Look Up! The Eta Aquarid Meteor Shower Is Here

Rocky Raybell via Flickr // CC BY 2.0
Rocky Raybell via Flickr // CC BY 2.0

Set your alarm for the predawn hours of Saturday May 6, go outside, and catch the Eta Aquarid meteor shower—one of two annual showers caused by the collision of the Earth and the debris field of Halley’s comet. It’s not the most spectacular shower of the year, but as it peaks tomorrow morning, you can count on it to deliver a ghostly streak of light every few minutes.

The shower is named for its seeming point of origin—the constellation Aquarius—but don’t confine your view to that one spot in the sky. The streaks of light will seem to be everywhere. If your eyes have adjusted to the darkness, the skies are clear, and the area is sufficiently dark, there’s an excellent chance you’ll see something special—no telescope or binoculars required.

HALLEY’S PHANTASM

Going back millennia, every 75 to 76 years the comet Halley has appeared in the sky, dazzling and mystifying the creatures of Earth. As of 1986—its last appearance over Earth—it was visible with the naked eye despite light pollution caused by poorly designed streetlights, ill-conceived fixtures, and the over and upward illumination of buildings in areas rural and urban alike. Most of us have never seen the night sky, but rather, some poor, washed out approximation of it. You look up, think you see space, and wonder why we’re spending so much money to visit so little. A proper night sky is a kaleidoscope of greens, blues, teals, and violets. There are more stars out there than grains of sand on the Earth. The first time you see the Milky Way in all its splendor, you may wonder why we do anything other than explore the cosmos.

milky way galaxy

Lukas Schlagenhauf via Flickr // CC BY-ND 2.0

All of this bears note because for most of Halley’s history, there were no electric lights to outshine the universe. There were no planes or space stations to make illuminated objects coursing across the sky humdrum affairs filtered from thought. When something moved in the night sky back then, it was stark, obvious, and unnerving. Today we see a meteor shower and wonder how long the faint show might last. Centuries ago, people saw meteor showers and wondered if the world were about to end. The first recorded showing of Halley was possibly in 476 BCE. Aeschylus hadn’t yet written Agamemnon. The Roman Republic was in its infancy. Its recurrence has been associated with the birth of Jesus (its appearance may have coincided with the Star of Bethlehem), has been seen as a harbinger of death for royalty, and was a guiding light for Genghis Khan. Astronomy has always been as much about humanity as it is about the cosmos.

HOW TO MAKE A METEOR

The same dark skies unobscured by light pollution would have made the Aquarids—and every meteor shower to some extent—must-see viewing. Its first recorded observance was in 401 CE (the Roman Empire still stood then), and it was officially discovered in 1870. Six years later, it was calculated that the parent of the meteor shower was none other than the famed comet Halley, and people really started taking notice. As a comet travels along its orbit, it leaves a fine debris field in its wake. The Earth, happy and oblivious along its orbit, eventually crosses into the field of dust and sand-sized particles that were once part of Halley, and the result is a meteor shower: specks of dust slamming into the Earth’s atmosphere at tens of thousands of miles per hour. As they are vaporized, energy is released, producing those famed streaks of light in the night sky. (Later in Earth’s orbit, it will encounter Halley’s debris field again: the Orionids in October.)

So how can you see the phantom trail of Halley’s comet? The most exciting way is to wake a couple of hours before dawn, lay out a blanket in some dark area, and look up. Once your eyes adjust, you should be able to catch about 10 meteors per hour. If that’s too much work for you—it’s hot out there, and mosquitoes, you know?—Slooh will be broadcasting the meteor shower live, with running commentary by astronomers.

Science Finds a Better Way to Calculate 'Dog Years'

thegoodphoto/iStock via Getty Images
thegoodphoto/iStock via Getty Images

Anyone who has ever owned a pet is likely familiar with the concept of “dog years,” which suggests that one year for a dog is like seven years for a human. Using this conversion metric, a 2-year-old dog is akin to a high school freshman, while a 10-year-old dog is ready for an assisted living facility.

If that seems rather arbitrary, that’s because it is. But now, researchers at the University of California, San Diego have come to a more data-based measurement on dog aging through DNA.

The paper, published on the preprint server bioRxiv, based the finding on DNA methylation, a process in which molecules called methyl groups attach themselves to DNA and serve as an indicator of aging. Generally speaking, the older living beings get, the faster the rate of methylation. In the study, 104 Labrador retrievers were examined, with subjects ranging from 1 month to 16 years old. The results of their DNA methylation were compared to human profiles. While the rate of methylation tracked closely between the two—young and old dogs had similar rates to young and old people—adolescent and mature dogs experienced more accelerated aging.

Their recommended formula for comparing dog and human aging? Multiply the natural logarithm of a dog’s age by 16, then add 31. Or, just use this calculator. Users will see that a 2-year-old dog, for example, wouldn’t be the canine equivalent of a 14-year-old. It would be equivalent to 42 human years old and should probably start putting money into a 401(k). But because methylation slows considerably in mid-life, a 5-year-old dog is approximately a 57-year-old human, while a 6-year-old dog is nearing 60 in human years—a minor difference. Things level out as the dog gets much older, with a 10-year-old dog nearing a 70-year-old human.

Different breeds age at different rates, so the formula might not necessarily apply to other dog breeds—only Labs were studied. The work is awaiting peer review, but it does offer a promising glimpse into how our furry companions grow older.

[h/t Live Science]

Sssspectacular: Tree Snakes in Australia Can Actually Jump

sirichai_raksue/iStock via Getty Images
sirichai_raksue/iStock via Getty Images

Ophidiophobia, or fear of snakes, is common among humans. We avoid snakes in the wild, have nightmares about snakes at night, and recoil at snakes on television. We might even be born with the aversion. When researchers showed babies photos of snakes and spiders, their tiny pupils dilated, indicating an arousal response to these ancestral threats.

If you really want to scare a baby, show them footage of an Australian tree snake. Thanks to researchers at Virginia Tech, we now know these non-venomous snakes of the genus Dendrelaphis can become airborne, propelling themselves around treetops like sentient Silly String.

That’s Dendrelaphis pictus, which was caught zipping through the air in 2010. After looking at footage previously filmed by her advisor Jake Socha, Virginia Tech Ph.D. candidate Michelle Graham headed for Australia and built a kind of American Ninja Warrior course for snakes out of PVC piping and tree branches. Graham observed that the snakes tend to spot their landing target, then spring upward. The momentum gets them across gaps that would otherwise not be practical to cross.

Graham next plans to investigate why snakes feel compelled to jump. They might feel a need to escape, or continue moving, or do it because they can. Two scientific papers due in 2020 could provide answers.

Dendrelaphis isn’t the only kind of snake with propulsive capabilities. The Chrysopelea genus includes five species found in Southeast Asia and China, among other places, that can glide through the air.

[h/t National Geographic]

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