8 Astounding Facts About the Asteroid Belt

An artist's conception of the dwarf planet Ceres in the main asteroid belt.
An artist's conception of the dwarf planet Ceres in the main asteroid belt.
ESA/ATG medialab

The asteroid belt tells the story of the creation of the solar system. When it formed, not everything coalesced into a planet. Like LEGO bricks that never made it out of the bucket, these objects were organized by physics into a ring located between the orbits of Mars and Jupiter. This is the asteroid belt. Here are some things you might not know about it.

1. THERE ARE MORE THAN A HALF-MILLION ASTEROIDS.

The asteroid belt in black and white.
iStock

Over a half-million asteroids have been discovered by scientists, with hundreds of thousands yet to be found. They are generally divided into three classes: S-type (for stony); C-type (chondrites, largely composed of carbon, the most common—and perhaps the oldest—of the bunch); and M-type (metallic). The asteroids range in length from 30 feet to 330 miles. For the most part, they are oddly shaped, and, like the planets, spin (though not always so eloquently). Some asteroids have moons; some have two. Not every asteroid is located in the asteroid belt. Some, called Trojans, share the orbit of Jupiter. Some lurk perilously close to Earth. These are called near-Earth asteroids.

2. ASTEROID MEANS "STAR-LIKE."

A night sky with a shooting star.
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The first asteroid was discovered in 1801 by Giuseppe Piazzi, though he didn't know it at the time. He thought he had discovered the long-sought planet between Mars and Jupiter. He named his discovery Ceres, after the Roman goddess of harvest (and namesake to the word cereal, though that word wouldn't be coined until 1818).

Just over a year later, another "planet" was discovered. And another. And another. Eventually, there were so many planets that astronomers threw up their hands and gave the whole group a new classification: asteroid, or "star-like" in Greek. The name was chosen because they appeared, well, star-like in telescopes; they would not resolve as discs as planets do. Ceres's run as a planet lasted about 60 years before it was demoted to asteroid. In 2006, the International Astronomical Union reclassified it again, this time as a dwarf planet. This is the same decision that designated Pluto as a dwarf planet, though there is some debate on this point.

3. ALL THE ASTEROIDS IN IT DON'T ADD UP TO MUCH.

An artists' rendering of the asteroid belt.
iStock

It's likely that illustrations you've seen of the asteroid belt are not drawn to scale. If all of the objects in the asteroid belt were brought together and made into a single ball, its combined mass would only be 4 percent of the size of the Moon. In fact, Ceres alone accounts for one-third of the total mass of the asteroid belt. 

4. FLY YOUR SPACESHIP INTO IT. YOU WON'T HIT ANYTHING.

A little girl plays with a toy rocketship in a space system.
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What’s the biggest misconception that people have about the asteroid belt? Mental Floss asked Dante Lauretta, the principal investigator of the OSIRIS-REx mission to the asteroid Bennu (which once lived in the main asteroid belt before being jarred loose by Saturn and sent on a course for the inner solar system). His response: The Empire Strikes Back. People imagine "that it's this tumbling, highly energetic boulder field with things crashing into each other constantly, and Han Solo has to dodge and weave to avoid collisions," Lauretta says.

But the asteroid belt is downright spacious. If the arcade game Asteroids were real, it would pretty much consist of a ship and a black screen and … nothing to shoot. "When you fly a spacecraft through the asteroid belt, it’s a real challenge to actually get close enough to an asteroid to see it," Lauretta explains. "You have to specifically target it." There are, on average, 620,000–1.8 million miles between asteroids.

5. THE HISTORY OF THE SOLAR SYSTEM IS HIDDEN WITHIN.

An artist's concept of the solar system.
iStock

Back in the 1980s, scientists really set about spectrally classifying each object in the asteroid belt, and they discovered a compositional gradient. There were a lot of dark, carbonaceous objects in the outer asteroid belt, and brighter, "ordinary chondritic," S-type material in the inner asteroid belt. Spectral surveys today are starting to get really detailed, and scientists are getting a good look at objects as small as 6 miles across. As they get into asteroid compositions, they are discovering a fine structure in the compositional pattern, and placing it in the context of the dynamic state of the early solar system.

