changing the nature of defense back on Earth. When the Cold War began in the 1940s, Americans were concerned about the potential of long-range Soviet bombers, who may be able to cross an ocean without anyone in the United States knowing about it, according to NORAD.

The United States created an Air Defense Command in 1948, and in 1954 decided to add the Navy and Army to it as well. Dubbed Continental Air Defense Command (CONAD), the organization implemented an advance warning system including radar, and came up with the plans to deploy troops should an invasion occur.

Canada and the United States share a long border, so over time officials believed it made sense to share resources. This led to the creation of NORAD in 1958. Meanwhile, as the USSR improved its missile capabilities in the 1960s, NORAD took over an Air Force warning system to track the missiles worldwide by satellite.

“Throughout the 1970s, the ballistic missile threat caused policy makers to reassess the effectiveness of the air defense system,” NORAD wrote. 

“This meant the potential demise of the arguments for enhanced traditional air defense, and moved NORAD to focus on such challenges as improved warning of missile and space attack, defense against the ICBM [intercontinental ballistic missile], and greater protection and survival of command, control and communication networks and centers.”

Moving to modern days

Some structural changes came to NORAD in the late 1970s, such as changing the A to represent “Aerospace” rather than “Air” in its acronym. This was intended to represent its mandate to track satellites and space launches around the world.

Other structural changes included updating the early-warning system, and altering the command structure for ballistic missile warning and space surveillance.

NORAD also participated in campaigns such as tracking drug traffickers in the 1980s, after the Cold War finished. While its mandate to look for airborne threats continued, its work altered after the terrorist attacks of Sept. 11, 2001, in New York City. It now does regular air patrols under the name Operation Noble Eagle.

The organization has also had a few false alarms over the years. For example: on Nov. 9, 1979, according to History.com, NORAD officials received word that the Soviets were about to send missiles toward North America. 

After sending orders to interceptor aircraft and moving to protect the U.S. president, NORAD realized its mistake: a technician had accidentally loaded a training program for a Soviet attack. There were three unrelated computer problems for NORAD in the following year.

Tracking Santa

For the past six decades, NORAD has also taken on a special non-military role – it tracks down the whereabouts of the jolly old man in red.

It began Dec. 24, 1955, when the Continental Air Defense Command (CONAD) Operations Center in Colorado Springs, Colo., received a call from a young girl tracking down Santa Claus’ whereabouts. Several other calls followed, the result of a misprint in a local newspaper advertisement.

Colonel Harry Shoup, who was on duty, decided to take on the job and asked his colleagues to find where Santa was. CONAD continued the tradition every Christmas. When NORAD was created in 1958, the organization inherited the duty.

To this day, on Christmas Eve, NORAD provides updates on social media, on a website and through the telephone so children know Santa’s whereabouts.

Additional resources

A new view of Ceres, captured by NASA’s Dawn probe on May 23, 2015, shows fine details of the dwarf planet’s surface coming into focus. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

A new photo from NASA’s Dawn spacecraft shows the battered surface of the dwarf planet Ceres in unprecedented detail.

Dawn captured the image on May 23, when the probe was just 3,200 miles (5,100 kilometers) from Ceres. The photo’s resolution is about 1,600 feet (480 meters) per pixel, scientists said.

“The view shows numerous secondary craters, formed by the re-impact of debris strewn from larger impact sites. Smaller surface details like this are becoming visible with increasing clarity as Dawn spirals lower in its campaign to map Ceres,” NASA officials wrote in an image description today (May 28).

“The region shown here is located between 13 degrees and 51 degrees north latitude and 182 degrees and 228 degrees east longitude,” they added. “The image has been projected onto a globe of Ceres, which accounts for the small notch of black at upper right.”

NASA’s Dawn spacecraft captured this image of the dwarf planet Ceres’ heavily cratered surface on May 23, 2015, from a distance of 3,200 miles (5,100 kilometers).
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The $473 million Dawn mission launched in September 2007 to study Vesta and Ceres, the two largest objects in the main asteroid belt between Mars and Jupiter. Vesta and Ceres are planetary building blocks left over from the solar system’s early days, so Dawn’s observations should help researchers better understand how rocky worlds like Earth and Mars formed and grew, NASA officials have said.

