Surprising Study of Human Immune Responses Could Lead to Better Flu Vaccines

An “antibody landscape” map showing one person’s immune response to different strains of influenza (see text for more explanation). Center for Pathogen Evolution, University of Cambridge

Scientists make this season’s flu vaccine based on the strains of the virus that circulated during the last flu season. It’s a flawed approach, but it’s the best they can do given that it takes months to make the vaccine, and there’s no way—at least not yet—to predict how the virus might evolve in the interim. But a new computer modeling study suggests the human immune system has a better memory than scientists had thought for strains of the flu it’s encountered in the past. In the future, the researchers say, it might be possible to exploit this to design better vaccines.

Every year, the flu wreaks havoc around the world. It typically infects millions of people around the world every year and kills up to 500,000 in a typical year. National economies lose billions of dollars to medical care and missed workdays.

The flu vaccine helps soften the blow, but vaccine makers are in an arms race with the virus. The Global Influenza Surveillance Network (orchestrated by the World Health Organization) continuously collects samples from ill people all over the globe and in February each year chooses which strains to put in the vaccine. Months later, around November, people start rolling up their sleeves to receive a vaccine based on those one or two strains. But sometimes the virus mutates during the lag time between spring and fall, which renders the vaccine less effective.

“If the virus has evolved, the vaccine’s efficacy is not as good as it could be,” explains virologist Derek Smith from the University of Cambridge, “But it’s still better to be vaccinated than not at all.”

Smith thinks we can improve the vaccine, even if we can’t accurately predict the flu’s evolution yet. His new study published in Science today offers a new way to look at our immune system’s reaction to influenza. The team tracked 64 people in Vietnam for six years, analyzing their antibodies—proteins made by the immune system to flag invading pathogens for destruction—when they were infected with the flu.

They then created 3-D “antibody landscape” maps of each person’s immune response, says research assistant and co-author Sam Wilks. In the figure above, the colored dots represent different strains of flu, and the space between the dots reflect structural differences between those viruses. The 3-D landscape (blue) shows the individual’s varied immune response to all the strains (peaks indicate high immunity, valleys indicate low immunity).

The landscapes revealed something remarkable: when influenza infects someone, it not only triggers an immune response for that particular strain, but for all the strains of that type of flu that have ever infected the person. This phenomenon, named ‘back-boosting,’ means that our old immunity gets boosted every time we’re faced with a new flu virus. Typically, the back boost response was stronger for past strains that were closely related to the infecting strain.

The researchers think we make antibodies for past strains because our immune system’s memories of past viruses are activated more easily than they’d thought. The findings suggest that the flu vaccine provides much more protection than anyone thought against past versions of the flu that have infected a person. Someone infected with the flu last year will still make antibodies for that strain, regardless of what version of the vaccine they receive. “It’s essentially a free pass,” Smith said.

This means scientists can try to predict how the virus might mutate (an active area of research) and base a vaccine on that, without worrying about diminishing protection against current circulating strains. If last year’s strain is still around this flu season, a vaccine targeted for a novel strain will still offer a defense by stirring antibody production. “This opens up the possibility for vaccinating against a future virus,” explains Smith, “We don’t have anything to lose because it won’t make the vaccine any worse. The back boost covers our backs.”

Epidemiologist Michael Osterholm agrees. “This is potentially revolutionary work,” says Osterholm, who directs the Center for Infectious Disease and Research Policy at the University of Minnesota, “We’re a long way from changing our current policies, but this could really help. It also raises questions about how often do we need to be vaccinated if we can use this back-boost?”

It’ll be a while before a vaccine that takes advantage of the back-boost goes into a shot or nasal spray – the approach still needs to go through clinical trials, which Smith hopes to get started on within a couple years. Until then, he recommends you get your flu shot anyway.

The Cutest and Weirdest Wild Animal Incidents This Week

A newborn baboon cuddles a teddy bear after its mom refused to have her at Gaziantep Zoo, in Gazitantep, Turkey, November 15, 2014.  Kerem Kocalar/Anadolu Agency/Getty Images

This Week in Wild Animals for November 21, 2014

Starfish were deflating. Polar bears were going bald. Fur seals were raping penguins. A 400-pound tortoise named Benjamin Franklin made an appearance outside a Walmart.

This Week in Wild Animals is a public service for human beings compiled by Jon Mooallem, author of the bookWild Ones.

