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NSF/LIGO/Sonoma State University/A. Simonnet
NSF/LIGO/Sonoma State University/A. Simonnet

Astronomers Observe a New Kind of Massive Cosmic Collision for the First Time

NSF/LIGO/Sonoma State University/A. Simonnet
NSF/LIGO/Sonoma State University/A. Simonnet

For the first time, astronomers have detected the colossal blast produced by the merger of two neutron stars—and they've recorded it both via the gravitational waves the event produced, as well as the flash of light it emitted.

Physicists believe that the pair of neutron stars—ultra-dense stars formed when a massive star collapses, following a supernova explosion—had been locked in a death spiral just before their final collision and merger. As they spiraled inward, a burst of gravitational waves was released; when they finally smashed together, high-energy electromagnetic radiation known as gamma rays were emitted. In the days that followed, electromagnetic radiation at many other wavelengths—X-rays, ultraviolet, optical, infrared, and radio waves—were released. (Imagine all the instruments in an orchestra, from the lowest bassoons to the highest piccolos, playing a short, loud note all at once.)

This is the first time such a collision has been observed, as well as the first time that both kinds of observations—gravitational waves and electromagnetic radiation—have been recorded from the same event, a feat that required co-operation among some 70 different observatories around the world, including ground-based observatories, orbiting telescopes, the U.S. LIGO (Laser Interferometer Gravitational-Wave Observatory), and European Virgo gravitational wave detectors.

"For me, it feels like the dawning of a next era in astrophysics," Julie McEnery, project scientist for NASA's Fermi Gamma-ray Space Telescope, one of the first instruments to record the burst of energy from the cosmic collision, tells Mental Floss. "With this observation, we've connected these new gravitational wave observations to the rest of the observations that we've been doing in astrophysics for a very long time."

A BREAKTHROUGH ON SEVERAL FRONTS

The observations represent a breakthrough on several fronts. Until now, the only events detected via gravitational waves have been mergers of black holes; with these new results, it seems likely that gravitational wave technology—which is still in its infancy—will open many new phenomena to scientific scrutiny. At the same time, very little was known about the physics of neutron stars—especially their violent, final moments—until now. The observations are also shedding new light on the origin of gamma-ray bursts (GRBs)—extremely energetic explosions seen in distant galaxies. As well, the research may offer clues as to how the heavier elements, such as gold, platinum, and uranium, formed.

Astronomers around the world are thrilled by the latest findings, as today's flurry of excitement attests. The LIGO-Virgo results are being published today in the journal Physical Review Letters; further articles are due to be published in other journals, including Nature and Science, in the weeks ahead. Scientists also described the findings today at press briefings hosted by the National Science Foundation (the agency that funds LIGO) in Washington, and at the headquarters of the European Southern Observatory in Garching, Germany.

(Rumors of the breakthrough had been swirling for weeks; in August, astronomer J. Craig Wheeler of the University of Texas at Austin tweeted, "New LIGO. Source with optical counterpart. Blow your sox off!" He and another scientist who tweeted have since apologized for doing so prematurely, but this morning, minutes after the news officially broke, Wheeler tweeted, "Socks off!") 

The neutron star merger happened in a galaxy known as NGC 4993, located some 130 million light years from our own Milky Way, in the direction of the southern constellation Hydra.

Gravitational wave astronomy is barely a year and a half old. The first detection of gravitational waves—physicists describe them as ripples in space-time—came in fall 2015, when the signal from a pair of merging black holes was recorded by the LIGO detectors. The discovery was announced in February 2016 to great fanfare, and was honored with this year's Nobel Prize in Physics. Virgo, a European gravitational wave detector, went online in 2007 and was upgraded last year; together, they allow astronomers to accurately pin down the location of gravitational wave sources for the first time. The addition of Virgo also allows for a greater sensitivity than LIGO could achieve on its own.