Dawn orbited the 330-mile-wide (530 km) Vesta from July 2011 through September 2012 and reached Ceres, which is 590 miles (950 km) across, this March. In the process, Dawn became the first spacecraft to orbit two objects beyond the Earth-moon system, as well as the first to circle a dwarf planet.

Dawn is studying Ceres from a series of progressively closer-in orbits. The craft’s first science orbit lay about 8,400 miles (13,500 km) from the dwarf planet’s surface; Dawn is currently spiraling down to a 2,700-mile-high (4,400 km) orbit, which it should reach on June 3.

By the time Dawn wraps up its mission in June 2016, it will be eyeing Ceres’ intriguing surface from just 230 miles (375 km) away.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

This “remastered” view of Europa is based on information from NASA’s Galileo mission of the 1990s. The 2014 view more closely resembles how the moon of Jupiter would look like to the human eye. Credit: NASA/JPL-Caltech/SETI Institute

NASA’s Europa spacecraft will use nine scientific instruments to assess the icy, ocean-harboring Jupiter moon’s ability to support life, space agency officials announced today (May 26).

The Europa probe — which is scheduled to launch in the early to mid-2020s — will carry supersharp cameras, a heat detector, ice-penetrating radar and a variety of other gear that will shed light on the satellite’s surface composition and the nature of its salty subsurface sea, among other things, NASA officials said.

The newly announced scientific payload “will help us take great strides forward in understanding the habitability of Europa,” Curt Niebur, Europa program scientist at NASA’s Washington headquarters, said during a news conference today. [Europa May Harbor Simple Life-Forms (Video)] 

Haven for life?

Astrobiologists regard the 1,900-mile-wide (3,100 kilometers) Europa as one of the solar system’s best bets to host extraterrestrial life.

Europa possesses a salty ocean beneath its ice shell, and this sea is apparently in contact with the moon’s rocky mantle, making possible a number of complex chemical reactions, scientists say. In addition, scientists think that Europa’s seafloor also features hydrothermal vents, providing a potential energy source for life-forms, if any exist in the dark depths. (Life thrives at Earth’s undersea vents, and some researchers think these environments gave rise to the planet’s first organisms.)

Most of what scientists know about Europa is based on data gathered by NASA’s Galileo mission, which orbited Jupiter in the 1990s and early 2000s and made about a dozen flybys of Europa during that time.

The new mission, which will cost roughly $2 billion, aims to build upon and increase that knowledge significantly, specifically investigating the icy world’s life-hosting potential. The current plan calls for sending a solar-powered spacecraft into orbit around Jupiter; from there, the probe would make about 45 flybys of Europa over the course of two and a half years or so.  

“We find that multiple flybys can allow us to get a complete picture of Europa,” said Jim Green, head of NASA’s Planetary Science division.

In July 2014, NASA asked researchers around the world to propose scientific instruments for the Europa mission. The space agency received 33 submissions and has now selected nine to go on the spacecraft, Niebur said today. [Europa and Its Ocean (Video)]

An artist’s illustration shows a concept for a future NASA mission to Europa, Jupiter’s moon.
Credit: NASA/JPL-Caltech

Taking Europa’s measure

The Europa flyby probe’s imaging system will consist of one wide-angle camera and one narrow-angle one, Niebur said. These two cameras will map almost 90 percent of Europa’s surface down to a resolution of 164 feet (50 meters), and will image parts of the moon 100 times more sharply than that.

Galileo, by contrast, imaged just 10 percent of Europa’s surface down to a resolution of 650 feet (200 m), Niebur said.

“If we’ve seen such amazing things on only 10 percent of the surface, it’s hard to even imagine the amazing things we’ll see when we look at the rest of Europa at even better resolution,” Niebur said.

Two other instruments — a magnetometer and a magnetic sounder — will work together to determine the thickness of Europa’s ice shell and the depth and salinity of its ocean. The ice-penetrating radar equipment will provide even more detail about the moon’s icy crust.

The probe will also carry a heat detector to pinpoint active sites on Europa — for example, places where plumes of water vapor may be erupting into space.