An orange remote-controlled dog, called FIDO, failed to scare geese away from an amphitheater in Cedar Rapids, Iowa. FIDO was the centerpiece of an elaborate goose-deterrence strategy deployed by the city parks department which, one official explained, would teach geese that the amphitheater was “not a good place to be, because that orange thing will chase us.” However, the official explained, “What we found is, that didn’t really happen.” The city was now considering identifying people who go walking near the amphitheater for exercise and recruiting them to “physically chase [the geese] and run them off.”

Police officers in England hazed 29 pilot whales with a helicopter to keep them from beaching. Virgin Atlantic flew 57 giant chicken frogs from London to Antigua. Law enforcement officers in Michigan assisted a skunk that had gotten its head stuck in a jar. (“It was a skunk in distress,” a police department spokesman explained.)

A Fijian photographer tied himself to the bottom of a stream to photograph hungry ducks.

A black bear in Florida snatched a three-year-old Yorkie named Brody and started carrying the dog up a tree when it was suddenly ambushed by Brody’s owner. “Erica hit the bear two times,” the woman’s fiancé told a reporter.  A woman walking her dog in New Hampshire was attacked by a coyote. (“There was something wrong with it,” the woman said, describing the animal.) In Arizona, a woman walking her dog was assaulted by a javelina, and in California, a woman walking her dog was gored by a three-legged wild boar.

Congui, a domesticated hutia, rides on the front door of an American classic car driven by its owner Rafael Lopez, in Bainoa, Cuba, November 17, 2014.  Ramon Espinosa/AP

Thousands of bats dropped dead from trees in Australia during a heat wave. A family in New Jersey discovered a colony of bats living in their son’s bedroom and set up a webcam to share their bats with the world. In China, a panda was attacked by a pack of martens and needed more than 100 stitches.

Officials in Washington state were arguing about who was responsible for the recovery and disposal of a humpback whale carcass, projected to cost $188,000. The whale had been floating close to shore for several weeks; earlier, a man had jumped into the water to “surf the whale” on a dare, even as several sharks busily picked the animal apart. (He subsequently conceded this was a “bad idea.”) A state fisheries employee insisted that, regardless of whatever one local mayor believed, the dead whale wasn’t his agency’s problem because whales are mammals, not fish.

A British zoo director was found guilty of allowing a flock of ibises to escape, then shooting them. A zoo keeper in India was arrested in connection with the disappearance of eight gecko lizards. “More arrests are likely to be made,” police said.

Montana celebrated one year of legalized roadkill-eating. (“It’s really exceeded my expectations,” one state legislator bragged.) In Nevada, a headless deer laying on the side of the road was creeping out commuters, and traffic in Venice, Florida “screeched to a halt” when drivers stopped to watch an “epic mid-air battle”between two bald eagles. Ultimately, the tussling eagles fell from the sky together and landed in a muddy ditch. In Virginia, a Cooper’s hawk flew into a Michael’s craft store where it killed and ate a songbird.

A three-year-old giant panda, attacked by wild martens, rests after receiving an operation in Guangyuan city, China, November 17, 2014.  AP

A baby baboon snuggled with a teddy bear. Vladimir Putin snuggled with a koala. Prince William promoted an Angry Birds tournament to “raise awareness” about the plight of the endangered pangolin. A squirrel made a movie with a GoPro.

A belligerent three-legged alligator was stealing fish from fishermen in Florida.  The proprietor of a Santa Monica sushi bar, known for its “its unique and exotic blend of seafood medley” plead guilty to serving his customers whale.

Fans spotted a crocodile walking around the sidelines at a rugby game in Papau New Guinea; the league CEO explained that the animal was “probably was there as a promotional stunt,” but couldn’t say for sure. A Cuban couple was domesticating a species of toothy rodent called the hutia, and reported the animals enjoy crackers, coffee and rum. A New York state senator was asked to judge a moose-calling contest, despite knowing very little about moose, and the US federal government put out another open call for nominations for its Wild Horse and Burro Advisory Board.

In New Jersey, a deer leapt through a glass window into an Estonian church in the middle of the night, then ran through the church’s office, splattering blood and scattering books and paperwork. Eventually, the animal leapt back through the window and disappeared. Reflecting on the incident, the church’s pastor said, “It’s mysterious and difficult to relate to, actually.”

