9 Essential Facts About Saturn

This portrait looking down on Saturn and its rings was created from images obtained by NASA's Cassini spacecraft on October 10, 2013.
This portrait looking down on Saturn and its rings was created from images obtained by NASA's Cassini spacecraft on October 10, 2013.
NASA/JPL-Caltech/Space Science Institute/G. Ugarkovic

Saturn is the planet you always drew in elementary school because without those rings, it's just a circle. But what is Saturn, anyway, and what makes it special to planetary scientists? Now is a good time to find out: On September 15, the scientists who operate the Cassini spacecraft—which they've used to study the gas giant for 13 years—are going to intentionally destroy Cassini by sending it on a crash course with Saturn. The data it will send back before it meets its fiery demise will be priceless.

Mental Floss is going to be inside mission control at NASA's Jet Propulsion Laboratory in Pasadena, California, as the scientists send Cassini on its grand finale mission. We'll have a full dispatch for you. In anticipation, we spoke to Saturn experts to find out what you need to know about the planet before Cassini takes its final plunge.

1. SATURN BY THE NUMBERS.

At 75,000 miles across, Saturn is nearly 10 times larger than Earth and the second-largest planet in the solar system, behind its neighbor, Jupiter. It is called a gas giant, meaning it is really big and made mostly of gas: in this case, hydrogen and helium. The deeper you get into Saturn, the greater the pressure and heat. How bad could it be, you ask? Bad enough that hydrogen exists as a liquid metal near the planet's core. In other words, don't expect astronauts to plant flags down there anytime soon. One Saturn year lasts about 30 Earth years, and one Saturn day is, well …

2. THE LENGTH OF A SATURNIAN DAY IS A MYSTERY.

The spacecraft Cassini has been operating in the Saturnian system for 13 years doing extraordinary science—and yet the length of a day on Saturn remains elusive. Is it 10 hours and 39 minutes, as suggested by data from Voyager 2 in 1981? Or is it 10 hours and 47 minutes, as Cassini data suggested when the spacecraft first arrived at Saturn in 2004? Or is it 10 hours 33 minutes, as later data suggested?

The problem is that Saturn keeps giving new answers. There are no continents spinning around for scientists to set a stopwatch to; cloud orbits are unreliable; and measurements of the planet's radio radiation and magnetic fields have proven equally frustrating. As Cassini completes its final orbits, it is collecting up-close Saturn data that might finally answer the question. No matter the number to be determined, 10 hours and change is a tremendous speed for a planet of Saturn's size to be spinning, and it affects even the planet's shape; its poles are flattened as a result of its rotation.

3. SATURN HAS SEASONS.

Visiting space aliens would never confuse Saturn with Earth, though the two planets do have one interesting shared characteristic: both are tilted to similar degrees relative to the equator of the Sun. Earth is tilted at 23.5 degrees; Saturn is tilted at 26.7 degrees. Axial tilt is the reason we experience seasons, and Saturn is no different (though the leaves there don't change color due to a pronounced lack of trees). Saturn experienced summer solstice four months ago, marking its maximum axial tilt toward the Sun and making it midsummer in Saturn's northern hemisphere. It will reach Autumn equinox in May 2025.

4. HERE'S MORE ABOUT CASSINI, NASA'S MOST AMBITIOUS PLANETARY MISSION EVER.

After 20 years in space—seven years en route to Saturn and 13 years in orbit around it—the Cassini spacecraft is nearly out of fuel for its thrusters. Rather than enter a permanent orbit around Saturn as an artificial satellite, or sent on an intercept course with Uranus, both risky endeavors, Cassini will burn up like a shooting star when it plunges into the depths of Saturn on September 15. For the past six months, Cassini has been taking daring dives through Saturn's rings in a series of 22 orbits, the last of which will send it on an impact course with the planet. As it speeds into the gas giant, it will return data on the composition of Saturn's atmosphere. Cassini's death mission will protect the moons Enceladus and Titan from contamination by Earth germs. 

5. ENJOY TERRIBLE WEATHER? YOU'D LOVE LIFE ON SATURN.

"Saturn has these absolutely massive storms once every few decades," says Sarah Hörst, a planetary scientist at Johns Hopkins University, "and we actually got to see one of them happen because we've been there so long." Scientists already knew about the storms from Earth-based observation, but close-up study made possible by Cassini gave new insights on how they work and what they do. "These massive storms actually pull up a lot of material from deeper in the atmosphere—stuff that we can't usually see or measure," she tells Mental Floss. This material consists of gases from deep within the planet's atmosphere. Saturn's storms cause dramatic temperature changes, and even have lightning. "If you were somehow managing to stand inside of Saturn's atmosphere, some of the storms would feel quite familiar, and some of these longer-lived storms, these vortexes, are somewhat related to a hurricane."

6. IT HAS A CORE, BUT DETAILS ABOUT IT ARE HAZY.

Saturn has a rocky core surrounded by liquid metallic hydrogen, though the finer details of the planet's interior remain elusive. At Jupiter, NASA's Juno mission is hard at work determining the nature of that planet's core. The 22 proximal orbits of Cassini's "grand finale" have a configuration similar to those of Juno, and scientists hope that data from these orbits can be used with Juno data to learn more about Saturn's interior. "The general picture that there's rocky stuff down there, probably metallic hydrogen, isn't really going to change," says Hörst. "The details of exactly how it looks and where its phase changes are—those types of things—will hopefully be worked out a bit more before Cassini ends."

