Christie's

Francis Crick sketched this diagram of the DNA double-helix molecule in a 1953 letter to his son, Michael. "The model looks much nicer than this," the elder Crick wrote.

The modern era of biology was launched 60 years ago today with the publication of a one-page paper in the journal Nature that described the DNA's double helix structure, a revelation of how organisms store biological information and pass it from one generation to the next.

The Nobel Prize winning discovery was published by the biologists James Watson, an American, and Francis Crick, an Englishman. In 2003, Congress declared that "DNA Day" was April 25.

The date is also special because it commemorates the completion of the Human Genome Project — the reference sequence for the 3 billion DNA letters that comprise the human genome — the instruction book for building and maintaining a human being, Francis Collins, director of the National Institutes of Health, notes in a blog post today.

To learn more about the day and the discoveries it celebrates, check out the National Human Genome Research Institute's DNA Day Facebook page. Visitors are encouraged to suggest a "DNAnalogy" that helps explain what DNA is. For example, visitor Tom Wood writes that "DNA is like an architectural blueprint. The blueprint is the plan, but it's never the final result."

The weeks leading up to this year's celebration of the 1953 discovery have been filled with stories about a 60-year-old letter in which biologist Francis Crick told his son about DNA's double helix structure. The letter and Crick's Nobel Prize sold at an auction on April 10 for a record $6 million. 

To learn more about the DNA, check out the stories below:

• New Nobel letters reveal secrets of DNA prize
• Nobel Prize medal for discovery of DNA structure to be sold
• Lessons learned as human genome map turns 10
• Human Genome Project marks 10 years

John Roach is a contributing writer for NBC News. To learn more about him, visit his website.

Wildlife Conservation Society

The promise and peril of synthetic biology for wildlife conservation and biodiversity will be the subject of an international conference in England this month.

Conservationists say it's high time to consider whether synthetic biology will solve some of the huge problems that beset endangered species, or bring new problems. It just might do both.

"Synthetic biology brings with it a powerful attraction, causing biology to veer towards engineering with its inherent approach of human problem solving," three experts on biodiversity and conservation say in this week's issue of PLOS Biology. "It may prove to be a cure for certain wicked problems. But we suggest that now is the time to consider whether synthetic biology may be a wicked solution, creating problems of its own, some of which may be undesirable or even unacceptable in the area of biodiversity conservation."

The PLOS Biology essay was written by Kent Redford of Archipelago Consulting, William Adams of the University of Cambridge, and Georgina Mace of University College London's Center for Biodiversity and Environment Research. The three conservationists are the organizers of a conference on synthetic biology, due to take place next week in Cambridge, England.

What is synthetic biology?
Synthetic biology takes advantage of genetic engineering to tweak existing organisms for new purposes — for example, strains of E. coli bacteria that live on coffee, or produce better biofuels.

More recently, researchers have talked about reshaping the genome of one species so that it reflects the traits of a closely related extinct or disappearing species — such as the American chestnut, the passenger pigeon, the Tasmanian thylacine or the Siberian woolly mammoth. Last month, that kind of de-extinction was discussed during a widely watched conference in Washington.

This month's conference takes a closer look at the scientific and ethical issues relating to conservation. Would de-extinction truly bring back the species that were wiped out, or will they actually be novel species, even alien species? How will revived species interact with the other species that have taken their place? Will we actually value the "natural" world less, because we assume de-extinction can bring back our favorites? What happens if synthetic life evolves in unforeseen ways? What's the implication of having patented life forms in the wild?

"A serious need exists for wider discussion of the relationship between synthetic biology and biodiversity conservation, and what choices society can and should make," the three experts say. But that poses a huge challenge, because many people haven't even heard of synthetic biology yet.

Plateau in awareness
The latest in a series of surveys conducted for the Synthetic Biology Project at the Woodrow Wilson International Center for Scholars suggests that public awareness about the issue is plateauing. Forty-five percent of those surveyed said that they had heard nothing at all about synthetic biology, which is about the same level of non-awareness found during the center's previous survey in 2010.