A venomous snake appeared on a woman’s doorstep in Georgia, then—after she’d spotted it and called a pest control professional—bit itself in the neck, in an apparent act of suicide.

Absurd Creature of the Week: The Adorably Creepy Gliding Mammal That’s Basically Just a Big Flap of Skin

It’s a bird, it’s a plane, it’s…neither. It’s actually the colugo, a gliding mammal with no sense of decency.  Norman Lim

In 16th century Scotland, the alchemist John Damian, who was known to expense a suspicious amount of whiskey in his experiments to find the elusive philosopher’s stone, decided he could fly. He fashioned a pair of wings from feathers and “took off from the lofty battlements of Stirling Castle for a flight to Paris.” He didn’t make it to France, but he did plummet a few feet away from the castle and break a leg. The failure, he later claimed, was due to using feathers from chickens, which can’t so much fly, when he should have used eagle feathers instead.

More absurd creatures:

The Anglerfish and the Absolute Worst Sex on Earth

The Zombie Ant and the Fungus That Controls Its Mind

Enormous Hermit Crab Tears Through Coconuts, Eats Kittens

Really, the problem had more to do with mammals like us not being cut out for flight. Well, except for bats. There are, though, critters like sugar gliders and flying squirrels, which can pull off some pretty solid glides. But compared to the adorable and little-known colugo, they got nothin’. This is the most accomplished mammalian glider of all—on account of being essentially a giant flap of skin—capable of soaring an incredible 200 feet from tree to tree. Its expansive membrane, known as a patagium, stretches from its face to the tips of its digits all the way back to its tail, so “geometrically, it has the greatest surface area that you can have between those limbs without actually evolving an entire wing like bats did,” said conservation biologist Jan Janecka of Duquesne University.

With undeniable cuteness and way too much skin, the colugo is an aesthetic conundrum, like adorable old people. Norman Lim

With such a beautifully evolved body, the colugo, also known misleadingly as a flying lemur (more on that later), spends its nights leisurely gliding through the forests of Southeast Asia. Their skeletons, while not nearly as frail as those of bats, are thinner and more elongated than that of a squirrel, reducing their weight while increasing their surface area. And their huge eyes, Janecka says, gives them not only good night vision, but excellent depth perception—no insignificant advantage when you’re coming in for a hard landing on the trunk of a tree.

Colugos are such adept gliders that mothers have no problem bringing their babies along for the ride. And they’ll do so for quite some time, for their young are born highly underdeveloped. They’re not as helpless as, say, marsupial young ‘uns, which enjoy the comfort of their mother’s pouch, but certainly not as developed as most mammals.

The colugo’s unique comb-shaped teeth, which may help in feeding or grooming, but only when it’s not a skeleton though.  Top: Wikimedia. Bottom: Jan Janecka

Still, the newborns cling to mom as she sails around the rainforest in search of food, mostly sap and leaves and shoots. And as if the colugo’s flappy skin weren’t bizarre enough, its teeth are shaped like little combs. This could be helping them in some way to feed, says Janecka, or may play a part in grooming to snag parasites on their skin. That’s right. Colugos may be brushing their hair with combs built right into their faces.

Unfortunately, beyond watching mothers sail around with their babies, we don’t know much at all about the colugo’s social life. And efforts to keep them in captivity have largely been for naught. Remember that these are creatures used to gliding up to 200 feet, and good luck finding that kind of space in a zoo. “Basically their enclosures weren’t large enough to allow them to glide long distances,” said Janecka. “And because they couldn’t glide, they couldn’t keep their patagium well maintained and dry enough.” They developed infections on their skin, perhaps from a fungus, and died.

Ironically enough, it’s too much space in the wild that’s threatening some colugo populations. Deforestation can strand species in islands of trees, but even if loggers just thin out spots in the forest, it’s big trouble for the colugo. They’re the most accomplished mammalian glider on Earth, sure, but if there’s too much space between trees, the colugo runs the risk of sinking right to the ground. And as you can see below in the video from National Geographic (they strapped a camera to a colugo—enough said), the creature’s extra skin makes it all but worthless when anywhere but the canopy. It’s an easy target in a habitat packed with predators.

Of Parasites and Primates

Because colugos tend to live in isolated habitats and because they insist on emerging only at night, much of what we know about them comes from anecdotal evidence. Case in point: colugo doo-doo. It … moves.

