Rhea (R-4) Flyby

It seems a long way to go for a simple answer, but the Cassini R-4 Rhea Flyby slated for Saturday morning (shortly after ten, Pacific Time) is just one of the many simple answers sought by scientists studying the Saturnian system. And that simplicity, in a way, is a striking reminder of what humanity can achieve.

This gravity flyby is designed to understand the internal structure of Saturn’s second largest moon. Is Rhea a homogeneous body or did it differentiate into a core, mantle, and crust like the Earth? The radio science subsystem will use radio waves beamed to Earth to perform precise measurements designed to answer this question.

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Turtle Frogs

Ladies and gentlemen: turtle frogs.

Yep, you heard me right. Turtle frogs. Nature’s middle finger to those of us who thought we understood evolution well enough to get by. Arenophrynde rotunda, the Northern Sandhill Frog and Myobatrachus gouldii, the Western Australian frog. I’m told there exists a Southern Sandhill Frog, a.k.a. A. xiphorhyncha, but so little is known about it that I would feel silly pointing you to a reference.

Okay, that’s not entirely true, but neither is it a matter of simply being lazy.

Meanwhile, if you want to read up on M. gouldii, the Western Australian Museum has an excellent paper from Marion Antsis, Dale Roberts, and Ronald Altig on neobatrachial reproduction.

Meanwhile, see also:

Western Australia Museum: Frogwatch

Real Monstrosities, “Turtle Frog”

Wikipedia: Sandhill frog

Wikipedia: Myobatrachus goldii

Wikipedia: Neobatrachia

NEOSSat: Canada Looks to Protect the Planet

And you thought the Canadian Space Agency was only good for sending up Twitter-friendly astronauts? Well, ha! In the wake of this week’s NEO fever, with asteroids racing by, and rocks raining down from the sky, NEOSSat, the Near-Earth Object Surveillance Satellite currently under construction:

Slated for launch in 2013, it will circle the globe every 100 minutes, scanning space near the Sun to pinpoint asteroids that may someday pass near our planet. NEOSSat will also sweep the skies in search of satellites and space debris as part of Canada’s commitment to keeping orbital space safe for everyone. NEOSSat applies key technology already demonstrated in Canada’s very successful MOST satellite.

The suitcase-sized NEOSSat will orbit approximately 800 kilometres high above the Earth, searching for near-Earth asteroids that are difficult to spot using ground-based telescopes. Because of its lofty location, it is not limited by the day-night cycle, and can operate 24/7. The hundreds of images that NEOSSat will generate per day will be downloaded and analyzed by the University of Calgary’s NEOSSat science operations centre.

Ears In the Age of 3-D

Imagine, if you would, please, saying the following to your five year-old twin daughters: “I want to implant your ears on the backs of rats.”

Okay, that’s not nearly so creepy as it sounds. Nancy Shute of NPR explains:

To make the ear, Bonassar and his colleagues scanned the ears of his twin daughters, who were 5 at the time. They used a 3-D printer to build a plastic mold based on the scan. Those printers, similar to a home inkjet, lately have also been adapted to experiment with making chocolate, guns, and even kidneys.

They then injected a soup of collagen, living cartilage cells, and culture medium. The soup congeals “like Jell-O,” Bonassar tells Shots. “All this happens quickly. You inject the mold, and in 15 minutes you have an ear ready to go.”

Well, not exactly. What they have is an ear-shaped chunk of cells that would have to be tucked under the skin on the side of the head by a plastic surgeon before it could become an ear.

To test whether their ear-mold would become living, useful ear cartilage, the researchers implanted samples under the skin on the back of laboratory rats. In three months, cartilage cells took over the collagen, making for a solid-yet-flexible chunk of cartilage that retained its precise shape and size. The results were published online in the journal PLoS One.

The technique could be a breakthrough for microtia and anotia, related birth defects in which the pinna (the part of the ear on the outside of one’s head) is underdeveloped or absent, or even the occasional missing ear resulting from an accident. Microtia occurs in the range of once every eight- to ten-thousand births, and, in truth, I have no idea what the numbers are for accidental or necessary surgical removal of pinnae.