Lack of public awareness makes it difficult to conduct a wide-ranging debate over a technology's pros and cons, said Eleonore Pauwels, a research associate at the Wilson Center. "It is still at the stage of hype, and promises, and new funding coming in," she told NBC News. "When you don't have a lot of information, you only have the buzz or the hype."

The survey also found that 61 percent supported continuing research in synthetic biology, while 34 percent wanted such research banned until its implications and risks were better understood. "The more information you give to people, the more questions they're going to ask, and the debate becomes more complex," Pauwels said.

The situation is likely to change once synthetic-biology applications actually start hitting the market. Among the first applications are methods to produce flavors such as vanilla and saffron using genetically modified microbes. Another high-profile example is a project that uses genetically engineered yeast to produce artemisinic acid, the key ingredient for an anti-malaria drug.

"If they get the antimalarial drug out of clinical trial soon, it's going to refuel the interest in synthetic biology as a new way of manufacturing drugs," Pauwels said.

What about manufacturing mammoths? Is synthetic biology a technology whose time has come? Or should experiments on the bleeding edge of genetic engineering be put on hold for a while, as they were in the 1970s? Feel free to cast your vote in our unscientific survey, and voice your opinion in the comment space below.

More about synthetic biology:

• How synthetic biology will change us
• What to do about synthetic life?
• Cosmic Log archive on synthetic biology

The Wilson Center's 2013 nationwide telephone survey on awareness and impressions of synthetic biology was conducted by Hart Research Associates from Jan. 10 to 14. Hart Research surveyed 804 adults, including 243 who use only a cell phone. At the 95 percent confidence level, the data's margin of error is plus or minus 3.5 percentage points.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

The ASSET Program / Cornell

An image produced by a scanning electron microscope shows two Tetrahymena cells in the act of mating.

Biologists have known for decades that there are up to seven sexes of the single-celled organism known as Tetrahymena thermophila — but they didn't know exactly how those different sexes "did it." Until now.

When it's time for Tetrahymena to mate, two organisms of different mating types recognize each other and get together to swap DNA. The results of the hookup are totally random. One critter may be mating type No. 1, the other may be mating type No. 3, and the two resulting progeny may turn out to be, um, mating type No. 6. How do they do that?

In the journal PLOS Biology, researchers report that the hooked-up organisms almost literally roll the genetic dice to determine what the sex of the progeny will be.

The researchers say the key to Tetrahymena's sexual proclivities lies in its double genome: Every cell has a "somatic" genome that manages its everyday life, plus a "germline" genome that serves a function similar to that of the ovaries or testes in humans. The germline genome contains incomplete gene pairs for each of six or seven sexes, depending on the cell line. (In this case, the cells came in six sexual flavors.)

Random sex
When two microbes hook up, the progeny's newly created somatic genome latches onto one of those incomplete gene pairs, producing one complete sex-specific gene pair. The other sexy bits from the germline genome are wiped out. The random rearrangement leaves the resulting cells with exactly one complete sex-specific gene pair — and one mating type.

"It's completely random, as if they had a roulette wheel with six numbers, and wherever the marble ends up is what they get," senior researcher Eduardo Orias, a research professor emeritus at the University of California at Santa Barbara, explained in a news release. "By chance they may have the same mating type as the parents — but it's only by chance. It's a fascinating system."

Most of the time, Tetrahymena reproduces asexually, simply by having a parent cell divide into two progeny cells. But the organisms tend to pair up sexually when food is scarce, apparently as part of an evolutionary mechanism that takes advantage of genetic diversity. Sex-specific proteins on the surface of the cells serve as a signal that mating is likely to result in more diverse progeny. That's how two cells of the same mating type avoid pairing up with each other.

This type of mating process doesn't by itself increase the Tetrahymena population: Two cells hook up, and after recombining DNA, two cells separate again. "This is sex without reproduction," Orias said during a telephone interview. After mating, the recombined genetic information is passed down from parents to progeny through asexual reproduction — until it's time for the next hookup.

