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?


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.


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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NASA/Getty Images
Here's Where You Can Watch a Livestream of Cassini's Final Moments
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NASA/Getty Images

It's been a road trip like no other. After seven years and 2.2 billion miles, the NASA orbiter Cassini finally arrived at the Saturn system on June 30, 2004. Ever since, it's been capturing and transmitting valuable data about the distant environment. From sending the Huygens probe to land on the moon Titan to witnessing hurricanes on both of the planet's poles, Cassini has informed more than 3000 scientific papers.

It's been as impressive a mission as any spacecraft has ever undertaken. And tomorrow, Cassini will perform one last feat: sacrificing itself to Saturn's intense atmosphere. Project scientists are deliberately plunging it into the planet in order to secure just a little more data—and to keep the spacecraft, which is running low on fuel, from one day colliding with a Saturnian moon that might harbor life.

Because it won't have time to store anything on its hard drive, Cassini will livestream its blaze of glory via NASA. The information will be composed mostly of measurements, since pictures would take too long to send. Instead, we'll get data about Saturn's magnetic field and the composition of its dust and gas.

"As we fly through the atmosphere, we are able to literally scoop up some molecules, and from those we can figure out the ground truth in Saturn’s atmosphere," Scott Edgington, a Cassini project scientist, told New Scientist. "Just like almost everything else in this mission, I expect to be completely surprised."

The action will kick off at 7 a.m. EDT on Friday, September 15. Scientists expect to say goodbye to Cassini less than an hour later. 

While you wait for Cassini's grand finale, you can check out some essential facts we've rounded up from Saturn experts. And keep your eyes peeled for a full recap of Cassini’s historic journey: Mental Floss will be in the control room at the Jet Propulsion Laboratory in Pasadena, California, to offer a firsthand account of the craft's final moments in space. 

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Big Questions
What Are the Northern Lights?
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Over the centuries, many have gazed up at one of the Earth’s most fascinatingly beautiful natural wonders: the Northern Lights. In the past couple of weeks, some lucky American stargazers have gotten the chance to see them from their very own backyards—and could again this week, according to Thrillist. But what are they?

Before science was able to get a read on what exactly was happening in the night sky, ancient tribes had their own theories for what caused the jaw-dropping light show. Many early beliefs had roots in religion, such as that the light was a pathway souls traveled to reach heaven (Eskimo tribes) or that the light was an eternal battle of dead warriors (Middle-Age Europe). Early researchers were a bit more reasonable in their approximations, and most surrounded the idea of the reflection of sunlight off the ice caps. In 1619, Galileo Galilei named the lights the aurora borealis after Aurora, the Roman goddess of morning, after concluding they were a product of sunlight reflecting from the atmosphere.

Today, scientists have come to the general agreement that the lights are caused by the collision of electrically charged solar particles and atoms from our atmosphere. The energy from the collisions is released as light, and the reason it happens around the poles is because that's where the Earth’s magnetic field is the strongest. In 2008, a team at UCLA concluded that “when two magnetic field lines come close together due to the storage of energy from the sun, a critical limit is reached and the magnetic field lines reconnect, causing magnetic energy to be transformed into kinetic energy and heat. Energy is released, and the plasma is accelerated, producing accelerated electrons.”

"Our data show clearly and for the first time that magnetic reconnection is the trigger," said Vassilis Angelopoulos, a UCLA professor of Earth and Space Sciences. "Reconnection results in a slingshot acceleration of waves and plasma along magnetic field lines, lighting up the aurora underneath even before the near-Earth space has had a chance to respond. We are providing the evidence that this is happening."

The best time to see the Northern Lights is during the winter, due to the Earth’s position in relation to the sun (shorter days means darker night skies). And by the way, it’s not just the North Pole that puts on a show—there are Southern Lights, too. There are also aurora borealis on other planets—including Mars—so rest assured that future generations born “abroad” will not miss out on this spectacular feat of nature.

Haven’t seen them yet? Traditionally, the best places to catch a glimpse of the Northern Lights are in Iceland, Sweden, Norway, Finland, Greenland, northern Canada, and Alaska. Maybe you'll get lucky this week and sneak a peek from your very own window. Check out Aurorasaurus for regular updates on where they are showing.

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