LIGO previously recorded four different instances of colliding black holes—objects with masses between seven times the mass of the Sun and a bit less than 40 times the mass of the Sun. This new signal was weaker than that produced by the black holes, but also lasted longer, persisting for about 100 seconds; the data suggested the objects were too small to be black holes, but instead were neutron stars, with masses of about 1.1 and 1.6 times the Sun's mass. (In spite of their heft, neutron stars are tiny, with diameters of only a dozen or so miles.) Another key difference is that while black hole collisions can be detected only via gravitational waves—black holes are black, after all—neutron star collisions can actually be seen.

"EXACTLY WHAT WE'D HOPE TO SEE"

When the gravitational wave signal was recorded, on the morning of August 17, observatories around the world were notified and began scanning the sky in search of an optical counterpart. Even before the LIGO bulletin went out, however, the orbiting Fermi telescope, which can receive high-energy gamma rays from all directions in the sky at once, had caught something, receiving a signal less than two seconds after the gravitational wave signal tripped the LIGO detectors. This was presumed to be a gamma-ray burst, an explosion of gamma rays seen in deep space. Astronomers had recorded such bursts sporadically since the 1960s; however, their physical cause was never certain. Merging neutron stars had been a suggested culprit for at least some of these explosions.

"This is exactly what we'd hoped to see," says McEnery. "A gamma ray burst requires a colossal release of energy, and one of the hypotheses for what powers at least some of them—the ones that have durations of less than two seconds—was the merger of two neutron stars … We had hoped that we would see a gamma ray burst and a gravitational wave signal together, so it's fantastic to finally actually do this."

With preliminary data from LIGO and Virgo, combined with the Fermi data, scientists could tell with reasonable precision what direction in the sky the signal had come from—and dozens of telescopes at observatories around the world, including the U.S. Gemini telescopes, the European Very Large Telescope, and the Hubble Space Telescope, were quickly re-aimed toward Hydra, in the direction of reported signal.

The telescopes at the Las Campanas Observatory in Chile were well-placed for getting a first look—because the bulletin arrived in the morning, however, they had to wait until the sun dropped below the horizon.

"We had about eight to 10 hours, until sunset in Chile, to prepare for this," Maria Drout, an astronomer at the Carnegie Observatories in in Pasadena, California, which runs the Las Campanas telescopes, tells Mental Floss. She was connected by Skype to the astronomers in the control rooms of three different telescopes at Las Campanas, as they prepared to train their telescopes at the target region. "Usually you prepare a month in advance for an observing run on these telescopes, but this was all happening in a few hours," Drout says. She and her colleagues prepared a target list of about 100 galaxies, but less than one-tenth of the way through the list, by luck, they found it: a tiny blip of light in NGC 4993 that wasn't visible on archival images of the same galaxy. (It was the 1-meter Swope telescope that snagged the first images.)

A NEW ERA OF ASTROPHYSICS

When a new star-like object in a distant galaxy is spotted, a typical first guess is that it's a supernova (an exploding star). But this new object was changing very rapidly, growing 100 times dimmer over just a few days while also quickly becoming redder—which supernovae don't do, explains Drout, who is cross-appointed at the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto. "We ended up following it for three weeks or so, and by the end, it was very clear that this [neutron star merger] was what we were looking at," she says.

The researchers say they can't be sure if the resulting object was another, larger neutron star, or whether it would have been so massive that it would have collapsed into a black hole.

As exciting as the original detection of gravitational waves last year was, Drout is looking forward to a new era in which both gravitational waves and traditional telescopes can be used to study the same objects. "We can learn a lot more about these types of extreme systems that exist in the universe, by coupling the two together," she says.

The detection shows that "gravitational wave science is moving from being a physics experiment to being a tool for astronomers," Marcia Rieke, an astronomer at the University of Arizona who is not involved in the current research, tells Mental Floss. "So I think it's a pretty big deal."