NASA’s Hubble Space Telescope spotted signs of such geysers erupting in 2012, but further searches have not yet confirmed their existence. The Europa spacecraft will carry a plume-hunting spectrograph, to both find and chacterize these elusive features.

Furthermore, an infrared spectrometer will allow the probe to map out the composition of Europa’s surface. Scientists are especially keen to know exactly what makes up the reddish-brown “gunk” that coats large fractures on the moon, since the stuff likely erupts onto the surface from the ocean below.

“If we can determine what that brown gunk is, we can then understand what is in the water — what is in the oceans of Europa — and that is an incredibly important question to answer if we’re trying to figure out if this place is habitable,” Niebur said.

The final two instruments — a mass spectrometer and a dust analyzer — will characterize gases and small solid particles that get blasted off Europa’s surface into space, allowing mission scientists to study the moon’s surface composition without touching down. 

No life-detection gear

The Europa flyby mission is dedicated to probing the moon’s habitability, not actively seeking out signs of life.

“Building a life detecor is incredibly difficult,” Niebur said. “We’re not even sure how to go about building it yet. But it’s something that has received renewed interest and vigor lately because of the Europa mission, so that’s something that we’re going to be poking into a lot more aggressively in the near future.”

Many astrobiologists would love to get a probe down on Europa’s surface — and, ideally, into the underground ocean. The data gathered by the flyby spacecraft could help pave the way for such an ambitious effort, NASA officials said.

“It’d be great to think that the results from this particular mission would lead, in the next decade, to some new and exciting concepts about potentially getting underneath the ice shell,” Green said.

More information is needed to determine if Europa “can be penetrated in a way to be able to get under the ice shell,” he added. “But that’s, indeed, in the distant future.”

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

Editor’s Update for 11:30 am ET: The Air Force’s X-37B space plane has successfully launched on its fourth mission. Read our latest story: US Air Force Launches X-37B Space Plane on 4th Mystery Mission

The United States Air Force’s X-37B space plane and a tiny solar-sailing spacecraft will launch into orbit today, and you can watch the liftoff live.

The unmanned X-37B spacecraft is scheduled to blast off atop a United Launch Alliance Atlas V rocket today (May 20) from Florida’s Cape Canaveral Air Force Station, during a four-hour launch window that opens at 10:45 a.m. EDT (1445 GMT).

You can watch the launch webcast live via United Launch Alliance, or via Space.com partner Spaceflight,Now. Coverage begins at 10:45 a.m. EDT (1445 GMT), with the launch window extending through 2:45 p.m. EDT (1845 GMT). Space.com will carry Spaceflight Now’s launch feed here.

The U.S. Air Force’s fourth X-37 space plane mystery mission will launch into space atop an Atlas V rocket on May 20, 2015 from Cape Canaveral Air Force Station. It is the fourth secret mission for the classified military space plane program.
Credit: United Launch Alliance

The Atlas V is also carrying 10 tiny “cubesats” to orbit, including one called LightSail, which was developed by the nonprofit Planetary Society. LightSail aims to test key technologies ahead of a more involved solar-sailing mission using another cubesat in Earth orbit next year.

Today’s launch marks the fourth space mission — known as Orbital Test Vehicle 4 (OTV-4) — for the reusable X-37B space plane, which looks a bit like NASA’s now-retired space shuttle. The X-37B is much smaller, however; two of these robotic space planes could fit inside the shuttle’s payload bay.

Details about the X-37B’s activities are classified, as are most of its payloads, so it’s unclear what the space plane will be doing on orbit or how long it will be aloft. But Air Force officials have long maintained that the vehicle is not a space weapon, stressing that it simply tests technologies for reusable spacecraft and future missions.

The Air Force owns two X-37B vehicles, both of which were built by Boeing’s Phantom Works division. The two space planes had combined to fly three missions before today. Those prior flights launched in April 2010, March 2011 and December 2012, and lasted for 225, 469 and 675 days, respectively. 

LightSail, meanwhile, is scheduled to deploy its 344-square-foot (32 square meters) sail 28 days from now. Atmospheric drag will pull the cubesat back down to Earth two to 10 days after this occurs, Planetary Society representatives say, but the brief mission should show how well LightSail’s attitude-control and sail-deployment systems work.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

An artist’s depiction of the Fermi Gamma-ray Space Telescope (FGST) in orbit. Credit: NASA

A clue to one of the biggest questions in cosmology — why regular matter, rather than antimatter, survived to fill the universe — may have been found in data from a NASA space telescope.

