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Shadow Of The Moon Crosses Earth During Solar Eclipse

Scientists Detect Gravitational Waves As Black Holes Collide

Far from our galaxy, in the vast darkness of space, two massive black holes merged into a single, larger hole.

And now researchers say they have detected rumblings from that cataclysmic collision as ripples in the very fabric of space-time itself. The discovery comes a century after Albert Einstein first predicted such ripples should exist.

"It's a really big event," says Saul Teukolsky, a theoretical astrophysicist at Cornell University. "This is probably the most exciting episode of my professional career."

Einstein predicted the existence of such ripples, known officially as gravitational waves, in 1916, as part of his general theory of relativity. General relativity re-imagines the gravitational pull between heavy objects like Earth and the sun as a "warping" of space and time. When very heavy objects such as black holes are involved, the theory predicts that gravitational waves will emerge and ripple across the entire universe.

That's the idea. But in practice, seeing such gravitational waves has been nearly impossible. To make detectable waves, massive objects must be moving quickly. Researchers predicted a collision between two black holes would do the trick. But nobody knew how often that might happen.

Nevertheless, scientists built two massive detectors to take a look. Known collectively as the Laser Interferometer Gravity-Wave Observatory (LIGO), the detectors are located in Washington state and Louisiana. They are separated by thousands of miles in order to detect ripples coming in from deep space as they pass through Earth.

Each detector looks like a big L, made up of two tunnels 2.5 miles long. It's designed so that if a gravitational wave passes by, it will stretch space along one direction of the tunnel and squish space along the direction of the other. The stretching and squishing changes the tunnels' lengths by a tiny amount, and that change can be detected by lasers.

Although LIGO was completed in 1999, it took more than a decade for it to see anything. The detectors had to be made incredibly sensitive to pick up the tiny waves. But they were so touchy, they were set off by everything from minute shifts in Earth's core to traffic entering the parking lot. And even after researchers got rid of all the terrestrial jiggles, LIGO still wasn't quite good enough to see gravitational waves.

All that changed after a major upgrade in 2014. Better vibrational isolation and upgrades to lasers and mirrors dramatically boosted the instrument's power.

And the black hole collision was seen almost as soon as the team began observing again in the fall of 2015. On Sept. 14 at 5:51 a.m., the waves passed through both of the detectors.

According to a paper published in the journal Physical Review Letters, the two black holes were each roughly 30 times the mass of the sun. They merged some 1.3 billion light years from Earth. The waves were generated in the final moments before the black holes merged. The signal was brief but definitive.

The measurements are dramatic proof that gravitational waves exist. The signal in the detector matches well with what's predicted by Einstein's original theory, according to Teukolsky, who was briefed on the results. It matches predictions of the ripples produced by two large black holes, in the final moments before they merge, swirling together at an enormous speed.

This is, arguably, the most direct observation of black holes ever made. Because black holes are (as their name implies) "black", they can't be seen with ordinary telescopes. Up until now, their existence has been inferred by looking at the stars and gas swirling around them. This gravitational signal comes directly from the holes, and it is virtually incontrovertible proof that the holes are out there. "If black holes didn't really exist, you couldn't explain these waves," he says.

Other researchers believe that the gravitational waves could tell us even more about our cosmos. "It's like looking at the universe with new eyes — the amount of information that's there is going to be amazing," says Mina Arvanitaki, a theorist at the Perimeter Institute of Physics in Waterloo, Ontario. Arvanitaki will use LIGO's data to probe for undiscovered fundamental particles that might only exist in the warped space around black holes.

Teukolsky says the discovery shows just how extraordinary the natural world can be. "The universe is stranger than any kind of fiction we could imagine," he says. "I mean, it's preposterous." npr

Neil DeGrasse Tyson Gets Into A Rap Battle With B.o.B Over Flat Earth Theory

So, a Twitter spat between astrophysicist Neil deGrasse Tyson and rapper B.o.B over the flat Earth theory has turned into a full-blown rap battle (and it's way better than Drake vs. Meek Mill).

B.o.B, whom you might know from his hits "Airplanes," "Nothin' On You" and "Strange Clouds," kicked things off Monday when he started tweeting about how he believes the Earth is flat. He also tweeted about why he believes NASA is hiding the truth about the edge of the world. And he shared several meaningless diagrams about the planet including one about flight routes.

