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Look Up Tonight! The Super Beaver Moon Is Here

Have you heard about the supermoon tonight? Have you heard that it’s going to be big? Huge! Terrifying! The last time a full moon appeared this large, they say, the astronaut corps consisted of a single monkey named Albert, who would soon be shot into space on a V2 rocket. (Things did not end well for Albert, nor for his successor, Albert II.) It hasn’t seemed this big since 1948! What celestial chaos can we expect?

Take a deep breath. Technically, the supermoon’s peak will occur tomorrow morning, November 14, at 8:52 a.m. EST. But we think you should go out tonight (and maybe tomorrow night too). It’s going to be a pretty big full moon, and yes, it will likely be the biggest you’ve ever seen (and will not see again until November 25, 2034), but “biggest” is a relative term. If you didn’t already know that this supermoon would be juicing, you probably wouldn’t have really noticed. So what’s going on up there?

OUR MOON IS WEIRD

Relative to the Earth, the Moon is really big. Only gas giants Saturn and Jupiter possess larger moons, though it seems more through attrition than anything else. They’re working with overwhelmingly superior planetary sizes and moon totals, in comparison to our pale blue dot. Jupiter’s diameter is 11 times that of the Earth; Saturn’s diameter, 9.5 times. The two colossal planets have in their orbits a total of 129 known moons—and yet all but four of them are smaller than the lone Moon of our little world (our newly discovered mini-moon–like asteroid excluded).

If our moon is unique, its orbit is even wackier. Some might call it downright weird. The Moon's orbit is really far from Earth, and the tilt of its orbit is large to the point of being inexplicable. Scientists are pretty certain that a massive collision between the Earth and another planet sent debris into space that would eventually coalesce to form the Moon. Existing models for this, however, have never adequately been able to account for the moon’s large tilt.

One recent hypothesis for the Moon’s odd behavior states that the “Big Whack” changed our axial tilt by as much as 80 degrees and sent us spinning incredibly fast. That initial high tilt―the Earth might once have spun on its side―would explain how we managed eventually to slow back down. According to the same model, the Moon’s orbit of the Earth on the outset was 15 times closer than it is today, and that as it migrated away from the Earth, the Sun began to exert influence on its orbit. The whack, the tilt, the speed, the Sun―taken together, they offer a compelling explanation for the Moon’s odd orbital tilt today.

ENJOY TONIGHT’S MOON FOR ITS OWN SAKE

Because the Moon’s orbit is elliptical, when it is closest to the Earth in a revolution―a.k.a. at perigee―it appears larger; when it is at apogee, or farthest away, it appears smaller. Perigee and apogee are not identical from orbit to orbit. The Earth and the Moon both fall under the gravitational influence of the Sun.

When perigee coincides with a full moon, you get what is colloquially called a “supermoon.” (Not an astronomy term.) The full moon in November is called the Beaver Moon. (Also not an astronomy term.) Long ago, this was considered the time to set your beaver traps so that you would have enough pelts to make winterwear. Because tonight’s perigee brings the surfaces of the Earth and the moon a scant 216,486 miles apart, the supermoon will appear up to 14 percent bigger. But unless you’re a devoted Moon watcher, you might have a hard time spotting that. The moon will also be 30 percent brighter, NASA says, because of the Earth’s proximity in its orbit from the Sun. In all, it’s going to be a gorgeous super beaver moon, but it won’t change your life. Set your expectations accordingly.

So hope for clear skies, go outside―maybe even dust off the telescope, uncork a bottle of wine, and make an evening of it―and enjoy the Moon for the same reason you enjoy the constellations, meteor showers, the movement of the planets, and the appearance of the International Space Station. (If it's cloudy, check out the livestream from Slooh.) Because space isn’t somewhere out there. Earth is as much “in space” as any other object in the universe. We are part of space. And to peer into the night sky is to look simultaneously at the distant past of the universe, and the near future of humankind.

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Look Up! Residents of Maine and Michigan Might Catch a Glimpse of the Northern Lights Tonight
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iStock

The aurora borealis, a celestial show usually reserved for spectators near the arctic circle, could potentially appear over parts of the continental U.S. on the night of February 15. As Newsweek reports, a solar storm is on track to illuminate the skies above Maine and Michigan.

The Northern Lights (and the Southern Lights) are caused by electrons from the sun colliding with gases in the Earth’s atmosphere. The solar particles transfer some of their energy to oxygen and nitrogen molecules on contact, and as these excited molecules settle back to their normal states they release light particles. The results are glowing waves of blue, green, purple, and pink light creating a spectacle for viewers on Earth.

The more solar particles pelt the atmosphere, the more vivid these lights become. Following a moderate solar flare that burst from the sun on Monday, the NOAA Space Weather Prediction Center forecast a solar light show for tonight. While the Northern Lights are most visible from higher latitudes where the planet’s magnetic field is strongest, northern states are occasionally treated to a view. This is because the magnetic North Pole is closer to the U.S. than the geographic North Pole.

This Thursday night into Friday morning is expected to be one of those occasions. To catch a glimpse of the phenomena from your backyard, wait for the sun to go down and look toward the sky. People living in places with little cloud cover and light pollution will have the best chance of spotting it.

[h/t Newsweek]

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Kevin Gill, Flickr // CC BY-2.0
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10 Facts About the Dwarf Planet Haumea
Kevin Gill, Flickr // CC BY-2.0
Kevin Gill, Flickr // CC BY-2.0

In terms of sheer weirdness, few objects in the solar system can compete with the dwarf planet Haumea. It has a strange shape, unusual brightness, two moons, and a wild rotation. Its unique features, however, can tell astronomers a lot about the formation of the solar system and the chaotic early years that characterized it. Here are a few things you need to know about Haumea, the tiny world beyond Neptune.