Physicists are also learning something new about the origin of the heaviest elements in the periodic table. For many years, these were thought to arise from supernova explosions, but spectroscopic data from the newly observed neutron star merger (in which light is broken up into its component colors) suggests that such explosion produce enormous quantities of heavy elements—including enough gold to put Fort Knox to shame. (The blast is believed to have created some 200 Earth-masses of gold, the scientists say.) "It's telling us that most of the gold that we know about is produced in these mergers, and not in supernovae," McEnery says.

Editor's note: This post has been updated.

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Space
Linguists Say We Might Be Able to Communicate With Aliens If We Ever Encounter Them
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iStock

If humans ever encountered extraterrestrials, would we be able to communicate with them? That was the question posed by linguists from across the country, including famed scholar Noam Chomsky, during a workshop held in Los Angeles on May 26.

Organized by a scientific nonprofit called Messaging Extraterrestrial Intelligence (METI), the one-day event entitled "Language in the Cosmos" brought together two camps that don't usually converge: linguists and space scientists. The event was held in conjunction with the National Space Society's annual International Space Development Conference, which featured the likes of theoretical physicist Freeman Dyson, Amazon CEO and Blue Origin founder Jeff Bezos, SpaceX's Tom Mueller, science fiction writer David Brin, and more.

Linguist Sheri Wells-Jensen, chair of the workshop, said in a statement that it's unlikely we'll ever come face to face with aliens or find ourselves in a "Star Trek universe where most of the aliens are humanoid and lots of them already have a 'universal translator.'" Still, scientists don't rule out the possibility of chatting with extraterrestrials via radio.

Chomsky, who's often regarded as the father of modern linguistics, was optimistic that extraterrestrial life forms—if they're out there—might observe the same “universal grammar” rules he believes serve as the foundation for all human languages. His theory of universal grammar posits that there's a genetic component to language, and the ability to acquire and comprehend language is innate. Chomsky argues that a random mutation caused early humans to make the “evolutionary jump” to language some 40,000 years ago through a process called Merge, which lets words be combined, according to New Scientist. (Not all linguists are convinced by Chomsky's theory.)

At the workshop, a presentation by Chomsky (of MIT), Ian Roberts (University of Cambridge), and Jeffrey Watumull (Oceanit) argued that "the overwhelming likelihood is that ET Universal Grammar would be also be based on Merge." They said grammar would probably not be the greatest barrier in communicating with aliens; rather, understanding their "externalization system," or whatever channel they're using to communicate, could be the greatest challenge.

Another presentation by Jeffrey Punske (Southern Illinois University) and Bridget Samuels (University of Southern California) drew a similar conclusion. Human languages have physical and biological constraints, some of which are grounded in physics, so it follows that extraterrestrial languages would be limited by the same laws of physics, the linguists said.

Douglas Vakoch, president of METI, said in a statement that these theories represent a "radical shift" for scientists working in the field, who have "scoffed at the idea of creating interstellar messages inspired by natural languages." Past radio messages sent out into space relied on math and science, in hopes that those principles are universal.

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Space
The 12 Men Who Walked on the Moon
NASA / Harrison H. Schmitt
NASA / Harrison H. Schmitt

If you were born after the Apollo program, and maybe even if you remember those days, it seems almost unbelievable that NASA sent manned missions to the moon 239,000 miles away. People continue to express sadness at the fact that the Apollo lunar missions were so long ago, and that soon there will be no one left alive who actually went to the moon. Today, Alan Bean—the fourth man to walk on the moon and the last surviving member of the Apollo 12 mission—passed away at the age of 86. Which makes it the perfect time to remember—or get to know—the only 12 people who ever walked on a body other than planet Earth.

1. NEIL ALDEN ARMSTRONG

Navy test pilot, engineer, and Korean War veteran Neil Armstrong left the Navy in 1952, but continued in the Naval Reserve. He worked as an experimental test pilot for the National Advisory Committee for Aeronautics (NACA) beginning in 1955, which evolved into NASA. Armstrong was assigned as an astronaut in 1962, and flew on the Gemini 8 mission in 1966, where he performed the first successful space docking procedure. Armstrong was selected to be the first man to walk on the moon, as the Apollo 11 mission was planned, for several reasons: he was the commander of the mission, he didn't have a big ego, and the door of the lunar lander was on his side. Although the first steps on the moon are what he will always be known for, Armstrong considered the mission's biggest accomplishment was landing the lunar module. He later said,

Pilots take no special joy in walking: pilots like flying. Pilots generally take pride in a good landing, not in getting out of the vehicle.