The rapper fired off more than 50 tweets, saying things like "I'm going up against the greatest liars in history ... you've been tremendously deceived," before Tyson took to Twitter to respond.

In a short series of tweets, Tyson explained why the Earth was round. He tweeted:

"Earth's curve indeed blocks 150 (not 170) ft of Manhattan. But most buildings in midtown are waaay taller than that."

"Polaris is gone by 1.5 deg S. Latitude. You've never been south of Earth's Equator, or if so, you've never looked up."

"Flat Earth is a problem only when people in charge think that way. No law stops you from regressively basking in it."

Tyson's last tweet to B.o.B was, "Duude — to be clear: Being five centuries regressed in your reasoning doesn't mean we all can't still like your music."

So, naturally, B.o.B whipped up a song about the why the Earth is flat, called "Flatline," that expanded on the theory, called out Tyson by name and also name-dropped David Irving, a renowned Holocaust denier.

Here's one line: "Aye, Neil Tyson need to loosen up his vest / They'll probably write that man one hell of a check."

Here's another: "I see only good things on the horizon / That's probably why the horizon is always rising / Indoctrinated in a cult called science / And graduated to a club full of liars." You can read the full lyrics on Gawker.

That was Monday night.

Tuesday afternoon, Tyson dropped his own dis track, called "Flat To Fact,"written and rapped by his nephew, Stephen Tyson. He tweeted: "As an astrophysicist I don't rap, but I know people who do. This one has my back." Here's a sample:

"Very important that I clear this up / You say that Neil's vest is what he needs to loosen up? / The ignorance you're spinning helps to keep people enslaved, I mean mentally."

And Tyson's rap didn't pull any punches:

"All those strange clouds must be messing with your brain."

"I think it's very clear that Bobby didn't read enough / And he's believing all this conspiracy theory stuff." npr

You have to hear it to believe it. 

Hey! Let's Vote On Your Best Suggestions On What To Name 'Planet Nine'

...here are the four of the best suggestions:

— Janus was suggested many times. Here's how TymmConner explained it: "As it is found at the end of the solar system, thus the beginning of the vast unknown cosmos, it should be named accordingly. The Roman Deity for endings and beginnings is Janus."

— Celo. BillGoodwin explains: "Latin meaning conceal, heaven, keep secret, be silent, cover, hide, keep back, veil, hush"

— Proserpina. AndreaBlankiship writes: "The planet name definitely has to remain Roman. You can't break up a set. To that end I suggest Proserpina. She is in the underworld and not seen for great lengths of time, near Pluto, master of the underworld." And Dean Lovett adds: "She was abducted by Pluto (god of the underworld). Her mother's search for her are subject of Roman art and literature."

— Black Star. User33297 writes: "In honor of David Bowie."

And here is where you vote. We'll be in touch with the winner so we can send them some NPR swag:

NPR VOTE FOR PLANET NINE'S NEW NAME!

Record-Busting Star Explosion Baffles Sky Watchers

A mind-boggling stellar explosion is baffling astronomers, who say this cosmic beast is so immensely powerful that no one's sure exactly what made it go boom.

The recently discovered inferno is about 200 times more powerful than a typical exploding star, or supernova, and 570 billion times brighter than our sun. It was first spotted in June by the All-Sky Automated Survey for Supernovae, nicknamed the "Assassin" project, so it's called ASASSN-15lh.

Astronomers describe their finding in a study published Thursday in the journalScience. 

Even though it's the brightest supernova on record — if indeed it is a supernova — it can't be seen with the naked eye from Earth, since it is 3.8 billion light-years away.

Even telescopes don't help much. "It looks like a little smudge," says Subo Dong, an astronomer at the Kavli Institute for Astronomy and Astrophysics at Peking University. "This is because it's so far away. It doesn't look so spectacular."

And if you could get into a spaceship and fly closer, you wouldn't want to, says astronomer Ben Shappee, at the Carnegie Observatories. That's because this monster puts out a lot of ultraviolet radiation, so if you actually got close enough to get a good look, "you would be dead right away," he points out.

Initially, the scientists didn't realize just how bright this beast was.