A new study suggests that gamma-rays (high-energy light) detected by the Fermi Gamma-ray Space Telescope show signs of the existence of a magnetic field that originated mere nanoseconds after the Big Bang. In addition, the researchers on the new study speculate that the magnetic field carries evidence of the fact that there is far more matter than antimatter in our universe.

The detection of the signal in the Fermi data is currently too weak to be claimed as a “discovery,” and no other solid evidence of an early-universe magnetic field exists. But if the signal bears out and the researchers’ speculations withstand scrutiny, the work could help scientists understand why the observable universe is made primarily of matter and not antimatter. [The Gamma Ray Universe: Photos by the Fermi Telescope]

Matter vs. antimatter

It’s easy to take matter for granted. The stuff that makes up our planet and everything on it — as well as our sun and all the other visible objects in the universe — never seems to be at risk of disappearing in an instant. But around the time our universe was born, there may have been just such an instant — a moment when matter won out and something called antimatter did not.

Cosmologists think the universe started with equal parts matter and antimatter; when matter and antimatter collide with great force, they annihilate each other. So, what happened to most of the antimatter (it still exists in the universe, but in very small quantities)? Why did matter dominate? It’s one of the biggest questions plaguing modern science.

Tanmay Vachaspati, a professor of physics at Arizona State University and his colleagues think they have found a clue to this mystery. They say that a signal in the Fermi gamma-ray data suggests an overwhelming production of matter, but not antimatter, in the early universe. They detailed their findings in a paper published online today (May 14) in the journal Monthly Notices of the Royal Astronomical Society.

A universal magnetic field

The team claims to have identified a sort of “twisting” of the gamma rays that the Fermi telescope detects, and the researchers say the detection of this twisted gamma-ray signal is verified in their paper.

Vachaspati and his colleagues’ interpretation of what that signal means boils down to this: The twisted gamma-rays are evidence of a magnetic field that has been present in the universe since less than a second after the Big Bang. This magnetic field has a left-hand orientation, and that is evidence of the overwhelming production of matter in the early universe, as antimatter would have produced a right-hand orientation, they said. [Most Amazing Gamma Ray Sources in the Universe]

There are many particle-physics events that must occur for this magnetic field to leave an imprint on the gamma-rays, the researchers .

Scientists don’t know for sure if this kind of “primordial” magnetic field exists in our universe. There have been magnetic fields observed in some galaxies and galaxy clusters that could be magnifications of a magnetic field that already existed in the universe, and to demonstrate that it exists would be a fascinating discovery, scientists say.

The discovery of this left-hand signal was first reported by Vachaspati and colleagues in a paper published in 2014.

“We were kind of cautious, and we didn’t want to make a big deal of it, because we thought maybe the signal would go away with more data or more analysis,” Vachaspati said. “And then, in [the new paper], we used more data and did other kinds of analysis. And the signal is still there.”

But the signal may not be a “discovery” quite yet.

In analyzing statistical data from instruments like the Fermi telescope, there is always a chance that a signal could arise purely by chance. The odds of this occurring are measured by a value called sigma. A result with 1 sigma has roughly 1-in-3 odds of arising purely by chance (not a very good bet).

The signal detected by Vachaspati and colleagues has a 3-sigma uncertainty, or about 0.3 percent odds that it has appeared purely by chance. This may seem good, but in particle physics, most signals are not officially called a “discovery” until they have a 5-sigma value (1-in-2-million chance that the signal is a purely random fluctuation).

Tonia Venters, a researcher at NASA Goddard Space Flight Center who works with Fermi telescope data, said it’s important to practice caution.

“Our field has seen many results at [2- and 3-sigma] significances come and go, so we tend to be rather skeptical when faced with even a 3-sigma result (0.3% probability of occurring by chance),” Venters told Space.com in an email. “To us, a 3-sigma result is interesting enough to wait for more data, but not enough to generate much excitement.”