Armstrong along with his crew were honored with parades, awards, and acclaim after their return to Earth, but Armstrong always gave credit to the entire NASA team for the Apollo moon missions. He resigned from NASA in 1971 and became a professor of of Aerospace Engineering at the University of Cincinnati for eight years. Armstrong served on the boards of many corporations and foundations, but gradually withdrew from publicity tours and autograph signings. He didn't particularly care for fame.

Neil Armstrong died on August 25, 2012, at age 82. His family released a statement that concluded:

“For those who may ask what they can do to honor Neil, we have a simple request. Honor his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink.”

2. EDWIN "BUZZ" ALDRIN

After graduating third in his class at West Point in 1951 with a degree in science, Buzz Aldrin flew 66 combat missions as an Air Force pilot in the Korean War. Then he earned a PhD at MIT. Aldrin joined NASA as an astronaut in 1963. In 1966 he flew in the Gemini 12 spacecraft on the final Gemini mission.

Aldrin accompanied Neil Armstrong on the first moon landing in the Apollo 11 mission, becoming the second person, and now the first of the living astronauts, to set foot on the moon. Aldrin had taken a home Communion kit with him, and took Communion on the lunar surface, but did not broadcast the fact. Aldrin retired from NASA in 1971 and from the Air Force in 1972. He later suffered from clinical depression and wrote about the experience, but recovered with treatment. Aldrin has co-authored five books about his experiences and the space program, plus two novels. Aldrin, who is now 88 years old, continues to work to promote space exploration.

3. CHARLES "PETE" CONRAD

Pete Conrad was a Princeton graduate and Navy test pilot before entering the astronaut corps in 1962. He flew on the Gemini V mission and was commander of Gemini XI. Conrad was commander of the Apollo 12 mission, launched during a lightning storm which temporarily knocked out the command module's power shortly after liftoff. When Conrad stepped onto the moon, he said,

Whoopee! Man, that may have been a small one for Neil, but that's a long one for me.

Conrad later flew on the Skylab 2 mission as commander with the first crew to board the space station. He retired from NASA and the Navy in 1973, after which he worked for American Television and Communications Company and then for McDonnell Douglas.

Pete Conrad died on July 8, 1999 in a motorcycle accident. He was 69.

4. ALAN L. BEAN

Apollo astronaut Alan Bean was the fourth man to walk on the moon, during the Apollo 12 mission in 1969. He was the lunar module pilot. Bean was also the commander of the Skylab Mission II in 1973, which spent 59 days in flight. Altogether, Bean logged 1,671 hours and 45 minutes in space. Bean is the only artist to have visited another world, so his paintings of the lunar environment have the authenticity of an eyewitness. He retired from the Navy with the rank of Captain, but continued to train astronauts at NASA until 1981, when he retired to devote time to his art.

Bean died on May 26, 2018 at the age of 86.

5. ALAN SHEPARD

Alan Shepard was a bona-fide space pioneer who cemented his spot in history long before the Apollo program. A U.S. Navy test pilot, he was selected as one of the original Mercury astronauts in 1959. Shepard was the first American launched into space aboard the Freedom 7 spacecraft on May 5, 1961. His suborbital flight reached an altitude of 116 miles.

Barred from flight during the Gemini program because of an inner ear problem, Shepard had the problem fixed surgically and was assigned as commander of the Apollo 14 mission to the moon. He was responsible for the most accurate lunar module landing ever, and spent 9 hours and 17 minutes exploring the moon's surface outside the module. During that time, he famously knocked a couple of golf balls with a six-iron attached to his sample-collecting tool. With one arm (due to the space suit), he managed to drive further than professional golfers on Earth could ever hope to, thanks to the moon's lower gravity.

