Last week, Rob told you how scientists announced that they'd found two Earth-like planets orbiting the star Kepler-62. One of those, Kepler-62e, now ranks as the most Earth-like exoplanet we've ever found. Of course, all of this is relative.

What I like about this chart is that it kind of shows you how "Earth-like" doesn't really mean, "Man, that is totally exactly like Earth." Instead, you should translate it more as, "Welp, this is about the closest to Earth that we've found so far." Even Kepler-62e, as you can see, is much larger than the Earth and Mars. And size matters when it comes to actual habitability. As does density — and we don't know what Kepler-62e is made of yet. It's also worth noting that #2 on this list, the infamous Gleise 581g, is really a planet candidate, rather than a planet. We aren't actually certain it exists, just yet.

Popular Science has a neat little breakdown explaining what life might be like on Kepler-62e, if we could go there. But it's worth keeping the context in mind on these Earth-like planets. Don't pack your bags just yet.

Zigong Dinosaurs World Science & Technology Co.,Ltd. makes, as you can probably guess from the name, animatronic dinosaurs. Which, for some reason, they attempt to sell via spam email marketing. We at BoingBoing have gotten spam like this before, from other manufacturers in the surprisingly robust Chinese animatronic dinosaur industry. What made this particular email stand out to me, though, was the above picture, of an animatronic Glyptodont covered in fur.

Now, I'd seen Glyptodonts before, but the reconstructions that I remember came across more as giant armadillos, as opposed to the huge beaver with a shell on its back that you see here. So I contacted Brian Switek, my favorite dinosaur blogger, to ask him which image of the Glyptodont is the correct one.

His response: They both are.

Glyptodonts — a family of creatures that includes the species Glyptodon — were, in fact, ancient relatives of today's armadillo. Many of them were the size of a Volkswagen Beetle. Like the armadillo, Glyptodonts were mammals. And some of the species really did have hair — including on their shells.

What's really interesting is that this isn't totally out of line with the appearance of some modern armadillos. There are several species of hairy armadillos wandering around the Earth right now. One of them is called the screaming hairy armadillo, in honor of the high-pitched squeals it makes if you try to mess with it. Its fur is sparse and tufty, sticking up from its shell and its legs. But another species — Argentina's pink fairy armadillo — really does look something like the animatronic Glyptodont — a pink shell attached to the back of a white, fuzzy rodent.

It's easy to forget the furry parts of Glyptodonts, though, because when we talk about them we tend to focus on their much-more-impressive armor. Besides the obvious shells, various species also sported bony patches on their exposed skin and some even had spiky clubs at the ends of their tails. All of that made an awful lot of sense for a herbivorous creature that had to live alongside saber-toothed cats.

Of course, those defensive adaptations didn't always work. Last year, Brian Switek wrote about a fossil specimen of the species Glyptotherium that had clearly been ripped apart by a big, hungry predator.

Stored within the American Museum of Natural History’s massive Frick Collection of fossil mammals is the busted-up skull of a juvenile Glyptotherium texanum designated F:AM 95737. Tiny fractures run over the entire skull – damage done after death but before fossilization – but most remarkable are two oblong holes sunk into the frontal bones. These holes were likely made by a large saber-toothed cat (though a jaguar is another possibility), and, as assessed by paleontologists David Gillette and Clayton Ray, the apparent ease with which the predator dispatched its victim suggests that this Glyptotherium was stuck. Rather than a sabercat jumping out from nowhere and biting the glyptodont on the head, they reasoned, “It seems more likely that this juvenile was stranded, perhaps in mud, or was otherwise debilitated, unable to avoid an approaching predator.”

The single, perforated skull represents a lucky catch for a saber-toothed hunter, as well as paleontologists. Traces of predation on glyptodonts are rarely found. Juveniles – in which the armor plating had not fully ossified – may have been more vulnerable than adult glyptodonts, but predation on these animals was probably more common than the small collection of damaged bones suggests. The recent discovery of additional armor accessories hints that some of these shelled mammals were in an arms race with the predators of their time.

Read the rest of Brian Switek's Glyptodont story

Read a Smithsonian article describing various Glyptodont specimens, including several with hair follicles on their shells.

Arizona was home to several species of Glyptodonts. Check out this article from Arizona Geology magazine that describes them particularly well.

This is an artists' rendition of Pegomastax africanus, a 200-million-year-old dinosaur that is the subject of a new peer-reviewed research paper out this week in the journal ZooKeys.

It's a great face, and a fascinating species. Couple of things here that I think are worth highlighting:

First, despite the fang-y teeth Pegomastax africanus is sporting, the scientists who wrote the paper think this animal was actually a vegetarian. Or, at least, mostly a vegetarian. At LiveScience.com, the researchers told journalist Charles Q. Choi that the dinosaur had a parrot-like beak, its fangs weren't positioned well for cutting through meat, and its back teeth look like the kind of chompers plant-eaters use to slice through leaves and roughage. All of which suggest Pegomastax africanus ate more seeds, nuts, and fruit than flank steak.