It should be noted that there are other ways to judge the validity of a signal, and sigma is not always the best metric to use. However, it often serves as a good way to quickly evaluate the strength of a result. Vachaspati said he puts more weight on the fact that certain predictions made about the signal in the first paper were confirmed in the new analysis.

The next step, Vachaspati said, is to continue to look for the signal in more Fermi telescope data. The collaboration is expected to release new data this year. He will discuss the work with colleagues from around the world at a monthlong conference on cosmological magnetic fields this June and July.

“I think the most important part is that we’re seeing a suspicious signal in the data, and then the rest is kind of one step at a time,” Vachaspati said. “We think the most likely candidate for why this is happening is the magnetic field. And then, if it is the magnetic field, then it seems most likely to me it’s going to be this matter-antimatter asymmetry.

“But people have different ideas, so that part becomes more theoretical,” he added. “The interesting thing is that there seems to be a signal.”

Follow Calla Cofield @callacofield.Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

This image shows a rare view of four quasars, indicated by white arrows, found together by astronomers using the Keck Observatory in Hawaii. The bright galactic nuclei are embedded in a giant nebula of cool, dense gas visible in the image as a blue haze. Credit: Hennawi & Arrigoni-Battaia, MPIA

A giant nebula in the early universe hits the jackpot when it comes to rare, bright objects known as quasars, boasting four within surprisingly close proximity to one another. The first known quasar quartet lies in a cloud of cool gas that could provide a clue to the objects’ unusual closeness.

“Multiple-quasar systems are rare, because quasars themselves are rare,” Joseph Hennawi, of the Max Planck Institute for Astronomy in Germany, told Space.com by email.

“The typical distance between any two quasars is about 100 million light-years, whereas we found four quasars within 700,000 light-years of each other,” he said. “The … probability of that occurring is extremely small — about 1 in 10 million odds.” [The Strangest Things in Space]

Quadruple quasar

The center of every galaxy boasts a supermassive black hole millions of times the mass of the sun. Material swirling around the rim of the black hole travels near the speed of light, emitting an enormous amount of energy before it is consumed. If the supply is large enough, it enters the quasar phase of its evolution, far outshining its parent galaxy to become one of the brightest objects in the universe.

But the lives of quasars are extremely brief; according to Hennawi, a quasar shines somewhere between 10 million to 100 million years in the 10-billion-year lifetime of a galaxy. This makes the objects extremely rare and hard to find. Discovering four so close together came as something of a shock.

Hennawi and his colleagues were studying 29 quasars in search of a nebula of cool hydrogen gas, known as Lyman-α (Lyman-alpha) nebulae, surrounding them. The bright light of a quasar can illuminate the gas around it, helping astronomers to better understand the properties of the gas.

Selecting one likely candidate, the team trained a Keck telescope in Hawaii on the object, and found one of the largest and brightest Lyman-α nebulae yet discovered. Inside the cloud of gas, the researchers identified not one but four tightly packed quasars, all lying surprisingly close together.

Nearly 500,000 quasars have been identified so far, but scientists know of only about a hundred binary quasars. Two triple quasar systems have been found since 2007. This, however, is the first known quadruple-quasar system.

The research is published online today (May 14) in the journal Science.

Hitting the ‘Jackpot Nebula’

While it is possible that the researchers simply lucked out — indeed, they dubbed the cool dense cloud of gas the “Jackpot Nebula” — Hennawi said it is more likely that the discovery reveals more about how quasars might form.

“The primary significance of the quadruple-quasar system is the extremely low probability of a discovery like this occurring by chance, according to our current understanding of the abundance of quasars,” Hennawi said.

“We thus either have to conclude that we got really lucky — 1 in 10 million [odds] — or that quasar activity is much more likely to occur in certain environments. That, in turn, could be an important piece of the puzzle for understanding what makes a galaxy turn on as a quasar.”

The nebula that’s home to the four quasars sits within a protocluster, a forerunner of a galaxy cluster like those that exist today. The light took about 10 billion years to reach scientists today, so they are seeing the protocluster as it existed in the early universe (which is only about 13.7 billion years old).