Before and after his Apollo mission, Shepard served as Chief of the Astronaut Office. He retired from NASA and the Navy in 1974, having achieved the rank of Rear Admiral. Shepard went into private business, serving on the board of several corporations and foundations. He founded Seven Fourteen Enterprises, an umbrella corporation named after his two space missions. Shepard wrote a book with Deke Slayton, Moon Shot: The Inside Story of America's Race to the Moon. Shepard compared his book to The Right Stuff by Tom Wolfe, saying, "'We wanted to call ours 'The Real Stuff,' since his was just fiction.''

Alan Shepard died on July 21, 1998 at the age of 74.

6. EDGAR D. MITCHELL

Ed Mitchell joined the Navy in 1952 and became a test pilot. Then he earned a PhD in Aeronautics and Astronautics from MIT. NASA selected him for the astronaut corps in 1966. In January of 1971, Mitchell flew on Apollo 14 as lunar module pilot, becoming the sixth man to walk on the lunar surface. He retired in 1972 and founded the Institute of Noetic Sciences, which explores psychic and paranormal events. Mitchell gained some notoriety after NASA for his views on UFOs, as he has asserted that the government is covering up evidence at Roswell. His information, he admitted, came secondhand from various sources.

Mitchell died on February 4, 2016, the eve of the 45th anniversary of his lunar landing.

7. DAVID RANDOLPH SCOTT

David Scott joined the Air Force after graduating from West Point. Selected as an astronaut in 1963, he flew with Neil Armstrong on the Gemini 8 mission and was command module pilot on Apollo 9. Scott then went to the moon on Apollo 15, which landed on the lunar surface on July 30, 1971. It was the first mission to land near mountains. Scott and Jim Irwin spent 18 hours exploring the lunar landscape in the Lunar Roving Vehicle in the first mission to use such a vehicle to travel on the moon.

Scott became famous for the "postage stamp incident," in which he took unauthorized postage stamp covers to the moon with the intent to sell them afterwards. NASA had turned a blind eye to such activities before, but publicity over the matter caused them to discipline Scott and he never flew again. Scott retired from NASA in 1977 and served as a consultant for several movies and TV shows about the space program. He also wrote a book with former cosmonaut Alexei Leonov, Two Sides of the Moon: Our Story of the Cold War Space Race.

David Scott is 85 years old.

8. JAMES B. IRWIN

Air Force test pilot James Irwin became an astronaut in 1966. He was the lunar module pilot for Apollo 15 in 1971. His 18.5 hours of lunar surface exploration included gathering many samples of rocks. The astronauts' medical conditions were being monitored from Earth, and they noticed Irwin developing symptoms of heart trouble. As he was breathing 100% oxygen and under lower gravity than on Earth, mission control decided he was in the best environment possible for such irregularity -under the circumstances. Irwin's heart rhythm was normal by the time Apollo 15 returned to Earth, but he had a heart attack a few months later. Irwin retired from NASA and the Air Force (with the rank of Colonel) in 1972 and founded the High Flight Foundation in order to spread the Christian gospel during the last twenty years of his life. He notably took several groups on expeditions to Mt. Ararat to search for Noah's Ark.

James Irwin died on August 8, 1991, of a heart attack. He was 61 years old.

9. JOHN WATTS YOUNG

John Young is so far the longest serving astronaut in NASA history. He was selected as an astronaut in 1962 and his first space flight was in 1965 aboard Gemini 3 with Gus Grissom. He achieved some notoriety at that time by smuggling a corned beef sandwich onto the flight, angering NASA. But Young went on to complete a total of six space missions in the Gemini, Apollo, and the space shuttle programs. He orbited the moon on the Apollo 10 mission, then was commander of the Apollo 16 mission and became the ninth person to walk on the moon. Young was also commander of the first space shuttle flight in 1981 and returned for shuttle flight 9 in 1983, which deployed the first Spacelab module. Young was also scheduled for another space shuttle flight in 1986, which was delayed after the Challenger disaster, so the veteran astronaut never made his seventh flight. Young finally retired from NASA after 42 years of service in 2004.