What it means for humans
Although the process sounds totally alien to us two-sex types, the lessons from Tetrahymena could have implications for human health.

"Tetrahymena has about as many genes as the human genome," Orias said in the news release. "For thousands of those genes, you can recognize the sequence similarity to corresponding genes in the human genome with the same biological function. That's what makes it a valuable organism to investigate important biological questions."

For example, Tetrahymena may reveal new tricks relating to the methods that cells use to recognize friend vs. foe. That could have implications for studying human immune response. Also, the way that the organisms rearrange their DNA may point to new strategies for fighting cancer, which often results from the faulty rearrangement of genetic material.

"The hope is that at some point, there may be useful applications for medicine," Orias told NBC News.

More about microbial marvels:

• No sex for 40 million years? No problem!
• Single-celled giant upends early evolution
• Strange organism has unique roots in tree of life

In addition to Orias, the authors of "Selecting One of Several Mating Types Through Gene Segment Joining and Deletion in Tetrahymena Thermophila" include Marcella D. Cervantes, Eileen P. Hamilton, Jie Xiong, Michael J. Lawson, Dongxia Yuan, Michalis Hadjitomas and Wei Miao.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Shawn Heinrichs for Pew Environment Group

Shark fins dry in the sun in the Taiwanese city of Kaohsiung before processing. Thirty percent of the world's shark species are threatened or near threatened with extinction.

By Megan Gannon
LiveScience

Aggressive overfishing threatens to push some shark species to extinction, and a new study puts annual shark deaths at 100 million.

"Our analysis shows that about one in 15 sharks gets killed by fisheries every year," study leader Boris Worm, a professor of biology at Canada's Dalhousie University, said in a statement. "With an increasing demand for their fins, sharks are more vulnerable today than ever before."

Based on available data for shark deaths and estimates of unreported illegal catches, the researchers estimated that 100 million sharks were killed in 2000 and 97 million in 2010. But since scientists lack sufficient data on shark catches, they say the real number of annual shark deaths could possibly be between 63 million and 273 million. 

Sharks are fished for their meat, liver oil, cartilage and valuable fins, which are hacked off, often from live sharks, to be used in shark fin soup, an ancient and prized delicacy in East Asia. Since sharks have slow growth and reproductive rates, it can be tough for their populations to bounce back from big losses.

Conservationists say the depletion of shark populations is concerning because as apex predators, they help balance ecosystems in the world's oceans. [On the Brink: A Gallery of Wild Sharks]

"In working with tiger sharks, we've seen that if we don't have enough of these predators around, it causes cascading changes in the ecosystem, that trickle all the way down to marine plants," said study researcher Mike Heithaus, a Florida International University biologist.

On March 3, hundreds of delegates from 177 different countries will descend on Bangkok for the meeting of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, or CITES. On the agenda will be increased trade protection for five species of sharks — the oceanic whitetip, porbeagle and three types of hammerheads — which are hunted for their fins.

"A simple vote 'yes' to support their listing could turn things around for some of the world's most threatened shark species," Elizabeth Wilson, manager of global shark conservation at the Pew Charitable Trusts' environmental organization, said in a statement. "Countries should seize this opportunity to protect these top predators from extinction."

Sharks have a PR problem that might be hurting their chances of survival. A study out last year found that a majority of the media coverage they get involves shark attacks on humans, which doesn't reflect how rare these scary encounters are. In 2012, there were 80 confirmed shark attacks worldwide, but only seven of them were deadly, according to the University of Florida's International Shark Attack File.

The new research was detailed online in the journal Marine Policy.

Follow LiveScience on Twitter @livescience. We're also on Facebook & Google+. 

• Image Gallery: Great White Sharks
• Cyclops of the Sea: Pictures of a One-Eyed Shark
• In Photos: Top 10 Deadliest Animals

© 2013 LiveScience.com. All rights reserved. 

Dognition

Duke neuroscientist Brian Hare tests a dog's cognition using a simple set of toys.

