TIME space

The Ten-Year Journey to Land on a Comet

The first spacecraft to attempt such a daring maneuver could reveal secrets of the solar system

Traveling in space takes a lot of patience—but the wait is often worth it. That’s a fact the European Space Agency (ESA) is about to learn in a very big way.

On November 12, the ESA’s Rosetta spacecraft will drop an oven-sized research vessel onto the surface of a comet where it will perform a variety of scientific experiments. The mission—the first of its kind—has been 10 years in the making. If successful, it could reveal secrets about the anatomy of comets, the formation of our solar system and perhaps even the origins of life. “What we believe is that we will study the most primitive material in the solar system,” says Dr. Gerhard Schwehm, who served as Rosetta’s mission manager at the ESA from 2011 until his retirement earlier this year.

Comets are considered the bones of the ancient solar system. Their long, elliptical orbits mean they spend most of their time in the deep freeze of space, far from the sun, which preserves their original composition. And their small mass means very weak gravity, which in turn means low gravitational pressure and heating—something else that messes with internal chemistry on larger bodies.

Rosetta’s target comet, Churyumov-Gerasimenko, known as 67P, resembles nothing so much as a 2.5-mile long (4 km) unshelled peanut, albeit one tearing through space at 11 miles per second (39,600 mph, or 63,730 k/h). It hails from a region called the Kuiper Belt, a band of icy bodies beyond Neptune’s orbit. Unlike asteroids, comets contain a great deal of ice. As they approach the sun, some of that ice vaporizes into a cloudy atmosphere called a coma. When charged particles called solar wind hit the comet, the gas streams away, forming a blue ion tail.

A photo illustration of the Rosetta probe and Philae lander above the 67P/Churyumov-Gerasimenko comet. ESA/Getty Images

In the past three months, Rosetta has has been flying along beside 67P, taking numerous measurements of its chemistry, including the composition of its singularly unpleasant gasses. Gorgeous from a distance, the comet emits copious amounts of both ammonia and hydrogen sulfide, which means that if you could smell it (and be thankful you can’t) you’d get a nose full of rotten eggs, horse stable and formaldehyde.

But the real fun and the real risk will start on when Rosetta releases its probe—dubbed Philae—to attempt its historic landing. The vehicles will separate at a distance of about 14 miles (22.5 km) above the comet. A 14-mi. plunge to the surface of the Earth would be over very quickly, but with 67P’s gentle gravity, Philae’s fall will take 7 hours. Once it makes contact with the comet’s surface, a thruster on its top will ignite for one minute to keep it from bouncing away, while two harpoons will anchor it to the ground.

Philae carries 10 scientific research tools to study the surface and interior of the comet, including a camera, a thermometer, and seismographs in its feet to listen to the cracks and pops within the core as the comet out-gasses. It also carries a drill to collect and analyze sub-surface samples. Even the harpoons have a research purpose, using sensors to detect the resistance of the ground they penetrate. All of this data may offer clues for the conditions—temperatures, pressures and other variables—in which the comet’s dust was originally formed.

“It shows the evolution of the universe,” says Schwehm.

And perhaps the evolution of biology too. It’s possible that water and the life-forming molecules within it arrived via comets that smashed into Earth billions of years ago. If there are commonalities between our oceans and the icy stuff on the comet—namely, organic compounds such as nucleic acids and amino acids—we can, as Schwehm says, “put pieces of the puzzle together.”

Throughout its stay on 67P, Philae will remain in constant contact with Rosetta, which will relay its transmissions the 317 million mi. (510 million km) back home, a journey that even at light speed takes 30 minutes. When they are on opposite sides of 67P, the two probes will transmit radio waves to each other through the body of the comet itself to study its internal structure.

Philae’s stay on 67P will be a short one. Once it is in place, a 64-hour countdown begins before the probe’s on-board battery runs down. Solar panels covering nearly every surface of Philae’s body can provide some juice, but the weak sunlight that bathes the probe at such great solar distances cannot keep it running in even a low-power mode for more than a few weeks.

That seems an awfully small payoff for the 10 years it took the spacecraft to arrive—a spiraling trip that included three fly-bys of Earth and one of Mars to pick up speed thanks to the planets’ gravity. But Rosetta has a longer life ahead of it after Philae dies, escorting 67P around the sun and observing its rate of water loss, surface temperatures, and the way its shape changes as it loses mass. It will keep that job up as long as it can, before accompanying the tiny world back to the distant solar system, and breaking contact with Earth forever.

TIME space travel

Watch the ISS Crew Land Safely Back on Earth

Footage from NASA shows Maxim Suraev, Alexander Gerst, and Reid Wiseman touch safely back down to earth in the Soyuz-13M capsule at 10:58 p.m. EST

Three crew members from the International Space Station (ISS) landed safely back on earth in Kazakhstan on Sunday after spending 165 days in orbit.