The other cool thing has to do with when Pegomastax africanus was found. While the paper describing the fossil was published online today, the fossil itself was pulled out of the ground in the 1960s. In fact, the paper's main author — paleontologist Paul C. Sereno — first noticed the neglected fossil in 1983, and only recently got around to examining it more closely. Think of it this way, a successful dig might come out with lots of potentially cool rocks and fossils. The fact is that there are often more artifacts than there is time for one team to closely work with all the artifacts. The researchers who did the digging will focus on the ones that are most interesting to them. The rest get catalogued. Maybe the original researchers come back to them; maybe they don't. Maybe somebody else picks up the catalogued fossils; maybe it takes 50 years for that happen. But what this reminds us is that there are cool things waiting to be discovered in storage ... not just in the ground.

Read the full paper, which puts Pegomastax africanus into context as a member of a family of dinosaurs called heterodontosaurids.

Probably not yet. But it's on the cusp. And part of what makes this entire process really, really interesting is that, by the very nature of this whole experiment, we don't know exactly what will happen when Voyager I does cross that imaginary boundary line. But, as Rebecca Rosen explains on The Atlantic, we do have some pretty good theories.

Some cosmic ray particles enter the heliosphere and we can see them here from Earth. But a slower type has a hard time entering the heliosphere. Last month, the sum of those slower particles, suddenly ticked up about 10 percent, "the fastest increase we've seen," Stone says. But an uptick does not mean Voyager has crossed over, though it does mean we're getting close. When Voyager does finally leave and enter the space "out there where all the particles are," the level will stop rising. The rising itself means that Voyager is not out there, yet. "But," cautions Stone, "we don't know. I mean this is the first time any spacecraft has been there." Since nothing's ever been there before, we don't know what it will look like, which makes it a little hard to recognize "it" at all. "That's the exciting thing," he continues.

This is the most exciting kind of science—the sort where we really don't know the answers and we're on the cusp of learning something truly, wonderously new. Stay tuned.

Read Rebecca Rosen's full article at The Atlantic

As Rob noted earlier today, Space Shuttle Discovery piggybacked in flight this morning to its final resting place, at the National Air and Space Museum's Udvar-Hazy Center. Here is video of the shuttle arriving in Washington, DC.

Space reporter Miles O'Brien was at Kennedy Space Center this morning for the final departure.

NASA has a Flickr pool where folks along the flight path have posted flyover shots. And there are some great "citizen photographer" shots of the DC descent from various POVs here. NASM's own Isabel Lara was wowed at the landing site:

They're incredible up close!!! #SpotheShuttle #OV103 twitter.com/isalara/status…

— Isabel Lara (@isalara) April 17, 2012

It's a bittersweet day for space fans. Private space exploration continues from KSC, with a planned rocket launch from SpaceX later this month. But with Discovery's final journey, a great era in manned space flight truly feels over.

]]> http://boingboing.net/2012/04/17/space-shuttle-discoverys-fin.html/feed 15 http://boingboing.net/2011/12/20/an-easier-to-build-solar-cell.html http://boingboing.net/2011/12/20/an-easier-to-build-solar-cell.html#comments Tue, 20 Dec 2011 22:55:58 +0000 Maggie Koerth-Baker http://boingboing.net/?p=135297

Solar cells are not easy to build, but a new technology from Notre Dame could, someday, change that. It involves a nanoparticle paste made from t-butanol, water, cadmium sulfide and titanium dioxide. Here, you watch the process of constructing a solar cell this way and see why it could be easier and cheaper than current options. The downside: These solar cells won't be coming to a neighborhood near you anytime soon. They're in the early stages of research and are still only 1% efficient at converting solar energy to electricity. (Standard solar cells tend to be closer to 25% efficient.)

Video Link]]> http://boingboing.net/2011/12/20/an-easier-to-build-solar-cell.html/feed 17 http://boingboing.net/2011/11/17/forget-love-biological-sex-is.html http://boingboing.net/2011/11/17/forget-love-biological-sex-is.html#comments Thu, 17 Nov 2011 22:49:18 +0000 Maggie Koerth-Baker http://boingboing.net/?p=130004 Gender isn’t a simple thing. A person can be male, female, both, neither, and more—and that identity doesn’t have to have anything to do with the particular genital plumbing they were born with.

But the plumbing itself—the biological sex, rather than gender or socio-cultural sex—is also a lot more complicated (and interesting) than we often give it credit for. Don’t believe me? Then check out “DMRT1 prevents female reprogramming in the postnatal mammalian testis,” a research letter published in September in the journal Nature.

That title is full of typical peer-reviewed paper jargon, but let me break it down for you: There’s a genetic factor, present in male mammals, that is vital to making sure those mammals develop male sex characteristics. But it’s not only important during embryonic development. Oh, no. Turns out, this factor must be active in order for a male’s gonads to stay 100% male. Turn it off, even in an adult male, and the cells in his testes will start to take on more feminine characteristics.

The genetic factor is called DMRT1, and it is not the only thing responsible for maintaining a mammal’s biological sex throughout life. There’s another factor, called FoxL2, that does the same job in females. Scientists already knew about the lifelong necessity of FoxL2. This new research, performed by a team led by Drs. David Zarkower and Vivian Bardwell of the University of Minnesota, confirmed that DMRT1 is FoxL2’s male counterpart.