7. YOU CAN SEE SATURN FROM YOUR BACKYARD.

When the skies are conducive to viewing, even a modest telescope can allow you to see Saturn. It will look just like you imagine: a ball surrounded by a distinctive ring structure. It will even "feel" three dimensional (because it is, of course) in a way that Jupiter or Mars will not. Your telescope might even allow you to spot Titan, Saturn's largest moon. Sky & Telescope offers a guide to help you see Saturn in all its glory.

8. ITS MOONS MIGHT BE YOUNGER THAN SOME DINOSAUR FOSSILS.

Earth's moon is about 4.5 billion years old. Saturn's moons are mere infants in comparison: possibly as young as 100 million years old. Matija Cuk, a research scientist at SETI, modeled the orbital evolution of the Saturn system, and found that the orbital shifts of the moons over time, and the gravitational influences of the moons over each other, suggest origins when dinosaurs ruled the Earth. "If calculations predict that something happened in the past and you don't see it, maybe it never happened," he tells Mental Floss. One scenario sees a different inner moon system whose orbits resonated and eventually crossed, causing the moons to collide. The current system of moons then assembled from the debris.

Those rings around Saturn might not be very old, either, and might be related to the young moons. "The rings might be pieces of broken up moons," he says. "You figure out how old the rings are and you can figure out the last time the moons were broken up and when some of them were put back together."

9. THERE'S A GOOD CHANCE THAT LIFE EXISTS ON THOSE MOONS.

Enceladus, one of Saturn's moons, possesses a global saltwater ocean surrounded by an icy crust. That ocean is in direct contact with a rocky core. Saltwater touching rock is exciting because it allows for interesting chemistry—including the sort that might be conducive to life. Adding to the excitement are hydrothermal vents on the sea floor, spewing water, minerals, and nutrients heated by geothermal activity. Better yet, that ocean is being blasted into space through massive geysers. This means NASA can get to the water, sample it, and hopefully, find life.

Titan, another moon of Saturn, also possesses the right stuff for life—and not boring old liquid water life, either, but something wholly alien: a methane-based life form. Key to such life would be the presence of the molecule acrylonitrile, now known to exist on Titan. The European Space Agency landed the Huygens probe on Titan in 2005, and Cassini later discovered several massive liquid methane lakes on that world. The next step is to send a submarine there and get to work.

LEGO Is Launching an Official International Space Station Set

LEGO
LEGO

Not everyone can live out their childhood dreams of floating around in space aboard the International Space Station, but now you can at least construct a toy version of it for your own house.

Next month, LEGO is releasing an impressive model of the International Space Station as part of its Ideas program, which produces designs that were suggested by fans. This one was submitted three years ago by Christoph Ruge.

LEGO ISS
LEGO

According to TechCrunch, the kit includes the ISS, a dockable space shuttle, two astronaut figurines, and a satellite that you can “deploy” with the robotic Canadarm2 (which is used to capture and repair satellites on the ISS). It also comes with a display stand, so you can make it the eye-catching centerpiece of your coffee table if it happens to match your living room decor.

The ISS might not look as formidable as the life-size model of astronaut Buzz Aldrin that LEGO builders created last year, but that doesn’t mean it’s not difficult to construct—the 864-piece set is labeled for kids ages 16 and older.

LEGO ISS
LEGO

Having said that, it doesn’t mean that younger kids can’t help out with the assembly, or at least play with it once it’s complete. At about 7 inches high, 12 inches long, and 19 inches wide, the station could inspire the next generation of space explorers.

The $70 kit will be available on February 1 in LEGO stores or the LEGO website.

[h/t TechCrunch]

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A Snow Moon Will Light Up February Skies

makasana, iStock via Getty Images
makasana, iStock via Getty Images

February is the snowiest month of the year in many parts of the U.S., but on February 9, consider braving the weather outside to look up at the sky. That Sunday morning, the only full snow moon of the year will be visible. Here's what you need to know about the celestial event.

What is a snow moon?

If you keep track of the phases of the moon, you may already know that the full moon of each month has its own special name. Following January's wolf moon lunar eclipse is a snow moon in February. The name snow moon is said to have originated with Native American tribes, and it refers to the heavy snowfall that hits many parts of North America in February.

According to The Old Farmer's Almanac, different tribes had different names for February's full moon. The Wishram people named it the shoulder to shoulder around the fire moon and the Cherokee people called it the bone moon because animal bones were sometimes their only source of nutrition in the dead of winter. Snow moon is the name that's most commonly used by almanacs today.

When to See the Snow Moon

The moon will enter its next full phase the morning of Sunday, February 9. The snow moon will be at its fullest at 2:34 a.m. EST, but if you're not willing to stay up that late, it's still worth looking up. The previous evening—Saturday, February 8—the moon will be 99 percent illuminated on the East Coast. Check your local weather forecast and find a spot with clear skies to get the best view of the wintertime spectacle.

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