Is your dog an Einstein or a Charmer? For $60 (woof!!), a new business venture called Dognition will help you put your pooch through a series of fun playtime activities to find out how your dog thinks. The metrics generated by those experiments … I mean, fun playtime activities … are being fed into a research project that could for the first time determine how the cognitive traits of various breeds differ.

"Dognition.com is ultimately about people's dogs, and finding out about your dog," Duke University neuroscientist Brian Hare, one of the venture's co-founders, told NBC News. "That's what you're paying for. I buy fancy dog food for my dog, and just like I want to take care of his stomach, I want to take care of his mind, too. Skip the next couple of chew toys, and your dog and you will really enjoy doing something a little different."

The business venture builds on Hare's work as the director of the Duke Canine Cognition Center and an associate professor in evolutionary anthropology at Duke's Center for Cognitive Neuroscience. It also meshes with a newly published book by Hare and his wife, Vanessa Woods, titled "The Genius of Dogs."

How smart are dogs?
Don't expect Dognition's cognitive assessment to measure your pet's IQ: Hare says a dog's intelligence can't be described with a single number. (Come to think of it, the same caveat should apply to humans.)

"Because we use standardized testing in all walks of life, it leads you to believe that there's just one measure of intelligence, and there's a number, and that's it," Hare said. "But when you start studying cognitive science, and look at other species, that all starts to crumble."

It's also fruitless to try calculating whether dogs are smarter than cats, or chimps, or bonobos. "That's like trying to answer the question, 'Is a hammer better than a screwdriver?'" Hare said. Instead, he and his colleagues look at how dogs and other species address problem-solving challenges and communicate with humans. It turns out that dogs are geniuses when it comes to figuring out what humans are trying to tell them — which suggests that our world is truly going to the dogs.

"Dogs are bizarrely successful," Hare said. "They have more jobs than ever in this age of the Internet and the International Space Station."

Researchers have even argued that humans and dogs are locked in a co-evolutionary embrace that began tens of thousands of years ago. Last month, for example, one research team determined that canine digestive systems have adapted to the relatively starchy diet served up by modern humans.

How it works
Hare's research into dog cognition began back in 1995, with studies of how dogs looked for hidden treats when humans tried giving them hints. Those experiments, which are done using simple household items such as plastic cups (plus tons of treats), are laid out in Dognition's Canine Assessment Toolkit.

After you plunk your money down, Dognition's website takes you through a personality questionnaire about your dog: For example, how excited does your dog get around other dogs, grown-ups, children? Do fireworks scare your pup? Then, Dognition guides you through a battery of tests that are as fun as playing fetch, or hide-and-seek. The results are uploaded to Dognition HQ, and you get back a detailed profile of your dog's mental habits, based on where Fido's performance ends up on a chart of independent vs. social problem-solving skills.

Different areas of the chart are associated with nine different canine archetypes: Ace, Stargazer, Maverick, Charmer, Socialite, Protodog, Einstein, Expert or Renaissance Dog. That can give you something to brag about on Dognition's Facebook page, but it also can shed new light on why dogs do the things they do, or how you can get through to them better. "We've got a bunch of really fantastic trainers who have signed up to help," Hare said.

Researchers get a reward as well: The data from hundreds of Canine Assessment Tests can be correlated with breed, age and other factors. "To collect the amount of data we've taken in during our month-long beta program would have taken us a couple of years," Hare said.

Eventually, Hare and his colleagues hope to map out the substantive cognitive differences between dog breeds — differences that have not yet been studied scientifically. "The reason we don't know anything about breed differences is that we currently don't have the tools available to look at the number of dogs that would allow us to answer the interesting questions," Hare said.

Dognition could fix that. And it also could open up new possibilities for some of humanity's best friends.

"One of the things we're hoping to do is, suppose there's that dog that may not be the most attractive dog physically, but the dog is wonderfully behaved," Hare said. "What Dognition.com can do is help people understand more about what's inside that dog, and not just its physical appearance — and see that, wow, this dog is amazing."

