Little Helene. Image: NASA/JPL/Space Science Institute

Here’s one of the small moons of Saturn we don’t get to see too much of, named Helene.   Helene is pretty small as moons go, only 20 miles across.   Cassini did a pass at just a bit more than 1,300 miles and that is about as close as the spacecraft has come to the little moon.  The moon is a little off center,  it’s not easy getting these shots sometimes.  The moon appears very bright because it is bathed in reflected light from Saturn.  There are other images, but they need to be processed by the Cassini team before they can be used, you can see them in the raw images section of the Cassini site (linked below), and you will understand what I am talking about.  I included an image from 2007 which you can see by clicking the image above AND there is going to be another flyby in April so hopefully the angles will be better. Still a good picture though.

Anyways, Helene is notable because it is what is known as a Trojan moon, meaning it is gravitationally tied to a larger moon, in this case, Dione, and Helene stays 60 degrees (400,000km/250,000 miles) ahead of the larger moon.

One of the big questions is:  how did this moon come to be gravitationally tied to Dione, maybe it blown off another in an impact.  Another is: is the moon’s leading edge coated with material from the “E” ring.

Have a look at the press release here.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

The giant montane pitcher plant is a botanical predator, ruthlessly luring in prey and feasting on its victims–except when it’s not. Researchers have discovered that the carnivorous plant is mighty adaptable; when there’s no prey around, it thrives just fine on the poop of a tree shrew that lives in Borneo’s mountains.

The pitcher plant is the world’s largest meat-eating plant; in low altitudes it feeds on ants, small insects, and possibly even small rodents. The plant entices its prey with tasty nectar, and when the animals lose balance and drop into the fluid-filled pitcher, they’re drowned and ingested.

But in Borneo’s higher altitudes, there aren’t enough gullible and clumsy insects to keep the plant alive. So, evolutionary forces pressured the plant to tweak its design a bit to entice the tree shrew to pay it a visit and poop into it.

The BBC describes the unique toilet-shaped plant:

N. rapah pitchers have huge orifices, but they also grow large concave lids held at an angle of about 90 degrees away from the orifice. The inside of these lids are covered with glands that exude huge amounts of nectar. Most importantly, the distance from the front of the pitcher’s mouth to the glands corresponds exactly to the head to body length of mountain tree shrews.

The shrew perches on the plant to lick nectar from the “lid” and on most occasions it poops into the conveniently positioned toilet bowl to mark its territory. Scientists have yet to determine if the nectar has some sort of laxative qualities to it.

The feces collect at the bottom of the plant and when it rains, the nutrients get flushed into the plant, where the nitrogen and phosphorous in the poo get absorbed as plant food. This toilet bowl system is so effective that the plant satisfies almost all its nutritional needs from the shrew feces.

Jonathan Moran, one of the scientists who studied the relationship between the plant and the shrew, suggests that both parties evolved to sustain each other through a process called “mutualism.” For the shrew, the pitcher plant’s nectar is a rich source of sugar in the mountains; for the plant, the shrew’s feces is food.

You can listen to Moran explain the unique relationship in a radio program, CBC’s “Quirks and Quarks” here. And here’s a video of the tree shrew plopping into the pitcher plant for a quick snack.

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Image: Chi’en Lee

The BBC is reporting that a previously unknown potential impact crater has surfaced in the Congo. This region was heavily forested, hiding the crater, but recent widespread deforestation has revealed the ancient impact scar.

Obviously, I’m conflicted about this.

If this is an impact crater (it has not yet been confirmed), it’s about 40 km (25 miles) across, making it one of the largest seen on the Earth. We haven’t been hit by a big asteroid in a long time, and erosion has erased most of the impact craters. There’s a picture of the crater on that link above, and the crater is obviously very old.

It’s fascinating to know that such a large feature can be hidden at all, but it’s sad indeed on how it got uncovered. I can hope no one would be so crass as to suggest we should continue to deforest our planet in hopes of finding more treasures, but I have seen far worse things suggested to support unrestrained mining, drilling, and polluting. I’m glad something good came of this horrific practice, but all things told, I think I’d rather it had remained tucked away among thousands of square kilometers of trees.

Tip o’ the Whipple Shield to Ted Judah.

The theory of general relativity: It works. OK, it’s not exactly Earth-shattering news that Albert Einstein’s century-old idea works in real life. That’s been shown over and over. But what had been difficult for researchers to do until now was verify the theory on truly massive scales beyond the solar system, that of whole galaxies and clusters of galaxies. This week in Nature, Reinabelle Reyes and colleagues report that they did it, and that Einstein was proven correct once more.

While the find is a nice coup for Reyes’ team, its importance goes beyond just reaffirming the great scientists of yesteryear with yet another “Einstein was right” story. The existence of dark matter and dark energy is based on the assumption that Einstein’s gravity is affecting galaxies billions of light-years from Earth in the same way that it affects objects in our solar system [National Geographic]. However, if the study had shown that general relativity needed a slight adjustment at vast distances (like the nudge Einstein himself provided to Newton’s physics), that could have altered prevailing ideas about dark matter and energy. This research indicates those pesky ideas may be here to stay [Space.com].

Reyes’ approach combined the study of galaxies’ gravitational lensing (how much they bend the light from surrounding galaxies), their velocities, and how and where they formed clusters. All of these measurements combined created a system to test theories of gravity independent of particular parameters in the theories [Space.com]. What they found closely matched what you’d predict under general relativity. They tested two alternative gravitational theories, too. One, called tensor-vector-scalar (TeVeS), gave results beyond the study’s margin of error. Another, called f(R), didn’t work as well as general relativity. But it fell within the margin of error, so the scientists say it will take more research to disprove it.

Meanwhile, as the spirit of general relativity is reaffirmed in the pages of Nature, the pages upon which Einstein formulated the theory are going on display in Jerusalem. Elsa, his wife, gave the pages to Hebrew University, and they are currently part of 50th anniversary festivities at the Israel Academy of Sciences and Humanities. Each of the 46 pages, labored over between November 1915 and their publication in May 1916, has its own case, each lighted dimly in a room that has been darkened to protect the paper. There on Page 1 is the now familiar title in German: “The Foundation of the General Theory of Relativity” [The New York Times].

However, if you need more Einstein and can’t make the trip to Israel, check out his mustachioed mug on the cover of the April DISCOVER issue, on newsstands this week.

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Image: Ferdinand Schmutzer