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 Built a Life-Sized Astronaut Model to Celebrate the 50th Anniversary of Apollo 11

The LEGO Group
The LEGO Group

The LEGO Group is honoring the 50th anniversary of the Apollo 11 mission in a way that only LEGO can: with a life-sized astronaut model constructed entirely from LEGO blocks.

The 6-foot-3-inch model matches the space suit worn on the Moon by astronaut Edwin “Buzz” Aldrin on July 21, 1969, down to the American flag patch on his left shoulder. The front of the helmet even mimics the well-known photo of Aldrin standing on the Moon’s surface, with his helmet reflecting his own shadow and fellow Moon-walker Neil Armstrong in the near distance.

The feat took a team of 10 designers and LEGO Master Builders 300 hours and 30,000 LEGO bricks to complete, and you can see it in person on Washington, D.C.’s National Mall as part of the Smithsonian’s National Air and Space Museum’s Apollo 50 Festival from July 18 to July 20.

Though the astronaut model is already complete, there’s still tons to build—during the festival, you can help Master Builders assemble mosaic backdrops of the Moon and Mars, and you can even lend a hand in the construction of a 20-foot-tall replica of NASA's Space Launch System rocket, the vehicle NASA is developing to potentially use to send humans to Mars in the future.

The LEGO Group is also displaying an 11-foot-tall replica of a rocket at the Ontario Science Centre in Canada from now through September 2. It contains not only an impressive 80,000 bricks, but also built-in lights, sound, and a fog machine to simulate a rocket launch.

Buzz Aldrin on the Moon
Buzz Aldrin walks on the Moon.
NASA, Wikimedia Commons // Public Domain

It’s all part of a LEGO initiative to inspire a new generation of children to be enthusiastic about—and personally involved in—the future of space exploration. In addition to its brick-based efforts, the company is currently partnering with Scholastic on a program to send 50 kids to NASA Space Camp next year. “We will continue to inspire children to dream about what’s possible and to grow up to pursue STEM careers, said Bettina Inclán, associate administrator for communications at NASA’s Washington, D.C. headquarters.

Check out LEGO’s space-related collections—featuring Mars exploration, women of NASA, a recreation of the Moon landing, and more—on its online store.

Mental Floss has affiliate relationships with certain retailers and may receive a small percentage of any sale. But we choose all products independently and only get commission on items you buy and don't return, so we're only happy if you're happy. Thanks for helping us pay the bills!

A Half-Blood Thunder Moon Will Light Up Tonight’s Sky

Matt Cardy, Stringer/Getty Images
Matt Cardy, Stringer/Getty Images

Today, July 16, 2019, marks 50 years since NASA launched the Apollo 11 lunar mission. In case you needed another reason to look up at the sky on this date, tonight's Moon will be a special one. It's the only full moon of July, and in some parts of the world, it will appear partially eclipsed, making for a rare half-blood thunder moon, according to Space.com.

The meaning of the name thunder moon has nothing to do with lightening and storm clouds. The full moon of each month of the calendar year is given a special nickname from folklore. January's is a wolf moon, March's is a worm moon, and June's is a strawberry moon. The full moon that appears in July is commonly called a thunder moon, because thunderstorms are frequent this time of year, but it can also be referred to as buck moon because July is when deer antlers are at their fullest.

There's another factor that makes tonight's Moon worth watching. Starting at 2:43 p.m. EDT, the Moon will enter a partial lunar eclipse. That means part of the full moon will pass through the shadow of the Earth, making one section of it appear darker than the rest. A full lunar eclipse is known as a blood moon due to the reddish hue it takes on in our planet's shadow. Tonight's event isn't a full eclipse, so it's being called a half-blood moon even though it may not take on a coppery tone. The partial lunar eclipse will reach its peak at 5:30 p.m. EDT, and conclude at 8:17 p.m. Unfortunately that means the eclipse won't be visible from the U.S., but spectators in Europe, Africa, South America, and parts of Asia will get to see the full show.

July is shaping up to be an exciting month for stargazers. On July 9, Saturn reached opposition, making it look especially large and bright in the night sky. The planet is no longer at peak visibility, but it will be easy to spot with the naked eye from now through September. If you're already planning at looking up at the Moon tonight, here's how to find Saturn at the same time.

[h/t Space.com]

SECTIONS

arrow
LIVE SMARTER