"Organics and ices are going to be stable farther out [in the belt], and metals and rocks are going to be stable farther in. You expect to see that," says Lauretta. "But now you're starting to see that there really are organic-rich and water-rich materials in the main belt. It's a small fraction of it, but it's a significant fraction. And there's rocky and bright material in the outer belt." That distribution of material is a record of migration of giant planets and the dynamical evolution of the solar system.

"I think we're going to be able to piece together a much more complex, chemical-dynamical coupled model of the evolution of the solar system, and see it almost like the stratigraphic layers of the geologic record. It will tell us the story of the evolution of the belt—not just the initial protoplanetary disk which established that chemistry, but how major events in the evolution of our solar system modified that distribution."

6. SCIENTISTS ARE SEARCHING FOR ITS MOST ANCIENT OBJECTS.

An asteroid in space.
iStock

Presently, planetary scientists are trying to identify and understand the primordial structures in the asteroid belt much in the same way that paleontologists or geologists search for the earliest signs of the origin of life in the geologic record. "That's where the biggest challenge lies," says Lauretta. "There is, in the most ancient examples, a discrete signal that you've got to pull out. It's going to be very tiny."

Scientists endeavor to understand what has been preserved from the dawn of the solar system—what they can trust as a true primordial signature of how our planetary system formed—versus what has been eroded or modified or changed over 4.5 billion years of evolution. "Trying to pick out that starting condition and targeting our scientific investigations into those areas is where the greatest challenge lies."

NASA's recently announced Lucy mission to multiple asteroids will help do this. "Everybody thinks those Trojans are the ones that hold that key to the earliest, most primitive material of the solar system," says Lauretta. "The Lucy team can get out there and do some cool science."

7. ASTEROIDS ARE LIKE SNOWFLAKES.

A snowflake in snow on a dark background.
iStock

No two are exactly alike, and each one has its own story to tell. "Every asteroid is a unique world to explore, and that is awesome," says Lauretta. "There is so much diversity and so many challenges out there. When we truly get out there and start poking around, we're going to see some stuff happening that we never even dreamed of."

8. NASA IS GOING BIG ON ASTEROIDS.

An artist's drawing of Dawn firing its engines above Ceres.
NASA/JPL-Caltech

NASA's Dawn spacecraft is currently in orbit around Ceres, where it continues to characterize that object and how it changes as it circles the Sun. (It previously orbited Vesta, making it the only spacecraft to orbit two extraterrestrial bodies.) NASA's OSIRIS-REx will arrive at the asteroid Bennu in August 2018. Earlier this year, the agency approved two missions to small bodies: the spacecraft Psyche will travel to the asteroid 16 Psyche, a mysterious, all-metal world. (It might once have been the core of a protoplanet.) The Lucy mission will travel to five Trojan asteroids that share Jupiter's orbit. The Japanese Space Agency's Hayabusa 2 spacecraft will arrive next year at Ryugu (a.k.a. 1999 JU3), a near-Earth asteroid. Like OSIRIS-REx, it will take a sample and return it to Earth for analysis.

And that analysis is serious business. In the case of samples and meteorites, Lauretta says, "most people don't realize that we pick apart these things grain by grain, atom by atom, isotope ratio by isotope ratio, and put together detailed stories about what happened billions of years ago in our solar system."

10 of the Most Popular Portable Bluetooth Speakers on Amazon

Altech/Bose/JBL/Amazon
Altech/Bose/JBL/Amazon

As convenient as smartphones and tablets are, they don’t necessarily offer the best sound quality. But a well-built portable speaker can fill that need. And whether you’re looking for a speaker to use in the shower or a device to take on a long camping trip, these bestselling models from Amazon have you covered.

1. OontZ Angle 3 Bluetooth Portable Speaker; $26-$30 (4.4 stars)

Oontz portable bluetooth speaker
Cambridge Soundworks/Amazon

Of the 57,000-plus reviews that users have left for this speaker on Amazon, 72 percent of them are five stars. So it should come as no surprise that this is currently the best-selling portable Bluetooth speaker on the site. It comes in eight different colors and can play for up to 14 hours straight after a full charge. Plus, it’s splash proof, making it a perfect speaker for the shower, beach, or pool.