The trio were part of Expedition 41 and were conducting hundreds of scientific experiments and other research focusing on how humans can stay healthy while spending long durations in space.

Commander of the station, Russian cosmonaut Maxim Suraev, and flight engineers Alexander Gerst, from the European Space Agency, and Reid Wiseman, an astronaut from NASA, completed a remarkable 82 hours of research in a single week in July.

During their time on board the ISS they traveled more then 70 million miles.

TIME astronomy

A Fireball Was Seen Streaking Across the Texas Sky on Saturday Night

The flash was bright enough to be picked up by a NASA camera over 500 miles away

A fireball described as being brighter than the moon was seen streaking across the sky in Texas Saturday night.

The American Meteor Society says more than 200 residents reported seeing a very bright and fleeting flash at around 8.45pm, CNN reports.

Dr. Bill Cooke heads NASA’s Meteoroid Environment Office and said the fireball was a meteor.

“This was definitely what we call a fireball, which by definition is a meteor brighter than the planet Venus,” he said.

The meteor, Cooke estimates, was over four feet wide, weighed about 4,000 pounds and was a dazzling five times brighter than the moon.

“This event was so bright that it was picked up on a NASA meteor camera in the mountains of New Mexico over 500 miles away, which makes it extremely unusual,” he said.

Read more at CNN

TIME Food

USDA Approves Genetically Engineered Super Potato

potato
Stuart Minzey&—Getty Images

But some food-safety experts aren't psyched about the spud

The U.S. Department of Agriculture on Friday approved a genetically engineered potato that is resistant to bruising and cuts down on a possible cancer-causing substance, though some food-safety experts aren’t so excited about the super spud.

The Innate Potato, trademarked by Simplot, contains the DNA of other kinds of potatoes mixed in through a process known as RNA interference technology, The Guardian reports.

“If this is an attempt to give crop biotechnology a more benign face, all it has really done is expose the inadequacies of the US regulation of GE crops,” Doug Gurian-Sherman, senior scientist at Center for Food Safety, said in a statement. “We simply don’t know enough about RNA interference technology to determine whether GE crops developed with it are safe for people and the environment.”

Simplot says the new potato minimizes the creation of an amino acid that at high temperatures reacts with certain chemicals to become acrylamide, a substance the International Agency for Research on Cancer has called a “probably human carcinogen.”

The company has reportedly worked on the potato for more than a decade, but activists are already asking one of the company’s biggest customers, McDonald’s, not to buy it.

[The Guardian]

TIME movies

What Interstellar Got Right and Wrong About Science

INTERSTELLAR
Matthew McConaughey in 'Interstellar' Warner Brothers—Melinda Sue Gordon

Even a movie largely based on real science is bound to bend the rules a bit

If you’re one of the estimated 3 gajillion people who have seen or will see Chris Nolan’s blockbuster movie Interstellar, one thing is already clear to you: this is not a documentary. That means it’s fiction, specifically science fiction, which is how you get the sci and the fi in the sci-fi pairing. So if you go into the movie looking for a lot of scientific ‘gotcha’ moments, let’s stipulate up front that you’re going to find some.

That said, part of Interstellar’s considerable appeal is that it does go heavy on the science part of things. Nolan enlisted Caltech cosmologist Kip Thorne as the film’s technical adviser, and Thorne kept a whip hand on the production, ensuring that the storyline hewed as closely as possible to the head-crackingly complex physics that govern the universe.

So where did Interstellar play it absolutely straight and where did it take the occasional narrative liberty? Here are a few of the key plot points and the verdict from the scientists (warning, there may be spoilers ahead):

1. A worm hole could open in space, providing a short cut from one side of the universe to the other. Verdict: Mostly true

Worm holes are a pretty well-accepted part of modern cosmology and it’s Thorne’s theorems that have helped make them that way. The idea is that if you think of space-time less as a void than as a sort of fabric—which it is—it could, under the right circumstances fold over on itself. Punching the necessary holes in that fabric so that you could make your universe-transiting trip would be a bit more difficult. That would require what’s known as negative energy—an energetic state less than zero—to create the portal and keep it open, says Princeton cosmologist J. Richard Gott. There have been attempts to create such conditions in the lab, which is a long way from a real wormhole but at least helps prove the theory.

One bit of license the Interstellar story did take concerns how the wormhole came to be. It takes a massive object to generate a gravity field sufficient to fold space-time in half, and the one in the movie would have to be the equivalent of 100 million of our suns, says Gott. Depending on where in the universe you placed an object with that kind of mass, it could make a real mess of the surrounding worlds—but it doesn’t in the movie.