"We knew it was probably a supernova, but we didn't know at that time how interesting or how important it is," Dong recalls.

But soon, more observations from a different telescope made him realize "it was the most luminous supernova yet discovered." Dong says he was so excited when he got the news by email one night at 2 a.m., he couldn't go back to sleep at all.

Supernovas have captured the imaginations of sky watchers since ancient times. The first one was observed nearly 2,000 years ago. What's more, you wouldn't be here without them, because almost everything in your life is made up of the remnants of these violent stellar deaths.

"If you look around here on Earth, anything that's not hydrogen or helium was actually made inside of a star," explains Shappee. "It actually has to go through a supernova explosion to be distributed across the galaxy."

This new one is more than twice as bright as the previous record holder. What's powering it?

"Honestly, the answer is, 'We don't know,' " says Dong.

Astronomers will continue to watch it in the coming months with all kinds of telescopes, including the Hubble Space Telescope. Shappee says he is not sad that this explosion has already peaked and will slowly fade.

"We get more and more information — you see basically deeper and deeper into the supernova the longer you observe it," he says. "How it changes with time can give us additional information."

Edo Berger, an astronomer at Harvard University, says this find is exciting because "it's often, I think, the most extreme events that teach us the most about the range of possibilities that the universe comes up with, especially when it comes to exploding objects."

Most supernovas are the result of some sort of exploding star, says Berger.Superluminous supernovas are at least 10 times brighter than more garden-variety ones, and they're rare. Scientists know only of about 30 of these more powerful explosions, and while they have theories about what drives them, ASASSN-15lh is so extreme that current models can't explain it.

"The event itself seems to be coming from the center of the galaxy," says Berger. "And so I think that raises the possibility that it could be related to the supermassive black hole that resides in the center of a galaxy like that. And perhaps it is due to a very different mechanism than the explosion of a star." Perhaps a star got too close to the black hole, which is now ripping it to shreds.

"It's a story that continues to evolve. It will be interesting to see where we are a year from now," says Berger. "We might have a completely different version or story of what we think this object is."

Still, while this explosion is awesome, Berger says it's not the biggest bang astronomers have seen. Gamma ray bursts, for example, are much more energetic and luminous.

"In the world of supernova explosions, if this is what this object really is, then it is currently the record holder," says Berger. "But relative to a gamma ray burst, in fact, this explosion is actually kind of puny." npr

The Stuff We've Left In Space

In 1957, humans launched a satellite into orbit, Sputnik-1.

The same mission also created our first piece of space junk: the rocket body that took Sputnik into space.

By the year 2000, there were hundreds of satellites in orbit — and thousands of pieces of space junk, including leftover rockets and pieces of debris.

And today? According to the Royal Institution in London, there are about 20,000 pieces of tracked space debris, ranging from larger than an apple to as big as a school bus. (There are far more objects smaller than that, including millions of pieces of debris too tiny to track, according to NASA.)

Stuart Grey of University College London created a visualization showing how those larger pieces of junk proliferated over time — and how single events, like a Chinese test launch in 2007 or the collision of two satellites in 2009, could create thousands of pieces of space trash.

You can see a short preview above, or try out the interactive version on the Royal Institution's website. npr

Historic Rocket Landing For Blue Origin's

Star Wars: The Force Awakens trailer

Distant Pluto Comes To Life

Pluto is not dead. That's the bottom line, according to new research published in the journal Science. The dwarf planet is home to mountains, glaciers and a hazy atmosphere that stretches for a hundred miles above the surface.

"It is this really active dynamic world," says Cathy Olkin, the deputy project scientist of NASA's New Horizons mission, which flew past Pluto on July 14.

Even though the spacecraft whizzed past Pluto months ago, new results are still coming back. That's because data flows at a trickle over the more than 3 billion-mile chasm between New Horizons and Earth. "It is way slower than an old dial-up connection," Olkin says. 

The newly published results provide an official radius for Pluto of 1,187 kilometers (smaller than Earth's moon). Olkin says the research also shows that the large, heart-shaped feature on Pluto's southern hemisphere is a glacier made of carbon monoxide ice.