More about dog intelligence:

• Dog's vocabulary makes her a star
• Gallery: Cat vs. dog intelligence
• The world's 10 most intelligent animals
• How smart is your dog? Give him an IQ test

Dognition offers a $59.95 Canine Assessment Toolkit as well as a $129.95 annual membership bundle that includes enhanced games and other goodies.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

WISSARD Project via Antarctic Sun

A laptop screen shows a video view of the borehole drilled through Antarctica's ice down to Lake Whillans.

The first signs of potentially exotic life have been spotted in a sample of water drawn from Antarctica's hidden Lake Whillans, a half-mile beneath the surface, according to reports from the scene.

The telltale green glow of cells stained with a DNA-sensitive dye could be seen when water from the lake was put under the microscope on Monday, Discover Magazine's Crux blog reported. "It was the first evidence of life in an Antarctic subglacial lake," science journalist Douglas Fox reported for The Crux. Fox is an embedded journalist reporting from Lake Whillans under the auspices of a National Science Foundation program.

The U.S. scientists in charge of the project to drill into Lake Whillans — known as the Whillans Ice Stream Subglacial Access Research Drilling, or WISSARD — will be more circumspect: They'll have to demonstrate that the green-glowing cells are truly alive and capable of growing in culture. They'll also conduct tests to make sure that the microbes are indigenous to the lake, rather than the result of contamination from the drilling operation.

Last year, Russian scientists analyzed water from Lake Vostok, an even deeper and bigger subglacial lake beneath Antarctica's Vostok Station, but the only microbes they found in the sample were surface-dwelling species that may have come from contaminated drilling chemicals rather than the lake itself.

During the current Antarctic research season, the Russians resumed their drilling at Vostok. They said earlier this month that they had reached transparent lake ice at a depth of 3.4 kilometers (2.1 miles). Since then, they've reported retrieving "fresh frozen" ice cores from slightly deeper levels.

The Russian and U.S. teams are drilling into the lakes in hopes of finding evidence of life forms that could have been living in the dark for thousands of years, or even millions of years. Theoretically, such organisms could live off the minerals in deep-buried rock, plus oxygen dissolved in the lake water.

The Whillans Ice Stream is a glacial river that pushes ice from the West Antarctic Ice Sheet into the Ross Ice Shelf. Lake Whillans lies about 800 meters (0.5 miles) beneath the ice, less than 400 miles (640 kilometers) from the South Pole. Just this past weekend, the WISSARD team reported that their borehole connected with the lake after several days of drilling. 

Fox quoted scientists as saying that Lake Whillans is just 5 to 6 feet (1.5 to 2 meters) deep, as opposed to the 20 to 30 feet (6 to 9 meters) that was expected. The first water samples that were brought up contained the ancient fossils of dead diatoms — tiny marine creatures that are thought to have been pushed down into the lake from West Antarctica.

The study of Lake Whillans and other subglacial lakes should shed light on Antarctica's climate history, as well as the long-term interaction between the continent's ice and the water and rocks that lie beneath. The discovery of novel life forms could open up an entirely new frontier for biologists. And even if the organisms found in the lakes aren't all that unusual, the drilling operations could set the stage for future missions to the ice-covered moons of Jupiter and Saturn, where similarly challenging conditions for subsurface life are thought to exist.

More about the mysteries beneath the ice:

• Saturnian moon Enceladus eyed for sample return mission
• Underground ocean goes deep on Jovian moon Europa
• Mission to drill into Antarctica's Lake Ellsworth suspended

For more about the WISSARD project at Lake Whillans, check out this report from The Antarctic Sun.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Dacke et al. / Current Biology

You might expect dung beetles to keep their "noses to the ground," but they are actually incredibly attuned to the sky. A report published in Current Biology shows that even on the darkest of nights, African ball-rolling insects are guided by the soft glow of the Milky Way.

When dung beetles roll their tiny balls of poop across the sands of South Africa on a moonless night, they look to the glow of our Milky Way galaxy as a navigational aid, researchers report.