“I’ve seen some videos of fecal material that they’ve dropped where there’s so many worms it’s actually moving,” said Janecka. “It’s squirming around.” The colugo digestive tract, it seems, has a really, really high parasite load. “And that whole dynamic, whether it happened to be in a population that has a lot of parasites or it’s something that’s more normal for the colugos that they’ve learned to deal with, that’s one of those unknown questions at this point.”

What is abundantly clear is that the colugo has a very long digestive tract, which makes sense for a creature that eats trees. That stuff takes a whole lot of time to digest. But such long guts could also be acting as a sort of mansions for parasitic worms, which have lots of room to make themselves comfortable. Until someone starts studying colugo turds at length, though, we’ll have to leave this one a mystery.

A colugo and her baby. “UGH, MOM. Have some decency. You’re embarrassing me.”  Norman Lim

But thanks to Janecka and his colleagues, we’re now confident of this: Colugos are primates’ closest living relatives. So although “flying lemur” is a misnomer, both because colugos aren’t flying but gliding and they’re not a kind of lemur, the name isn’t that far off.

“Because they have these adaptations for gliding, originally people sort of threw them in with bats,” Janecka said. “But when they looked at the actual morphology of the skull, there was evidence that they’re closely related to primates.” When Janecka and his colleagues did a genomic analysis of the colugo, this suspicion was confirmed. It turns out that around 90 million years ago, at the height of the dinosaurs’ reign when mammals were just tiny furballs scurrying about trying not to get stepped on, the colugo’s ancestors split off from our primate lineage. Some 25 million years later, the dinosaurs’ time came to an end, leading to the explosion of mammalian diversity.

In fairness, though, it’s the arthropods and bacteria who really rule the world, not us mammals. But they can’t do cool things like glide 200 feet or comb themselves with their teeth…or drop poop that moves on its own.

So there’s that.

The US Is Stockpiling Ebola Survivors’ Plasma to Treat Future Patients

 Getty Images

Emory University Hospital will begin stockpiling blood plasma from Ebola survivors, treated with a pathogen inactivation system that’s never been used before in the United States, the company that developed the technology announced on Friday. So far, the US has had some amazing success in curing Ebola, possibly thanks to experimental plasma treatments. Drawn from survivors, the stuff comes enriched in antibodies that could help to fight off the disease—but it also has the potential to carry other diseases, like malaria, that are common in west Africa where Ebola is raging. The new system will kill off any extra contaminants that may be lurking in this potentially live-saving serum.

It’s the same one, Cerus Corporation’s Intercept system, that will be used in a Gates Foundation-funded study of Ebola treatments in West Africa. The pathogen-killing molecule at the heart of the system is amotosalen, part of a class of three-ringed molecules called psoralens. They’re the compounds in lime that cause what some doctors call “Mexican beer dermatitis”: Get a squirt of the citrus on your skin when you push it into your Corona, spend a few hours on the beach in the sunlight, and the molecules interact with the UV rays to give you a nasty rash.

Cerus’ Intercept system activates a molecule with UV light to destroy genetic material in pathogens.  Cerus Corporation

Amotosalen doesn’t cause dermatitis, but it works by the same mechanism. When technicians add it to blood plasma, it nestles in the middle of DNA and RNA helices, linking the bases on either side. Then, activated by a burst of UV light, it irreversibly bonds to those bases—so the genetic material can’t replicate any more. Pathogens, inactivated.

Europe has long used blood purification systems—Intercept was first approved eight years ago, and there are other techniques, too. But the FDA has been slow to approve the same technology in the US, mostly, it seems, for lack of demand. Last week the agency approved the technique for restricted use in treating the plasma of Ebola survivors.

We already screen donated blood for several common contaminants: infectious diseases like hepatitis, West Nile, and Chagas disease. (The Red Cross also screens for HIV, but unfortunately the FDA still prohibits gay men from donating blood.) Those screens mean it’s very safe to use donated blood in the United States. But that can change when new diseases enter the pipeline—ones that we don’t test for, or ones that we don’t even know exist.

For the FDA, the tipping point might have been two diseases that are new to the US, Chikungunya and dengue. As temperatures rise, mosquitoes migrate northwards, carrying diseases that have historically been stuck in warmer, tropical countries. So in October, the FDA approved the Intercept system for use in areas like Florida and Texas where the mosquito-borne diseases are becoming a problem. (Nobody’s used the treated plasma yet.) Because they’re so uncommon here, we don’t test for those two diseases, or malaria. But soon, testing may not be enough.