Pluto also has a nitrogen atmosphere mixed with different hydrocarbon molecules. "There's widespread haze to a really high altitude, like a hundred miles above the surface," Olkin says.

Researchers still want to learn why Pluto is so active. One possibility is that the dwarf planet has some sort of heat source deep within its core that causes glaciers to form and mountains to erupt from the surface.

But Michael Brown, an astronomer from Caltech not associated with the work, says other possibilities should be considered. "They have yet to demonstrate that internal heat is required for any of the features seen on Pluto," he says. For example, it could be that the ices on the surface move around and change the landscape.

Either way, Brown says, this look at Pluto is incredibly valuable. Astronomers now know that it is one of a whole class of "dwarf planets" lurking at the edge of our solar system.

"By looking at Pluto, we learn about the many many other things like it in the outer solar system," Brown says. "That's the reason why I am super excited about this." npr

Sexual Harassment Case Shines Light On Science's Dark Secret

A sexual harassment case is sending shock waves through the scientific community this week, and raising questions nationwide about how common sexual harassment is in science and why so little is typically done to stop it.

A six-month investigation by the University of California, Berkeley concluded in June that a faculty member, renowned astronomer Geoffrey Marcy, violated multiple sexual harassment policies over the course of a decade.

Marcy has been a leader in the hunt for Earth-like planets beyond our solar system, was head of a $100 million project aimed at finding life on other planets, and has often been touted as a possible candidate for the Nobel Prize.

But he resigned Wednesday after a number of faculty members and students in his department publicly released letters condemning his inappropriate behavior with students, and the university's inadequate response in dealing with it.

The school had kept its investigation private — even from its own faculty — until the online news outlet BuzzFeed broke the story last week.

Aside from confirming that "Marcy violated campus sexual harassment policy," the university released no details about what the investigation found. But according to BuzzFeed, the report concluded that Marcy's offensive behavior included unwanted massages, kissing and groping of at least four students, from 2001 to 2010.

One of these students was Sarah Ballard, now a postdoctoral fellow in astronomy at the Massachusetts Institute of Technology. She first met Marcy a decade ago when she was an undergraduate at Berkeley. He taught her astronomy class and showed special interest in her career, she tells NPR.

"To have a really renowned scientist praise you — and praise your ability — you can imagine, was really encouraging to me," she says.

At first, she and Marcy met a few times at cafes around campus, where they talked about astronomy and her career. But sometimes, she says, the conversation became too personal. He talked about when he was young and about having sex with a former girlfriend.

Then one day, Marcy gave Ballard a ride home. He parked the car by her house. "The fact that we were in the car together suddenly made me feel really uncomfortable," she says. "I think I really realized that the tenor of the mood was really wrong."

As Ballard started to get out of the car, the professor "reached over and was rubbing the back of my neck," she says. She left the car — and stopped getting together with Marcy outside of class.

Ballard says she was afraid to report Marcy. She didn't want to hurt her chances of going to graduate school. It's a common and very real conundrum for many women hoping to pursue university research careers, says Katie Hinde, a biologist at Arizona State University.

"Academia has a particular climate that allows sexual harassment, sexual assault and sexual abuses to persist," Hinde tells NPR. Last year, she co-authored one of the few studies aimed at figuring out how common sexual harassment is in science.

Hinde and her colleagues surveyed roughly 500 women doing fieldwork in a range of scientific disciplines. Seventy percent of those women told the researchers they had experienced sexual harassment, often from their mentors or supervisors — "people who had power over their career, who had power over their research," Hinde says.

In science, letters of recommendation from mentors are particularly crucial to obtaining a coveted faculty position, Hinde says. When a mentor sexually harasses or assaults a woman, it backs her into a corner: She can either report the offense, and possibly hurt her career. Or she can try to ignore it.

In fact, most harassment is never reported, says Heather Metcalf, research director of the Association for Women in Science.

Women are often told to keep quiet about lewd comments, touching and leering, she says. "There is a bit of a norm for those behaviors to sort of be brushed off, rather than be taken seriously."

An incident last summer involving the prestigious journal Science shows how common this attitude is, Metcalf says. A young female scientist wrote to the journal's advice column, asking what she should do about a situation in the lab where she worked.