1. THREE HAUMEAS COULD FIT SIDE BY SIDE IN EARTH.

Haumea is a trans-Neptunian object; its orbit, in other words, is beyond that of the farthest ice giant in the solar system. Its discovery was reported to the International Astronomical Union in 2005, and its status as a dwarf planet—the fifth, after Ceres, Eris, Makemake, and Pluto—was made official three years later. Dwarf planets have the mass of a planet and have achieved hydrostatic equilibrium (i.e., they're round), but have not "cleared their neighborhoods" (meaning their gravity is not dominant in their orbit). Haumea is notable for the large amount of water ice on its surface, and for its size: Only Pluto and Eris are larger in the trans-Neptunian region, and Pluto only slightly, with a 1475-mile diameter versus Haumea's 1442-mile diameter. That means three Haumeas could fit sit by side in Earth—and yet it only has 1/1400th of the mass of our planet.

2. HAUMEA'S DISCOVERY WAS CONTROVERSIAL.

There is some disagreement over who discovered Haumea. A team of astronomers at the Sierra Nevada Observatory in Spain first reported its discovery to the Minor Planet Center of the International Astronomical Union on July 27, 2005. A team led by Mike Brown from the Palomar Observatory in California had discovered the object earlier, but had not reported their results, waiting to develop the science and present it at a conference. They later discovered that their files had been accessed by the Spanish team the night before the announcement was made. The Spanish team says that, yes, they did run across those files, having found them in a Google search before making their report to the Minor Planet Center, but that it was happenstance—the result of due diligence to make sure the object had never been reported. In the end, the IAU gave credit for the discovery to the Spanish team—but used the name proposed by the Caltech team.

3. IT'S NAMED FOR A HAWAIIAN GODDESS.

In Hawaiian mythology, Haumea is the goddess of fertility and childbirth. The name was proposed by the astronomers at Caltech to honor the place where Haumea's moon was discovered: the Keck Observatory on Mauna Kea, Hawaii. Its moons—Hi'iaka and Namaka—are named for two of Haumea's children.

4. HAUMEA HAS RINGS—AND THAT'S STRANGE.

Haumea is the farthest known object in the solar system to possess a ring system. This discovery was recently published in the journal Nature. But why does it have rings? And how? "It is not entirely clear to us yet," says lead author Jose-Luis Ortiz, a researcher at the Institute of Astrophysics of Andalusia and leader of the Spanish team of astronomers who discovered Haumea.

5. HAUMEA'S SURFACE IS EXTREMELY BRIGHT.

In addition to being extremely fast, oddly shaped, and ringed, Haumea is very bright. This brightness is a result of the dwarf planet's composition. On the inside, it's rocky. On the outside, it is covered by a thin film of crystalline water ice [PDF]—the same kind of ice that's in your freezer. That gives Haumea a high albedo, or reflectiveness. It's about as bright as a snow-covered frozen lake on a sunny day.

6. HAUMEA HAS ONE OF THE SHORTEST DAYS IN THE ENTIRE SOLAR SYSTEM.

If you lived to be a year old on Haumea, you would be 284 years old back on Earth. And if you think a Haumean year is unusual, that's nothing next to the length of a Haumean day. It takes 3.9 hours for Haumea to make a full rotation, which means it has by far the fastest spin, and thus shortest day, of any object in the solar system larger than 62 miles.

7. HAUMEA'S HIGH SPEED SQUISHES IT INTO A SHAPE LIKE A RUGBY BALL.

haumea rotation gif
Stephanie Hoover, Wikipedia // Public Domain

As a result of this tornadic rotation, Haumea has an odd shape; its speed compresses it so much that rather than taking a spherical, soccer ball shape, it is flattened and elongated into looking something like a rugby ball.

8. HIGH-SPEED COLLISIONS MAY EXPLAIN HAUMEA'S TWO MOONS.

Ortiz says there are several mechanisms that can have led to rings around the dwarf planet: "One of our favorite scenarios has to do with collisions on Haumea, which can release material from the surface and send it to orbit." Part of the material that remains closer to Haumea can form a ring, and material further away can help form moons. "Because Haumea spins so quickly," Ortiz adds, "it is also possible that material is shed from the surface due to the centrifugal force, or maybe small collisions can trigger ejections of mass. This can also give rise to a ring and moons."

9. ONE MOON HAS WATER ICE—JUST LIKE HAUMEA.

Ortiz says that while the rings haven't transformed scientists' understanding of Haumea, they have clarified the orbit of its largest moon, Hi'iaka—it is equatorial, meaning it circles around Haumea's equator. Hi'iaka is notable for the crystalline water ice on its surface, similar to that on its parent body.

10. TRYING TO SEE HAUMEA FROM EARTH IS LIKE TRYING TO LOOK AT A COIN MORE THAN 100 MILES AWAY.

It's not easy to study Haumea. The dwarf planet, and other objects at that distance from the Sun, are indiscernible to all but the largest telescopes. One technique used by astronomers to study such objects is called "stellar occultation," in which the object is observed as it crosses in front of a star, causing the star to temporarily dim. (This is how exoplanets—those planets orbiting other stars—are also often located and studied.) This technique doesn't always work for objects beyond the orbit of Neptune, however; astronomers must know the objects' orbits and the position of the would-be eclipsed stars to astounding levels of accuracy, which is not always the case. Moreover, Ortiz says, their sizes are oftentimes very small, "comparable to the size of a small coin viewed at a distance of a couple hundred kilometers."

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