2. Getting too close to the gravity well of a massive object like a black hole causes time to move more slowly for you than it would for people on Earth. Verdict: True

For this one, stay with space-time as a fabric—a stretched one, like a trampoline. Now place a 500-lb. cannon ball on it. That’s your black hole with its massive gravity field. The vertical threads in the weave of the fabric are space, the horizontal ones are time, and the cannon ball can’t distort one without distorting the other, too. That means that everything—including how soon your next birthday comes—will be stretched out. Really, it’s as simple as that—unless you want to spend some time with the equations that prove the point, which, trust us, you don’t.

3. It would be possible to communicate to Earth from within a black hole. Verdict: Maybe

The accepted truth about a black hole is that its gravitational grip is so powerful that not even light can escape—which is how it got its name. But even physics may have loopholes, and one of them is something known as Hawking radiation, discovered by, well, guess who. When a particle falls into a black hole, the fact that it’s falling creates another form of negative energy. But nature hates when its books are unbalanced—a negative without a corresponding positive is like a debit without a credit. So the black hole emits a particle to keep everything revenue- neutral. Zillions of those particles create a form of outflowing energy—and energy can be encoded to carry information, which is how all forms of wireless communication work. That’s hardly the same as being able to radio down to Houston from within a black hole’s maw, but it takes you a big step closer.

4. It would be possible to survive the leap into the black hole from which you hope to do your communicating in the first place. Verdict: False—except…

Cosmologists vie for the best term to describe what would happen to you if you crossed over a black hole’s so-called event horizon, or its light-gobbling threshold. The winner, in a linguistic landslide: spaghettification—which does not sound good. But that nasty end may not happen immediately. “Most people would agree that a person who jumps into a black hole is doomed,” says Columbia University cosmologist and best-selling author Brian Greene, “but if the black hole is big enough, you wouldn’t get spaghettified right away.” That’s small comfort, but for a good screenwriter, it’s all the wiggle room you need.

5. And finally: Anne Hathaway could move through time and space and help save all of humanity and her hair would still look fabulous. Verdict: Who cares? We wouldn’t have it any other way.

Read next: Watch an Exclusive Interstellar Clip With Matthew McConaughey

TIME astronomy

Rogue Stars Are Everywhere You Look

A recent study found that as many as half the stars in the entire universe live outside galaxies

Astronomy 101 tells us that galaxies are massive collections of stars, gas and dust—”island universes,” early 20th-century stargazers used to call them–glowing with the light of hundreds of billions of stars, surrounded by darkness. Sure, the occasional star manages to escape the gravitational bonds of its galactic home, but that’s a rare event.

That’s what astronomers thought, anyway. But two new discoveries have made it startlingly clear that stellar liberation isn’t even remotely uncommon. Last week, a paper in the Astrophysical Journal reported that as many as 200 billion stars are roaming free in a cluster of galaxies known as Abell 2744 some four billion light-years from Earth.

But that pales next to a study just published in Science. An international team of astronomers has found that as many as half the stars in the entire universe live outside galaxies. “It is remarkable that such a major component of the universe could be hiding in plain sight,” writes S.H. Moseley, of the Laboratory for Observational Cosmology at NASA’s Goddard Space Flight Center in Maryland in an accompanying commentary.

“Remarkable” is probably the understatement of the year. But in fact, those billions of quintillions of orphan stars really have been visible all along—in a sense, anyway. Astronomers have had evidence for at least a half a decade, thanks to the Spitzer Space Telescope, that the cosmos is suffused with a faint glow of infrared light whose sources are too faint to identify. Some of it presumably comes from the very first galaxies that lit up after the Big Bang, too small to see individually but producing an overall haze of infrared light.

But that’s just a presumption, and, says James Bock, an astronomer at Caltech and a co-author of the paper, “I was kind of skeptical about the the Spitzer results anyway.” so a group of astronomers led by Caltech’s Michael Zemcov, at Caltech, decided to find out what’s actually going on. They couldn’t make their observations from the ground because the atmosphere itself glows with infraed light. “It’s pretty horrible,” says team member and co-author James Bock, also at Caltech. “So we need to get above the atmosphere—but not for a long time.”

So they sent their instruments up on a sounding rocket, which shot up to about 200 miles in altitude, then parachuted back down. Their goal was not to find the sources of infrared light directly, but rather to see how the intensity of the light varied across a relatively wide swath of sky.

It turned out to vary significantly, with brighter patches spanning 20 times the area of the full Moon. “They’re associated with clusters of galaxies,” Bock says, “but we calculated how much infrared light could be coming from the clusters themselves, and it wasn’t enough.”