Still, though, as with so many breakthroughs we hear about, application is most likely ten years away at a minimum.

Decorah Rocks

Decorah, Iowa is a quiet sort of midwestern town. With a population of just over 8,100, the seven square miles of Decorah make up the Winneshiek County seat, right about where Route 52 crosses Highway 9. Once upon a time, the Winnebago tribe lived here after being driven from Wisconsin; the town is named after Waukon Decorah, who led Ho-Chunk Winnebago warriors alongside American forces in the Black Hawk War of 1832, and lived to see his people once again uprooted so that white American settlers could have the land. The good people of Decorah named their town after him, and then dug up what they believed was his body in 1859 in order to build over the gravesite. In 1876, they dug up the bones again, in order to renovate the courthouse.

The town is also home to Luther College and the Vesterheim Norwegian-American Museum. Each year, the town is flooded by thousands of tourists celebrating Norwegian heritage during Nordic Fest.

It is a picturesque little place in the American heartland.

And it also sits on a 470 million year-old cosmic impact crater:

An asteroid as big as a city block smashed into what is now northern Iowa about 470 million years ago, says a Smithsonian geologist, supporting a theory that a giant space rock broke up and bombarded Earth just as early life began flourishing in the oceans.

The impact dug a crater nearly four miles wide that now lies beneath the town of Decorah, said Bevan French, one of the world’s foremost crater hunters and an adjunct scientist at the National Museum of Natural History.

The asteroid that carved it would have dwarfed the estimated 55-foot-wide space rock that exploded over southern Russia on Friday.

The Decorah object smashed into bedrock with such force that it shattered tiny grains of minerals. French found this “shock quartz” in gravel from beneath the town, he told two dozen colleagues during a seminar at the museum last week.

Finding impact craters is rare, as erosion and the shifting of tectonic plates tend to erase them. The Decorah crater, if accepted by other scientists, would be just the 184th known, according to an international database at the University of New Brunswick.

But spying the evidence of the Earth’s most dramatic explosions requires only humble equipment — a simple black microscope. As sun streamed into French’s office above Constitution Avenue one recent afternoon, he placed a glass slide under the microscope’s lens and invited a reporter to peer in. A thin slice of rock from beneath Decorah sat on the slide.

Three white circles — quartz crystals no bigger than mustard seeds — popped into view. Dozens of parallel lines striped each circle: evidence of a rock-crushing pulse.

“They’re shattered,” French said of the crystals. Geologists consider shock quartz near-definitive evidence of an extraterrestrial impact.

The Decorah crater lay undiscovered until now because almost none of it peeks above ground. Instead, it is filled by an unusual shale that formed after an ancient seaway sluiced into the crater, depositing sediment and an array of bizarre sea creatures that hardened into fossils, French said.

This shale was the first clue that certain Iowans may be unknowingly living in a crater.

Copernicus

Here’s one to file under First World Problems: I use the search bar in my browser window, so I rarely see the Google home page.

Not much of a problem, is it? First world, or otherwise.

But today turns out to be the 540th birthday of Nicolaus Copernicus the Polish mathematician and astronomer who revolutionized the European view of the Universe by correctly theorizing a heliocentric solar system.

And, of course, Google marked the day with one of their festive logos.

Eoin O’Carroll explains, for The Christian Science Monitor, a bit about Copernicus’ celebrated discovery:

It’s astonishing to think that anatomically modern humans walked on this planet for nearly two hundred millennia before they realized that it was moving.

Then again, you can’t really blame us. Even though the equator is spinning at more than a thousand miles per hour, even though our planet is hurtling around our sun at about 66,000 miles per hour, even though our solar system and everything in it is careening around our galaxy at nearly half a million miles per hour, and even though our galaxy is whirling around at a mind-blowing 1.2 million miles an hour, the very fact that you’re not currently clinging to the ground for dear life makes it only natural to think of the Earth as 16th century astronomer Tycho Brahe did, as a “hulking, lazy body, unfit for motion.”