"Even on clear, moonless nights, many dung beetles still manage to orientate along straight paths," Marie Dacke, a biologist at Sweden's Lund University, said in a news release. "This led us to suspect that the beetles exploit the starry sky for orientation — a feat that had, to our knowledge, never before been demonstrated in an insect."

That's an amazing claim. But what's just as amazing are the lengths to which the researchers went to make their case.

First, they built a 10-foot-wide (3-meter-wide) circular arena in a South African game reserve and watched what troops of nocturnal dung beetles did on moonlit nights, moonless nights and cloudy nights. They fitted the bugs with little cardboard caps to block their view of the sky. They even fitted some of the bugs with transparent plastic caps, just to make sure that any differences they saw were due to the sky blockage rather than the presence of the caps.

Then the scientists took their dung-beetle arena into the Johannesburg Planetarium and ran the same experiment, to eliminate the possibility that the beetles were using terrestrial landmarks to plot their course in the dark. The planetarium was programmed to show the night sky with the Milky Way, or the Milky Way without the brightest stars in the sky, or the brightest stars without the Milky Way, or just the diffuse glow of the Milky Way with no stars at all.

The bottom line was clear: Those bugs could keep track of how the fuzzy streak of the Milky Way was oriented in the sky, to make sure they rolled their balls of dung in a suitably straight line.

Why is that so important? Without the proper orientation, the beetles might circle back to the dung pile, where they'd have to face all the other beetles trying to steal away their tiny balls of poop. That would put the bugs' intended meal at risk. "The dung beetles don't care which direction they're going in; they just need to get away from the bun fight at the poo pile," Marcus Byrne of South Africa's University of the Witwatersrand explained in a news release.

Marcus Byrne

Dung beetles were fitted with tiny cardboard caps to see how well they could navigate when the night sky was blocked out. When they were wearing the caps, the bugs were more prone to go around in circles.

Dacke, Byrne and their colleagues describe their latest dung-beetle adventure in this week's issue of Current Biology. Researchers have previously chronicled the bugs' other peculiarities: how the insects do a "dance" on top of their dung balls to get themselves oriented (and keep cool as well) ... how they monitor the sun and the moon for poop-ball navigation ... and how they discriminate between different flavors of dung (the smellier, the better).

Byrne said the idea of checking the bugs' celestial compass came up during an earlier series of South African experiments with the bugs. "We were sitting out in Vryburg, and the Milky Way was this massive light source," he recalled. "We thought, they have to be able to use this — they just have to!"

The latest experiments show that for the nocturnal beetles (Scarabaeus satyrus), the moon is the most reliable guide. It took about 20 seconds, on average, for the bugs to make their way out of the arena under moonlit conditions. On a moonless, starry night, it took about 40 seconds. But it took three times as long on a cloudy night, or when the bugs were wearing those cardboard caps. The planetarium tests came up with similar results: The bugs were quickest when they could look up at the dome and see the full, starry sky (43 seconds), or even the Milky Way's bright, diffuse band without the stars (53 seconds). When the planetarium dome was totally dark, the average time rose to 120 seconds.

Before this study, only birds, humans and seals were known to use the stars for orientation. The compound eyes of a dung beetle may not be all that great — but they're good enough to make out the Milky Way's glowing band in a dark sky.

"This study shows that some insects can use the starry sky for orientation, even though they might not necessarily be able to discriminate the individual stars," the researchers wrote. "In theory, insects could use any large and dense group of bright stars for orientation or nocturnal migration."

Scientists have long suspected that celestial orientation is used by still more species, ranging from moths and spiders to newts and frogs. This latest batch of meticulous experiments with poop-rolling beetles may well point the way to confirming those suspicions.

More beetle mania:

• Meet the world's strongest bug
• Weird beetle's sperm teams up
• Gallery: Eight insects with the 'ick' factor

In addition to Dacke and Byrne, the authors of "Dung Beetles Use the Milky Way for Orientation" include Emily Baird, Clarke H. Scholtz and Eric J. Warrant.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.