The protocluster itself is somewhat unusual, containing up to 20 times more galaxies than other already-dense objects of the same type. It also contains a giant nebula of cool gas that Hennawi said is at odds with current theories of how protoclusters should form. These unusual clouds, which have been seen in other protoclusters, may have something to do with the formation of the quadruple-quasar system.

The quartet itself is one of the few quasar systems to reside in a protocluster; a handful of rare quasars and at least one known typical quasars can also be found in protoclusters and are almost always associated with Lyman-α clouds of gas.

“We speculate that the likelihood of quasar activity may be highly enhanced in this object because of the massive amount of cool, dense gas, which would be related to fueling the quasars,” Hennawi said.

Although the quadruple quasar sits in a dense group of galaxies, Hennawi says that there is no sign that previously discovered multi-quasar systems lie in extreme environments. However, the environments of these systems have not been characterized that well. Of the handful of giant nebulae found around quasars, several are related to multiple-quasar systems.

“We were searching for giant nebulae associated with massive amounts of cool gas, and then basically stumbled upon this quadruple quasar,” Hennawi said. “Since discovering a quadruple quasar is so unlikely, we conclude that giant nebulae of cool gas, protoclusters and quasar activity are all interrelated somehow.”

He said that the next step is to try to find more of these giant emission clouds by searching for them around individual quasars, something that the new results suggest is easier than previously thought.

“One important result of our study is that we showed that about 10 percent of all the bright quasars in the distant universe have these giant nebulae around them,” Hennawi said.

“If we go out and find a sample of 10 to 20 giant nebulae, we can determine how often they are associated with multiple quasars [and] how often they trace protoclusters, and [we can] also study other properties.”

Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

The Andromeda Galaxy, shown here, may be much larger than astronomers previously thought. Astrophotographer Lorenzo Comolli took this photo Nov. 16, 2012, from Bogli, Italy. Credit: Lorenzo Comolli

One of the Milky Way’s closest galactic neighbors is surrounded by a much bigger halo of gas than previously thought, new observations from the Hubble Space Telescope reveal.

The halo of the Andromeda Galaxy — the nearest spiral galaxy to the Milky Way — is about six times larger and 1,000 times more massive than measured before, the new observations show. It is so large that if the halo were visible from Earth, it would be 100 times the diameter of the full moon — or about the size of two basketballs held at arm’s length.

“Halos are the gaseous atmospheres of galaxies,” said lead researcher Nicholas Lehner, a physicist at the University of Notre Dame, in Indiana, in a statement from NASA. “The properties of these gaseous halos control the rate at which stars form in galaxies, according to models of galaxy formation.” [Amazing Photos of the Andromeda Galaxy]

A halo of gas surrounds the Andromeda galaxy, new observations show, giving the galaxy a diameter of roughly 2 million miles.
Credit: NASA

Scientists spotted the dark halo by looking at bright objects that are behind the gas and seeing how the light changes. Specifically, they used quasars, or galaxies with huge black holes at their cores that are extremely bright despite being far away.

As the light leaves the quasar, some of the gas in the halo absorbs the light and makes the quasar appear darker. This is most apparent when it is observed in ultraviolet light (short wavelengths of light). Measuring the dip in brightness allows astronomers to figure out the amount of gas in front of the quasar.

Because ultraviolet light is absorbed by Earth’s atmosphere, the Hubble telescope was ideally placed to see the changes in brightness because it orbits above the planet.

A previous program by Hubble, called the Hubble Cosmic Origins Spectrograph (COS)-Halos program, observed 44 galaxies far away and saw halos. Andromeda, however, is the first close-up galaxy where a halo has been observed.

The authors of the new research say large-scale simulations of galaxies suggest the halo is the same age as the rest of Andromeda, which lies 2.5 million light-years away from Earth. Additionally, the halo is full of elements that are heavier than hydrogen and helium. This indicates at least some of the gas comes from supernovas, explosions of old stars that fused hydrogen and helium into heavier elements through their lifetimes.

As for our own galaxy — the Milky Way — it’s possible that it also hosts a halo, but that it’s invisible from Earth. “It’s a case of not being able to see the forest for the trees,” the NASA statement said.. If our galaxy does have a halo, it’s possible that it is starting to merge with that of Andromeda’s. Our two galaxies are expected to merge into one galaxy starting in roughly 4 billion years.

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