“There’s an increasing realization that it’s challenging to be proactive about epidemics with our current testing paradigm,” said William ‘Obi’ Greenman, Cerus’ president and chief executive officer. We may be confronting enough new pathogens in this rapidly changing climate of ours that inactivation will become necessary to keep our blood supply safe. If so, the FDA is ready; Greenman says they’re likely to decide whether to approve the Intercept system to treat all donated plasma in the next several months.

Can the Internet Count Coins as Well as a Bank Machine?

The Steiner’s coin jar.  Susie Steiner

Small change is ridiculous. Still, we keep it around, in part as a reminder of simpler times, in part because the zinc lobby assures us that we need pennies and nickels, and in part because now and then we really do need pennies and nickels. (How else would we adjust this furniture set or make all of this?)

Most of us, though, don’t put coins to such creative use. We either lose them under car seats or toss them in a jar to be forgotten. One such jar recently got Stanford researcher Erik Steiner thinking about money and, more so, the wisdom of crowds.

So, he decided to run an experiment that includes a crowdfunded prize. Here is the backstory as he told it to me earlier this month:
 

In 1987, my parents inherited a piggy bank–a big glass jar–with a few coins in it. Over the last 27 years, they’ve tossed in their spare change, almost daily. Gradually, they built up a pretty sizable sum, or so it looked. But last week my 66-year-old mother decided it was time to cash in.

Using six 15-pound canvas bags, she brought the coins to Fulton Bank in State College Pennsylvania (the only bank she could find that wouldn’t take a cut). A bank employee emptied the bags into a giant money-counting machine that chugged and groaned, spit out a few Canadian pennies, and then came to a screeching halt. The operator opened it up, revealing a secret: the money is weighed, not counted. Blasphemy! Once it was fixed and my mom received equivalent value in paper money, she left the bank questioning whether she and my dad had gotten their money’s worth.

She had also recently been reading about the “wisdom of the crowd.” If she had asked people to guess the value of the money in the jar, would a person–or all people–be able to produce an equally accurate estimate? It apparently works with jelly beans, so why wouldn’t it work for loose change?

Because everybody loves a bean guessing contest, and because I work at a lab where we have done some crowdsourcing research, we decided to put my mom’s question to the masses. The questions are part trivial (How much did my parents pocket in the end?), part societal (Does saving small change make a difference?), and part theoretical (How wise are crowds? Do we over- or underestimate valuable things?).

 
If a massive crowd converges on a number, how close will it be to the machine at the Fulton Bank? We’re excited to find out.

Make your guesses by Dec. 8. After the results are in, Steiner is going to produce some kind of visualization to showcase the results. Maybe he should crowdsource that, too!

What’s Next for the Rosetta Mission and Comet Exploration

This mosaic of comet 67P/Churyumov-Gerasimenko contains four images taken by Rosetta’s NAVCAM navigational cameras  ESA/Rosetta/NAVCAM

Somewhere dark and icy on a comet 320 million miles away, the history-making, comet-bouncing Philae spacecraft is sleeping. Its batteries are depleted and there isn’t enough sunlight to recharge. But while the lander finished its primary job, collecting invaluable data on the surface of comet 67P/Churyumov-Gerasimenko, the Rosetta mission is far from over. For many scientists, the excitement is just beginning.

Read More:

Incredible New Photos Taken From the Surface of a Comet

This Is What It Sounded Like When We Landed on a Comet

Philae’s landing two weeks ago was a wild one. The washing-machine sized spacecraft dropped right onto its intended landing site, but the harpoons designed to anchor it into the ground didn’t fire. Without anything to latch onto the surface, the spacecraft bounced back up a kilometer into space, soaring for nearly two hours before returning to the ground. After another smaller bounce, Philae settled somewhere in the shadow of a cliff, at least 1 kilometer from where it was supposed to be.

Mission engineers are now scouring the comet for signs of the lander. They’re using the OSIRIS camera onboard the Rosetta spacecraft that’s orbiting the comet to look for any glint of brightness reflected by Philae, says planetary scientist Sebastien Besse, a member of the OSIRIS team. They’re also using data from the CONSERT instruments on Rosetta and Philae, which send radio signals between the two spacecraft, to triangulate the lander’s location.