"She was really enjoying the scientific work she was doing, but she was feeling really uncomfortable because she kept catching her supervisor trying to take a peek down her blouse," Metcalf says.

The magazine columnist essentially advised the woman to say nothing — to turn a blind eye, Metcalf says. Science eventually retracted the column.

But the culture of keeping silent about sexual harassment continues.

In Marcy's case, it took years of complaints before the university took up its investigation. Then it disciplined him privately.

The university, which declined an interview with NPR, confirmed in a written statement that Marcy was told to follow strict behavior guidelines or "be immediately subject to sanctions that could include suspension or dismissal." This agreement was the "most certain and effective option for preventing any inappropriate future conduct," according to the statement.

Michael Eisen, a molecular biologist at Berkeley, disagrees.

"In essence the university convicted him," Eisen says, "and what was so stunning to me was that Marcy got, at best, something you would describe as a slap on the wrist."

By not punishing him, Eisen says, "they're all but ensuring this kind of behavior is going to continue from others. Basically they're saying there are no consequences for this type of behavior."

In the days since the news got out, many scientists have demanded consequences.

Thousands of scientists have signed an online petition supporting the women Marcy harassed. And 24 faculty members in the department of astronomy at Berkeley signed and released a letter Monday that said, in part, "we believe that Geoff Marcy cannot perform the functions of a faculty member."

Marcy hasn't responded to NPR's request for an interview. He denies some of the allegations, but prior to his resignation, and to the publication of the BuzzFeed story, he posted a public apology "for mistakes I've made" on his faculty website.

Scientists Confirm There's Water In The Dark Streaks On Mars

For several years, a satellite orbiting Mars has seen streaks flowing from Martian mountains during warm periods on the surface. Scientists have now confirmed that water is involved.

Scientists have caught Mars crying salty tears.

Photos from NASA's Mars Reconnaissance Orbiter show dark streaks flowing down Martian slopes. The streaks appear in sunny spots or when the weather is warm, and they fade when the temperature drops.

Water was suspected to be involved, but now scientists have confirmed its presence. The new analysis, published in Nature Geoscience, shows salts mixed with water when the streaks are darkest. The water disappears when the streaks lighten.

Streaks a few hundred feet in length appear on the walls of Garni crater on Mars. Scientists suspect they are formed by the flow of briny, liquid water on Mars.

"It's only when these streaks are biggest and widest that we see evidence for molecular water," says Lujendra Ojha, a graduate student at the Georgia Institute of Technology.

Ojha cautions this isn't the same as streams trickling downhill on Earth. Standing on the streaks would be like standing on a hot beach on Earth and dribbling a little water out of a drinking bottle. "You would just see a hint of wetness," he says.

The lines appear on slopes with exposure to sunlight. Researchers now believe that the warm sun may cause water to begin flowing.

Ojha says the water could be important for future exploration of Mars. It might be that astronauts could one day use it for everything from drinking water to rocket fuel, but that depends on how much there is.

The water could be coming from a subsurface reservoir, but that's not the only option, Ojha says. Ice, or even moisture in the atmosphere, could also be causing the streaks.

"We're not entirely sure what the source of the water may be," he says. npr

More images available at nytimes.com/interactive/2015/09/28/science/space/mars-nasa-flowing-water.html

More Evidence for Coming Black Hole Collision

The apocalypse is still on, apparently — at least in a galaxy about 3.5 billion light-years from here.

Last winter, a team of Caltech astronomers reported that two supermassive black holes appeared to be spiraling together toward a cataclysmic collision that could bring down the curtains in that galaxy.

An illustration of two black holes orbiting each other. The black hole in the center of the image is starved of gas by the black hole at the left, making the gas cloud of the black hole on the left brighter. Credit Illustration by Zoltan Haiman, adapted from Farris et al. 2014

The evidence was a rhythmic flickering from the galaxy’s nucleus, a quasar known as PG 1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release as much energy as 100 million supernova explosions, mostly in the form of violent ripples in space-time known as gravitational waves that would blow the stars out of that hapless galaxy like leaves off a roof.

