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Raul Arboleda/AFP/Getty Images

Look Up! It's the Snow Moon Lunar Eclipse Comet Spectacular

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Raul Arboleda/AFP/Getty Images

Last year it was all supermoons, all the time. This year it’s going to be eclipses. There’s the big one on August 21—start planning your trip now!—and leading up to it are a couple of smaller events, starting with a penumbral lunar eclipse tonight, and an annular solar eclipse later this month. The eclipse tomorrow night, February 10, will occur during a "Snow Moon," and if you stay up a little bit longer, you might even be able to spot a comet. In other words, if you’re looking for cheap date ideas for the last Friday before Valentine’s Day, you’ve come to the right place.


Full moons have names. They survive largely through the pages of the Farmer’s Almanac, a 99-year-old annual best known for its weather predictions. You might recall the Hunter's Moon, or the Harvest Moon, and who could forget the Beaver Moon?

Tonight’s moon is called the Snow Moon, named by the American Indians for the obvious reason: February is the snowiest month. (This moon was also sometimes called the "Hunger Moon," for the same reason, and the "Shoulder to Shoulder Around the Fire Moon.") Generally speaking, you get only one full moon per month. In fact, the word "month" is derived from "moon," referring to a full cycle of its phases. Next month is the Worm Moon, because with the onset of spring, you have the wormiest month. And so on.

If you decide to have a moonlit picnic with your sweetheart, that kind of trivia is solid gold.


So what of this eclipse business? You might notice also that the moon seems a little … off. I don’t want to get your hopes up here: You will not see a Pacman-like chomp taken out of the moon, nor any well-defined line that you can point at and say, "See that? That is the edge of the Earth’s shadow."

Penumbral eclipses are a bit subtler than that. What you’ll want to look for is a darker hue to pass across the lunar surface. That’s it, but it’s still really cool. What’s happening is this. Shadows have two elements: the umbra and the penumbra. The umbra is the darkest part of a shadow. (The red super harvest moon in 2015 was caused by the Moon passing into the umbra of the Earth’s shadow.) The penumbra is the much gentler, much blurrier shadow that surrounds the umbra. It’s the place where the light source (in this case the Sun) is partially blocked, but not entirely. That’s the part of the Earth’s shadow that the Moon will be passing through tonight. As long as you keep your expectations in check, you should enjoy the show.

(There’s also the antumbra, in which the object being shadowed is fully contained in the light source—we’ll talk more about that on February 26, when the Moon as seen from the Southern hemisphere will become a giant, terrifying ring of fire.)

If you live in North America, you can watch the penumbral eclipse on February 10 at precisely 7:43 p.m. EST.


There will also be a comet out for your pre-Valentines Friday date night viewing pleasure. Its full name is Comet 45P/Honda-Mrkos-Pajdušáková, but its friends call it "45P." It will be visible around 3:00 a.m. EST. This particular comet visits us every five years, and tonight is its closest approach to Earth in its orbit. You’ll be gazing in the vicinity of the constellation Hercules, and looking specifically for a teal dot with a tail.

Realistically speaking, though, will you be able to see it? If the light pollution in your area is nil, and if your eyes are well adjusted, there’s a very slim chance you’ll be able to spot it with your naked eyes. I would not risk a disappointing end to a date night, however. After checking out the eclipse, head inside where it’s warm and go to Slooh. At 10:30 p.m. EST, astronomers will begin coverage of the comet, and use telescopes to give you a much better view than you’ll find in the backyard. If you have a fireplace, all the better for setting the mood. It is a Shoulder to Shoulder Around the Fire Moon, after all.

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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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