November 17, 2014: Watching Philae Drift ESA/Rosetta/MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Once they find Philae, mission engineers can better assess the chances that it will eventually receive enough sunlight to recharge, wake up, and do more science. “The chances seem reasonably good,” said Mike A’Hearn, a planetary scientist from the University of Maryland and a member of the Rosetta science team. So far, the team has narrowed down Philae’s location to a sliver about 100 feet wide and 1,150 feet long near a depression on the south side of the comet, where it’s now winter.

But summer is coming. Over the next few months, the changing seasons will bring more direct sunlight onto Philae. The comet is also moving toward the sun, and the hope is that in the next few months, both the coming summer and increasing proximity to the sun will give Philae the warmth and power it needs to wake up. Mission controllers have done everything possible to give Philae a chance, Besse says. Before Philae shut down, they rotated the lander 35 degrees to orient its solar panels toward the sun.

For now, all we can do is wait. “I’m very confident that Philae will resume contact with us and that we will be able to operate instruments again,” said lander team leader Stephan Ulamec in a statement on Nov. 17.

Of course, there’s a lot of uncertainty, and Philae will need quite a bit of luck, Besse says. Still, the team is hopeful. “In this business, you have to be optimistic,” he said.

An illustration of Philae is overlaid on top of a panoramic photo from the surface of the comet. ESA/Rosetta/Philae/CIVA

Preliminary Results

Despite the unexpected triple landing and its current MIA status, Philae did the science it was supposed to do. It ran its preprogrammed sequence of commands and started collecting data with its suite of instruments, sniffing, hammering, drilling, and even listening to the comet. Powered by only 60 hours of battery life and with its ability to recharge in doubt, Philae beat the clock and sent all the data back to Earth before its battery petered out.

Scientists are still busy analyzing the bounty of data, but they’ve already released some preliminary results. Philae has detected organic molecules, which are necessary for life. One of the reasons scientists want to study comets is that the icy bodies could have delivered the organics and complex molecules needed for life when they slammed into the planet early in its history.

Past comet missions and ground-based telescopes have seen dozens of molecules on comets, including organics. For example, this summer, the Atacama Large Millimeter/submillimeter Array telescope in Chile found organic molecules in the atmosphere of comets ISON and Lemmon. But what kind of molecules did Philae detect? That remains to be seen.

One instrument enabled Philae to hammer into the ground and find that the surface underneath the lander is surprisingly hard, likely made of ice. Philae also measured vibrations created when the feet of the lander hit the ground on the first landing, producing the first-ever audio recording of a comet touchdown. An analysis of the recording suggests a layer of soft dust sits on top of the hard, icy surface.

The lander was also supposed to drill into the comet and deliver samples into its ovens, which would analyze the chemical composition of samples. Both the drill and the ovens worked perfectly, but it’s unclear whether Philae was able to drill anything at all. The team is still analyzing the data to see what, if anything, the ovens measured. Initial indications don’t look good, however. According to a tweet on Nov. 17 from Science magazine’s Eric Hand, Fred Goesmann of the Max Planck Institute for Solar System Research and leader of the COSAC instrument said that the drill didn’t deliver any samples into the ovens. “There’s nothing in it,” Goesmann was quoted as saying.

Indeed, the botched landing did compromise some of the science. For instance, accelerometers and thermometers on the harpoons never deployed, so couldn’t gather any data. “It’s unfortunate the lander didn’t do exactly what it was supposed to do,” said planetary scientist Anita Cochran of the University of Texas at Austin, who is not a part of the Rosetta mission. Still, she says, Philae got loads of important information. “Whatever they get is way more than we had,” she said.

Watching a Changing Comet

In the days surrounding Philae’s landing, the Rosetta spacecraft collected scientific data from afar. Much of those results have been submitted into scientific journals and will likely be published in the next couple weeks, Besse says. But Rosetta’s main job has been to support Philae, scouting out possible landing sites, and watching over the lander as it settled onto the comet. Now, the real science begins for Rosetta.

As part of a maneuver to adjust its orbit, the spacecraft will fire its thrusters to lift it to 19 miles from the comet. On Dec. 3, it will move closer until it’s 12.5 miles away. Rosetta will remain in orbit, watching the comet come to life as it approaches the sun, reaching its closest point in mid-August. The ices on the comet will heat up, sublimating into gases that are ejected into space. The rubber-duck-shaped chunk of ice and dust will be enshrouded in a haze of dust and gas called the coma. The sunlight will push the dust and gases away and form the comet’s tail.