Instead, they concluded, it must be coming from stars completely outside the galactic clusters, flung into intergalactic space as galaxies collided, their clashing gravitational fields whipping stars in all directions. The same process presumably send stars flying around within Abell 2744, the cluster described in last week’s announcement—but on a much vaster scale.

The discovery of huge numbers of stars nobody knew about doesn’t necessarily alter our overall view of the cosmos. It doesn’t refute the existence dark matter, or of dark energy, or the Big Bang itself. But it does give astronomers a whole new collection of objects to think about. “If you want to understand the global process of star formation,” says Bock, “you can’t just look at galaxies.” If you do, he says, “you’ll miss all the action.”

TIME Archaeology

DNA Study Dates Eurasian Split From East Asians

EU Eurasian Split
The skull of the fossil of Kostenki XIV that was found in 1954 near Kostenki-Borshchevo, in what is now western Russia AP

The study concludes that Kostenki man shared genetic sequences with contemporary Europeans, but not East Asians

(BERLIN) — The human populations now predominant in Eurasia and East Asia probably split between 36,200 and 45,000 years ago, according to a study released Thursday.

Researchers used new techniques to analyze genetic samples from the shin bone of a young man who died at least 36,200 years ago near Kostenki-Borshchevo in what is now western Russia. The study, published in the journal Science, concludes that Kostenki man shared genetic sequences with contemporary Europeans, but not East Asians.

A separate study published last month in the journal Nature determined that a 45,000-year old sample found in Siberia contained sequences ancestral to both modern East Asians and Europeans.

Taken together, these two studies suggest a time frame of about 9,000 years in which the two genetic populations could have diverged, said Eske Willerslev, an evolutionary biologist at the University of Copenhagen, Denmark, one of the authors of the Science paper.

Even on its own the Kostenki sample challenges previous theories that modern Europeans emerged only when hunter-gatherers mixed with a farming population that moved in from the Middle East after Ice Age glaciers receded from Europe about 10,000 years ago, the start of a period known as the Neolithic.

“People had largely tended to think that Europeans today were mostly influenced by the Neolithic expansion from the Middle East,” said Sarah Tishkoff, a professor of genetics at the University of Pennsylvania who wasn’t involved in the latest study. “But if they’re correct they are suggesting that this person 36,000 years ago already had some similarity to the people who contributed to this Neolithic expansion from the Middle East.”

Although Kostenki man — who had dark skin, brown eyes and was relatively short — belonged to a group of humans that ultimately died out, the DNA fragments he left are enough to draw a line in European genetic history going back at least 36,000 years, said evolutionary biologist Marta Mirazon Lahr of the University of Cambridge, another author of the Science study.

TIME animals

Study Shows Bats Jam Each Other’s Sonar to Snatch the Best Prey

163436740
Yves Adams—Getty Images

The bats reportedly block each other's frequencies to hinder their hunting ability

The use of sonar by bats for hunting has been well-documented over the years, with the nocturnal winged mammals using ultrasonic clicks to target their prey in a phenomenon called echo-location.

But a new study, published on Friday in the journal Science, reveals that bats also sabotage rivals by jamming each other’s sonar frequencies so that they can grab the most appetizing prey.

“This jamming signal covers all the frequencies used by the other bat, so there’s no available frequency to shift to,” Johns Hopkins University researcher Aaron Corcoran, who co-authored the study, told the New Scientist.

Read more at New Scientist

TIME space

Orbital Sciences CEO Gives Reason for Antares Rocket Explosion

A failure may have occurred in the rocket's engine

Investigators believe they know what made the Antares rocket explode just seconds after it lifted off from a Virginia launch pad. Orbital Sciences’ president and CEO David Thompson said one of two main engines used to launch the rocket failed.

Thompson also said Orbital Sciences plans on continuing with its nearly $2 billion contract with NASA to deliver supplies to the International Space Station. The failed AJ26 engine will no longer be used to launch the rocket.

TIME space

New Mesmerizing Image of a Young Star

ALMA image of the protoplanetary disc around HL Tauri
This is the sharpest image ever taken by ALMA ALMA (ESO/NAOJ/NRAO)

The detail in the image is far greater than anything even the Hubble could achieve

If someone had been around to see it, this is what our Solar System probably looked like when it was only a million years old (for the record, it’s nearly 4.6 billion now, and counting). This image was taken by the giant ALMA telescope, located in the high desert of northern Chile, which sees in radio wavelengths. The detail here is far greater than anything even the Hubble could achieve.

The glowing disk is dust and gas whirling around the young star, known as HL Tauri, located about 450 light-years from Earth in the constellation Taurus. The dark gaps are almost certainly places where the gravity of newly forming planets has swept the dust clean — exactly as Earth, Mars and the other planets in our mature Solar System did long ago. It’s a strong clue that our theories of how planets form are very much on the right track.

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