Buy it: Amazon

2. JBL Charge 3 Waterproof Portable Bluetooth Speaker; $110 (4.6 stars)

JBL portable bluetooth speaker
JBL/Amazon

This nifty speaker can connect with up to three devices at one time, so you and your friends can take turns sharing your favorite music. Its built-in battery can play music for up to 20 hours, and it can even charge smartphones and tablets via USB.

Buy it: Amazon

3. Anker Soundcore Bluetooth Speaker; $25-$28 (4.6 stars)

Anker portable bluetooth speaker
Anker/Amazon

This speaker boasts 24-hour battery life and a strong Bluetooth connection within a 66-foot radius. It also comes with a built-in microphone so you can easily take calls over speakerphone.

Buy it: Amazon

4. Bose SoundLink Color Bluetooth Speaker; $129 (4.4 stars)

Bose portable bluetooth speaker
Bose/Amazon

Bose is well-known for building user-friendly products that offer excellent sound quality. This portable speaker lets you connect to the Bose app, which makes it easier to switch between devices and personalize your settings. It’s also water-resistant, making it durable enough to handle a day at the pool or beach.

Buy it: Amazon

5. DOSS Soundbox Touch Portable Wireless Bluetooth Speaker; $28-$33 (4.4 stars)

DOSS portable bluetooth speaker
DOSS/Amazon

This portable speaker features an elegant system of touch controls that lets you easily switch between three methods of playing audio—Bluetooth, Micro SD, or auxiliary input. It can play for up to 20 hours after a full charge.

Buy it: Amazon

6. Altec Lansing Mini Wireless Bluetooth Speaker; $15-$20 (4.3 stars)

Altec Lansing portable bluetooth speaker
Altec Lansing/Amazon

This lightweight speaker is built for the outdoors. With its certified IP67 rating—meaning that it’s fully waterproof, shockproof, and dust proof—it’s durable enough to withstand harsh environments. Plus, it comes with a carabiner that can attach to a backpack or belt loop.

Buy it: Amazon

7. Tribit XSound Go Bluetooth Speaker; $33-$38 (4.6 stars)

Tribit portable bluetooth speaker
Tribit/Amazon

Tribit’s portable Bluetooth speaker weighs less than a pound and is fully waterproof and resistant to scratches and drops. It also comes with a tear-resistant strap for easy transportation, and the rechargeable battery can handle up to 24 hours of continuous use after a full charge. In 2020, it was Wirecutter's pick as the best budget portable Bluetooth speaker on the market.

Buy it: Amazon

8. VicTsing SoundHot C6 Portable Bluetooth Speaker; $18 (4.3 stars)

VicTsing portable bluetooth speaker
VicTsing/Amazon

The SoundHot portable Bluetooth speaker is designed for convenience wherever you go. It comes with a detachable suction cup and a carabiner so you can keep it secure while you’re showering, kayaking, or hiking, to name just a few.

Buy it: Amazon

9. AOMAIS Sport II Portable Wireless Bluetooth Speaker; $30 (4.4 stars)

AOMAIS portable bluetooth speaker
AOMAIS/Amazon

This portable speaker is certified to handle deep waters and harsh weather, making it perfect for your next big adventure. It can play for up to 15 hours on a full charge and offers a stable Bluetooth connection within a 100-foot radius.

Buy it: Amazon

10. XLEADER SoundAngel Touch Bluetooth Speaker; $19-$23 (4.4 stars)

XLeader portable bluetooth speaker
XLEADER/Amazon

This stylish device is available in black, silver, gold, and rose gold. Plus, it’s equipped with Bluetooth 5.0, a more powerful technology that can pair with devices up to 800 feet away. The SoundAngel speaker itself isn’t water-resistant, but it comes with a waterproof case for protection in less-than-ideal conditions.

Buy it: Amazon

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

8 Facts About David Bowie's 'Space Oddity'

Express/Express/Getty Images
Express/Express/Getty Images

On July 20, 1969, astronauts walked on the Moon for the first time. Just a few weeks earlier, another space-age event had rocked the world: David Bowie’s single “Space Oddity” hit airwaves. The song, whose lyrics tell the story of an astronaut’s doomed journey into space, helped propel the artist to icon status, and five decades later, it’s still one of his most popular works. 