Nicolaus Copernicus’s book, titled “On the Revolutions of the Heavenly Spheres,” was published the year the Polish astronomer died, in 1543. It marked the beginning of an eclipse of a worldview dominated by the ideas of Aristotle, who believed that the Earth remained at rest while the sun, moon, other planets, and all the stars, which were made of an unchanging substance called aether, revolved around it in perfect circles.

Of course nothing is ever that simple. Our prehistoric ancestors observed five celestial bodies moving independently from the rest of the lights in the sky. These bodies would move slowly across the sky, loop backward for a few months, and then loop forward again. The ancient Greeks called them astēr planētēs, or “wandering stars,” and thought them to be living beings.

The looping behavior of these wanderers – whom today we know as the planets Mercury, Venus, Mars, Jupiter, and Saturn – presented a problem for ancient astronomers, many of whom would have loved nothing more than to have observed them circling above in a simple, orderly fashion, just as Aristotle said they did. But the heavens demanded a more nuanced explanation.

Happy birthday, Nicolaus.

e, Not E, and Before e-

Apparently, I missed e Day. More than likely, so did you. Don’t worry, though, there will be another chance this year, though you’ll be celebrating with Europeans.

Rhett Allain didn’t miss e Day:

Why is Feb. 7 e Day? Well, in the USA we use the Middle-endian date format. So, Feb. 7 would be commonly written as 2/7/13. Guess what? The first two digits of e are 2.7. If you live in other places you might use the little-endian date format. In this case 2/7/13 would be July 2. For those people, just consider this an early post.

But don’t get distracted. (Yes, my first question was the same as yours: “Really? It’s really called ‘Middle-endian’?”

But e Day is a celebration of e, the jealous little brother of π.

Allain offers his favorite definition: “e is the number that if you raise that number to the power x, the slope of the function is the same value as the function.”

And it just goes downhill from there. Or uphill, I guess, if you look at it on a graph. Sort of. The graph at right does not show you e. Maybe you could try reading the Wikipedia entry on e, but that’s the fun thing about being a poor mathematician and clueless excuse for a scientist.

Sometimes called Euler’s number after the Swiss mathematician Leonhard Euler, e is not to be confused with γ—the Euler–Mascheroni constant, sometimes called simply Euler’s constant. The number e is also known as Napier’s constant, but Euler’s choice of this symbol is said to have been retained in his honor.

By the time you get to the part about derangements, well, yeah.

Oh, right. e = 2.71828 (and a whole bunch of numbers after that; it’s irrational and trancendental, just like π).

That’s No Moon, It’s … Oh, Wait, It’s a Moon

So the Death Star joke has been done to death, and Cassini’s 2010 photo of Mimas has become pretty much the standard picture for the second smallest of the planemo (planetary-mass object) moons around Saturn, which has enough moons that astronomers haven’t finished naming them all^†.

JPL explains the famous Death Star picture:

Herschel Crater is 130 kilometers, or 80 miles, wide and covers most of the right of this image. Scientists continue to study this impact basin and its surrounding terrain (see PIA12569 and PIA12571).

Cassini came within about 9,500 kilometers (5,900 miles) of Mimas on Feb. 13, 2010.This mosaic was created from six images taken that day in visible light with Cassini’s narrow-angle camera on Feb. 13, 2010. The images were re-projected into an orthographic map projection. This view looks toward the area between the region that leads on Mimas’ orbit around Saturn and the region of the moon facing away from Saturn. Mimas is 396 kilometers (246 miles) across. This view is centered on terrain at 11 degrees south latitude, 158 degrees west longitude. North is up. This view was obtained at a distance of approximately 50,000 kilometers (31,000 miles) from Mimas and at a sun-Mimas-spacecraft, or phase, angle of 17 degrees. Image scale is 240 meters (790 feet) per pixel.