It all begins in utero. Mammals—both the mice used in this study, and larger creatures like us—start out effectively sexless, with gonadal organs that aren’t yet either ovaries or testicles. The chromosomes the embryo has determine how the gonads develop, and the hormones produced by the gonads determine a lot of other physical sex characteristics. If the embryo is XY, the gonads will develop into testicles. If it’s XX, the gonads will become ovaries. I’m simplifying a lot here, but this will give you the basic jist.*

Both DMRT1 and FoxL2 are transcription factors, proteins that control how genetic information gets copied and expressed. They both exist in gonad cells, but the presence or absence of a Y chromosome determines which factor gets to take charge, and which genetic information is put to use. With a Y chromosome, DMRT1 is activated, and it turns undifferentiated gonadal cells into sperm-nurturing Sertoli cells. Without a Y chromosome, FoxL2 takes over, and those same undifferentiated gonadal cells become granulosa cells, which play several important roles in the ovaries. These transcription factors aren’t the only things governing the expression of sex characteristics, but they are important.

Zarkower and Bardwell’s team compared normal male mice to mutant males that were born lacking a DMRT1 transcription factor. On the surface, the mutant males looked physically male. They had testicles and a penis. But the cells that made up their testicles weren’t normal. By 28 days after birth, most of the testicular cells were expressing FoxL2. The mice looked male on the outside, but inside their gonadal cells were more like those of a female.

Next, the team tried deleting the DMRT1 transcription factor in adult male mice that had been born normal. Over time, these mice also began to show cellular changes toward FoxL2 expression and cells that behaved more like female granulosa cells than male Sertoli cells. Previous research by other scientists demonstrated that the same basic thing is true for females and FoxL2, Dr. Zarkower told me. Just reversed.

Turns out, biological sex determination in mice is kind of an ongoing battle. It doesn’t end during fetal development. It doesn’t even end at birth.

What’s that mean for humans? This part isn’t really clear yet. Naturally-occuring DMRT1 deletions are rare, but they do happen. They can end in a range of effects. Some genetic males born without DMRT1 have small or underdeveloped testes. Others are born with indeterminate physical sex. About 30% of the time, Zarkower said, a natural DMRT1 deletion leads to an XY female—someone who looks physically female on the outside, but who has male genes and nonfunctional gonads instead of either testicles or ovaries. Usually, nobody notices the difference until the person doesn’t experience a normal female puberty.

Because of that, I wondered whether DMRT1 could be useful for women whose biological sex doesn’t match their female gender identity. If deleting DMRT1 can make an adult male body become more feminized, could doctors someday use that trick to intentionally help transition a biologically male body into a more female one?

Unfortunately, Zarkower doubts that would work. “This is very new and there’s a lot we don’t know yet, but the external genitalia didn’t change,” he said. “DMRT1 null mice were born physically male, they just didn’t go through puberty properly. In adults, this was basically the same as removing the testes. There would be hormonal changes, but it wouldn’t have an appreciable effect for external genitalia.”

Beyond that, he said, what happens in mice may or may not translate to humans. For instance, because of the way our genes work, all male mammals have two copies of DMRT1. Mice don’t seem to need both. If you delete one of the copies in a male mouse, the mouse will be essentially normal. Humans, on the other hand, have to have both copies for normal development. More problematic, in humans, mutations of DMRT1 are strongly linked to testicular cancer. “I’d be reluctant to mess around with this in humans,” Zarkower said.

For now, the main thing we can take away from this discovery is a gentle reminder that our bodies really are weird and wonderful. Even if you’re already used to thinking about gender as a fluid concept, it can be strange to realize how flexible biological sex is, as well. Don’t get too hung up on the idea that “male” and “female” must be set-in-stone categories. Nature certainly doesn’t treat sex that way.

King Tut—plus 10 other royal mummies—recently became the first ancient Egyptians to get their DNA analyzed. The results, published this week in the Journal of the American Medical Association, turned up a treasure trove of new information about the famous boy king, his family and Egyptian royalty in general. Among the discoveries:

• Tut had a bone disorder that would have forced him to walk with a cane, and which may have been a result of royal inbreeding.
• A mummy known as KV55 has turned out to be Tut's father, Akhenaten, a controversial pharaoh best known for his failed attempt at converting Egypt to monotheism. Based on sculptures and art that depict a feminized Akhenaten, researchers had long suspected that he suffered from a genetic hormone disorder called gynecomastia. But the DNA evidence says otherwise. Instead, Akhenaten's feminine features are likely to have been an artistic conceit, added for symbolic, religious reasons.
• Other previously unidentified mummies are now known to be Tut's grandfather, grandmother and mother.
• Contrary to speculation, Tut's mother probably wasn't his father's chief wife, Nefertiti. She and Akhenaten are never described as being related, and Tut is definitely the product of brother/sister incest.
• King Tut had malaria. He likely died from a combination of that disease and complications of his bone disorder. The malarial DNA found in Tut's body is the oldest genetic evidence of the disease ever found.

National Geographic News: King Tut was disabled, malarial and inbred