And Rosetta will be right there watching the action.

November 13, 2014: Welcome to a Comet!  ESA/Rosetta/Philae/CIVA

Previously, spacecraft have visited seven different comets, but nearly all missions were quick flybys. In 2005, the Deep Impact mission fired an impactor into comet Tempel 1, blasting a cloud of debris that could then be analyzed. The Stardust spacecraft, which went to comet Wild 2 in 1999 and grabbed a sample of its tail to return to Earth, swung by comet Tempel 1 in 2011 for a closer look at the crater created by Deep Impact.

All these missions studied a comet at a single point in time, capturing just a snapshot. But comets are dynamic objects; their characteristics are defined by change. They suddenly appear in the sky, growing brighter and brighter, its tail stretching longer and longer. Then, just as sudden as they appeared, they shrink and fade. Now, for the first time, Rosetta will be able to observe what is actually happening on the comet up close.

For example, Rosetta will be able to see how exactly dust and gas escapes the comet and how this varies from place to place, says A’Hearn. In doing so, scientists can distinguish features that are due to the comet’s evolution over time from primordial features that were a part of the comet since its formation. Pinpointing those properties, A’Hearn says, is essential for understanding how comets form, the history of the solar system, and whether comets could have delivered the chemicals needed for life on Earth.

NASA’s EPOXI mission took this picture of comet Hartley 2 from a distance of about 435 miles. You can see jets streaming out from the comet.  NASA/JPL-Caltech/UMD

Rosetta will also probe the interior of the comet, mapping the different layers of ice and dust and how its density varies. Another question, Cochran says, is how comet 67P’s shape will change over time. Will the neck connecting the two lobes whittle away? Will the comet eventually split apart? Is the comet the result of two pieces that stuck together?

Rosetta’s mission will continue until December 2015, following comet 67P as it swings back away from the sun. The hope is that the spacecraft will keep working deep into 2016. But that will depend on the unpredictable volatility of the comet, Besse says. Dust particles expelled by the comet could damage the spacecraft. The comet could belch out gas that blows Rosetta off course. Or, Rosetta could just wear down. It is, after all, already 10 years old. In that time, many of us have already gone through several computers and phones. But so far, Besse says, Rosetta seems to be in great shape.

Future Missions

So we’ve landed on a comet. And we’re now orbiting one for the first time. What’s next? Scientists are already planning future comet missions, which most likely will involve another lander at the very least. One idea is for a spacecraft to hop from place to place on a comet—this time, on purpose—and study differences on the surface. One such proposed mission, the Comet Hopper, made it to the final rounds of NASA’s selection process in 2012 before losing out to a Mars lander called InSight, which is slated for launch in 2016.

Missions like Comet Hopper and Deep Impact were NASA Discovery missions, which are intended to be faster and cheaper projects. For the next Discovery mission, there are at least three proposals for sending a spacecraft to a comet, says A’Hearn, who led the Deep Impact mission and was a part of the Comet Hopper proposal.

This image of comet Tempel 1 was taken 67 seconds after it was hit by Deep Impact’s impacter. NASA/JPL-Caltech/UMD

But what comet scientists would really want is a sample return mission: Send a spacecraft that could grab a chunk of comet and send it back to Earth. The kinds of experiments you can do in Earth-bound labs are much more sophisticated than anything onboard a spacecraft, Cochran says. But such a mission would be difficult and expensive. For example, Besse adds, you would have to build a cryogenic capsule to keep your comet stuff cold. And comets are cold. In August, Rosetta measured comet 67P’s average temperature to be -94 degrees Fahrenheit.

Because of the added complexity and expense, a sample return mission would have to be one of NASA’s higher-cost New Frontiers missions. One of those missions, New Horizons, will begin exploring Pluto and its moons in 2015. Another, Juno, will arrive at Jupiter in 2016. “I expect that there will be at least two separate proposals for a comet surface sample return mission in the next round of New Frontiers,” A’Hearn said. These future missions will be needed, he says. Rosetta will answer many questions about comets, but it will also raise many more.

Until then, Rosetta has center stage. And the show is about to begin.