John Young died on January 5, 2018 at the age of 87 following complications with pneumonia.

10. CHARLES M. DUKE JR.

Astronaut Charles Duke was capcom during the Apollo 11 mission. His is the voice you recall saying, "Roger, Twank... Tranquility, we copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again. Thanks a lot!" when the lunar module landed on the moon. Duke also made history by catching German measles while training in the backup crew for the Apollo 13 mission, exposing the crew to the disease and causing Ken Mattingly to be replaced by Jack Swigart on that terrifying spaceflight. Duke went to the moon (with Mattingly as command module pilot) on the Apollo 16 mission in April of 1972. He retired from NASA in 1975 having reached the rank of Brigadier General in the U.S. Air Force, and founded Duke Investments. Duke also became a Christian and a lay minister to prison inmates.

Charles Duke is 82 years old.

11. HARRISON "JACK" SCHMITT

Jack Schmitt was a geologist first, and trained as a pilot only after becoming a NASA astronaut. In fact, he was only the second civilian to fly into space, after Neil Armstrong, who was a veteran at the time of his flights. Schmitt was assigned to fly to the moon on the Apollo 18 mission, but when the Apollo 18 and 19 missions were cancelled in September of 1970, the scientific community lobbied to have Schmitt reassigned to Apollo 17 (replacing Joe Engle) as lunar module pilot. He was the first scientist in outer space. On the Apollo 17 mission, he and Gene Cernan spent three days on the lunar surface (a record) and drove their Lunar Roving Vehicle around collecting samples, conducting experiments, and leaving measuring instruments behind. Schmitt and Cernan gathered 250 pounds of lunar material to take back.

After resigning from NASA in 1975, Schmitt, a Republican, was elected Senator for New Mexico and served from 1977 to 1983. He became an adjunct professor at the University of Wisconsin–Madison, and lives in Silver City, New Mexico. In recent years, Dr. Schmitt's scientific background and political leanings have kept him in the spotlight as he has said that the concept of climate change is "a red herring," and that environmentalism is linked with communism.

Jack Schmitt is 82 years old.

12. EUGENE E. CERNAN

As a Navy pilot, Gene Cernan logged over 5,000 hours flying time. He was accepted into the astronaut program in 1963. Cernan's first space flight was on Gemini IX in 1966, in which he conducted extravehicular activities (a space walk), followed by the Apollo 10 mission in May of 1969, which orbited the moon. Cernan was assigned commander of the Apollo 17 mission before anyone knew it would be the last Apollo mission. Even after the Apollo program was cut, no one knew for sure that travel to the moon would be abandoned for decades. When Schmitt and Cernan boarded their lunar module for the last time on December 13th, 1972, Cernan said:

"I'm on the surface; and, as I take man's last step from the surface, back home for some time to come — but we believe not too long into the future — I'd like to just [say] what I believe history will record. That America's challenge of today has forged man's destiny of tomorrow. And, as we leave the Moon at Taurus-Littrow, we leave as we came and, God willing, as we shall return: with peace and hope for all mankind. Godspeed the crew of Apollo 17."

Cernan retired from the Navy and from NASA in 1976. He went on to found an aerospace technology firm, and wrote a book about his experiences as an astronaut. He also contributed his talents to ABC-TV as a commentator during shuttle flights and has made appearances on various space specials. In September of 2011, Cernan testified before Congress on the future of the space program.

The space program has never been an entitlement, it's an investment in the future - an investment in technology, jobs, international respect and geo-political leadership, and perhaps most importantly in the inspiration and education of our youth. Those best and brightest minds at NASA and throughout the multitudes of private contractors, large and small, did not join the team to design windmills or redesign gas pedals, but to live their dreams of once again taking us where no man has gone before.

Gene Cernan died on January 16, 2017

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