1. "Space Oddity" was inspired by 2001: A Space Odyssey.

Many listeners assumed that "Space Oddity" was riffing on the Apollo 11 Moon landing of 1969, but it was actually inspired by a Stanley Kubrick film released a year earlier. Bowie watched 2001: A Space Odyssey multiple times when it premiered in theaters in 1968. “It was the sense of isolation I related to,” Bowie told Classic Rock in 2012. “I found the whole thing amazing. I was out of my gourd, very stoned when I went to see it—several times—and it was really a revelation to me. It got the song flowing.”

2. "Space Oddity" was also inspired by heartbreak.

The track was also partly inspired by the more universal experience of heartbreak. Bowie wrote the song after ending his relationship with actress Hermione Farthingale. The break inspired several songs, including “Letter to Hermione” and “Life on Mars,” and in “Space Oddity,” Bowie’s post-breakup loneliness and melancholy is especially apparent.

3. "Space Oddity" helped him sign a record deal.

In 1969, a few years into David Bowie’s career, the musician recorded a demo tape with plans to use it to land a deal with Mercury Records. That tape featured an early iteration of “Space Oddity,” and based on the demo, Mercury signed him for a one-album deal. But the song failed to win over one producer. Tony Visconti, who produced Bowie’s self-titled 1969 album, thought the song was a cheap attempt to cash in on the Apollo 11 mission, and he tapped someone else to produce that particular single.

4. The BBC played "Space Oddity" during the Moon landing.

"Space Oddity" was released on July 11, 1969—just five days before NASA launched Apollo 11. The song doesn’t exactly sound like promotional material for the mission. It ends on a somber note, with Major Tom "floating in a tin can" through space. But the timing and general subject matter were too perfect for the BBC to resist. The network played the track over footage of the Moon landing. Bowie later remarked upon the situation, saying, "Obviously, some BBC official said, 'Oh, right then, that space song, Major Tom, blah blah blah, that’ll be great. 'Um, but he gets stranded in space, sir.' Nobody had the heart to tell the producer that."

5. David Bowie recorded an Italian version of "Space Oddity."

The same year "Space Oddity" was released, a different version David Bowie recorded with Italian lyrics was played by radio stations in Italy. Instead of directly translating the English words, the Italian songwriter Mogul was hired to write new lyrics practically from scratch. "Ragazzo Solo, Ragazza Sola" ("Lonely Boy, Lonely Girl") is a straightforward love song, and Major Tom is never mentioned.

6. Major Tom appeared in future songs.

Major Tom, the fictional astronaut at the center of "Space Oddity," is one of the most iconic characters invented for a pop song. It took a decade for him to resurface in David Bowie’s discography. In his 1980 single "Ashes to Ashes," the artists presents a different version of the character, singing: "We know Major Tom's a junkie/Strung out in heaven's high/Hitting an all-time low." Bowie also references Major Tom in "Hallo Spaceboy" from the 1995 album Outside.

7. "Space Oddity" is featured in Chris Hadfield's ISS music video.

When choosing a song for the first music filmed in space, Canadian astronaut Chris Hadfield naturally went with David Bowie’s out-of-this-world anthem. The video above was recorded on the International Space Station in 2013, with Hadfield playing guitar and singing from space and other performers providing musical accompaniment from Earth. Some lyrics were tweaked for the cover. Hadfield mentions the "Soyuz hatch" of the capsule that would eventually shuttle him to Earth.

8. "Space Oddity" played on the Tesla that Elon Musk sent to space.

Dummy in Tesla roadster in space with Earth in background.
SpaceX via Getty Images

In 2018, Elon Musk used SpaceX's Falcon Heavy rocket to launch his Tesla Roadster into space. The car was decked out with pop culture Easter eggs—according to Musk, "Space Oddity" was playing over the car’s radio system during the historic journey. The dummy’s name, Starman, is the name of another space-themed song on Bowie's 1972 masterpiece The Rise and Fall of Ziggy Stardust and the Spiders from Mars.