Now a new analysis of the system by Daniel D’Orazio of Columbia University and his colleagues has added weight to that conclusion. Mr. D’Orazio, a graduate student, and his colleagues Zoltan Haiman and David Schiminovich propose that most of the light from the quasar is coming from a vast disk of gas surrounding the smaller of the two black holes. nytimes.com

Earth Blamed for Cracks in Moon

The moon is shrinking, and Earth is to blame for how the moon’s crust has cracked.

A prominent ridge on the moon's surface, one of thousands that formed by the cracking of the moon's surface as it contracted. Areas in blue are at lower elevations; areas in red are higher. CreditNASA


Scientists reported the shrinkage in 2010, when researchers, led by Thomas R. Watters of the Smithsonian’s National Air and Space Museum, picked out cracks in images taken by NASA’s Lunar Reconnaissance Orbiter.

They counted 14 ridges, formed when one side of the fracture slips over the other, but the orbiter’s high-resolution camera had covered only about 10 percent of the moon’s surface. Five years later, more than three-quarters of the surface has been photographed, and the scientists now count more than 3,200 ridges, most quite small — less than six miles long and tens of yards high.

If the moon were shrinking uniformly, then the cracks and ridges should be pointed every which way. Instead, Dr. Watters and his colleagues found that around the equatorial and midlatitude regions, there was a preponderance of north-south ridges, while near the poles, the faults tended to run east-west.

What they figured out is that the tidal forces of the Earth pulling on the moon, while small, generated enough stress to break the moon’s crust in the observed pattern. The new study was published in Geology. nytimes

One Small Bite For Man: NASA Astronauts To Eat Space-Grown Food

Today on the International Space Station, a batch of romaine lettuce became the first food grown and consumed in space. The leaves were harvested from NASA's experimental plant growth system called Veg-01, a microgravity environment in which plants grow from seed "pillows" under primarily red and blue LED lights.

In 2014, an astronaut on NASA Expedition 39 grew and harvested the first plants from Veg-01 and then sent the plants back to earth for food safety analysis. This time around, the crew members of Expedition 44, including astronaut Scott Kelly, who is four months into a yearlong space mission, got to enjoy the bounty. Kelly activated the seed pillows on July 8, and then tended to the plants for 33 days before harvesting.

While this isn't NASA's first experiment designed to test the growth of plants in controlled environment agriculture settings (scientists previously designed a habitation to grow plants on the moon), this is the first and only experiment to evaluate the effect of plant life on humans in space.

While some fresh foods are already on the menu at the International Space Station, a NASA scientist says crew members must wait for shipments of foods like apples and carrots, and then consume it quickly. The ability to grow sustainable plants in space opens up a world of possibilities for prolonged space exploration, both in terms of improved nutrition and beyond.

Not only do fresh vegetables contain vital vitamins and nutrients, NASA says there are likely psychological benefits from caring for a small piece of green, which will be increasingly important as space voyages become longer. This idea is central to NASA'sJourney To Mars project, which aims to send humans to Mars in the 2030s. npr

Geologic Mapping of Mars

Geologic mapping is an integral part of exploration and understanding a planetary landscape, because it shows the relationships between geologic units and helps delineate the history of a surface. New orbiting spacecraft are obtaining data with progressively higher resolution, and as a consequence maps constantly need to be updated and improved. Moreover, as researchers' various needs and areas of focus change, maps of different areas and scales are required.

Dr. Grant and colleagues are currently mapping the geologic history and landscape evolution of portions of Margaritifer Terra at a scale of 1:500K1-3 (Figure 2). The map areas in the west are characterized by the large, multi-ring Ladon and Holden impact basins, channels comprising the Uzboi-Ladon-Morava outflow system, highland intercrater plains, late valley network activity, and a range of structural geology such as minor compressional and extensional faults. To the east, the map areas are dominated by Samara, Parana, and Loire Valles, some of the best integrated and largest valley network systems on Mars This region is of particular interest because two of the four final candidate landing sites that were considered for the Mars Science Laboratory (MSL) mission, Holden and Eberswalde craters, are located within the mapping areas.

Figure 1. Geologic maps of sections of eastern (top) and southwestern (bottom) Margaritifer Terra, Mars1-2, at a scale of 1:500,0001. Maps shows a variety of geomorphic units including one of the highest densities of preserved valley network drainage systems on the planet. Maps were published in 20091 and 20132 (left and right, respectively).

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