11 Spectacular Facts About the Moon

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

The Moon is Earth’s closest satellite in our solar system, but in many ways, we hardly know our neighbor. Scientists aren’t entirely sure how it formed, and other facts, like its shape (more egg-like than spherical), and the consistency of its surface (dusty but firm), were confirmed only recently. With the 50th anniversary of the Apollo 11 Moon landing this year, and NASA preparing to return to the lunar surface for the first time in decades, it’s time to brush up on these facts about the Moon—from colorful names for full moons to the first landing on the dark side of the Moon.

1. The Moon may have formed when a giant object in the solar system hit Earth.

Scientists aren't in total agreement on how the Moon formed, but the most widely accepted theory is the giant impact hypothesis. According to this theory, an object the size of Mars called Theia collided with Earth 4.5 billion years ago when the solar system was still new and chaotic. The impact dislodged matter from Earth’s crust, and the debris attached to whatever was left of Theia through the force of gravity.

This scenario would explain why the Moon is made up of lighter elements found in Earth’s outer layer, but it still leaves some questions unanswered. If the giant impact hypothesis is correct, about 60 percent of the Moon should consist of the impact object. Instead, its composition is almost identical to that of Earth. There are alternative explanations: one posits that the Moon is a space object that got caught in Earth’s orbit, and another one suggests the Moon and Earth formed at the same time, but none is as popular as the giant impact theory.

2. The Moon is the perfect size for solar eclipses.

Moon covering sun during solar eclipse.
Masashi Hara/Getty Images

A lucky set of circumstances make total solar eclipses, as seen from Earth, possible. The Moon is just the right size and distance from our planet to appear as the same size as the Sun in the sky. When the Moon passes between the Sun and the Earth, it covers the Sun perfectly with an impressive corona illuminating its edges. If it were any smaller or farther from Earth, it would look like a blot on the Sun during a solar eclipse.

3. A full Moon has different nicknames in different seasons.

A full moon can have many colorful names, but they don’t always describe a special celestial phenomenon. Some are used to refer to a full moon that appears during a certain time of year. A harvest moon, which is the full moon closest to the autumn equinox, is the best-known example, but there are many others, including a wolf moon (first full moon of January), strawberry moon (June), and sturgeon moon (August).

4. It’s the largest moon in the solar system relative to its planet.

Our Moon isn’t the largest in the solar system (that distinction goes to Ganymede, one of Jupiter’s 79 moons), but it is the biggest in relation to the planet it orbits. With a diameter of 2159 miles and a surface area of 14.6 million square miles, the Moon is a little more than one-fourth the size of Earth. The dwarf planet Pluto has an even smaller moon-to-planet ratio. Pluto’s largest moon Charon is nearly the size of its host body, leading some astronomers to refer to the pair as a double-dwarf planet.

5. The Moon is shaped like a lemon.

The Moon may look perfectly round in the night sky, but it’s actually more of an oval shape. It came out wonky billions of years ago when super-hot tidal forces shaped its crust, heating up some areas hotter than others to form a lemon shape rather than a perfect sphere. Gravitational forces from Earth have helped to exaggerate the Moon’s oblong appearance over eons.

6. Scientists thought Moon dust would cause lunar landers to sink.

Lunar module over moon's surface.
NASA/Newsmakers

When preparing to send missions to the Moon, some scientists feared that a thick layer of dust on the body’s surface would cause complications. One of the strongest proponents of the dust theory was Thomas Gold, an astrophysicist at Cornell University. He insisted that the Moon was covered in seas of dust soft and thick enough to swallow a lunar lander. Though the Moon’s surface is dusty, the layer is too thin to cause problems, as the successful landings of the Soviet Luna 9 and the American Surveyor spacecrafts proved in 1966.

7. The Moon is international property.

Astronauts Buzz Aldrin and Neil Armstrong may have planted an American flag on the Moon in 1969, but it belongs to the world. Countries like the Soviet Union and the U.S. made sure of that at the height of the space race in 1967 when they signed the Outer Space Treaty, a document declaring that the Moon would be a “global commons” and any resources discovered there would be used for the good of the world overall. In keeping with the spirit of the agreement, NASA shared soil samples taken from the Moon with Soviet scientists upon the Apollo 11 mission's return.

8. Humans have left strange things on the Moon.

Since the first people landed on the Moon in 1969, its surface has been home to more than just dust. Earth artifacts left on the Moon by astronauts include two golf balls, an obscene Andy Warhol doodle, and a message from Queen Elizabeth II. Eugene Cernan, Apollo 17 commander and one of the last people to walk on the Moon, traced his daughter’s initials into the soil when he visited in 1972. Without any wind or weather on the Moon, the letters TDC could remain there forever.

9. The "dark side of the Moon" is the result of synchronous rotation.

Even though the Moon is constantly rotating, only one side of it is visible from Earth. This is because the Moon is locked in synchronous rotation. It takes the Moon just as long to complete one full rotation as it does for the body to orbit around the Earth once, so the same side always faces our planet. This isn’t a coincidence—the Earth’s gravitational forces have gradually pulled the tip of the slightly oblong Moon to point toward the planet, creating something called tidal lock.

In January 2019, the Chinese space agency landed the first lunar probe on the unexplored dark side of the Moon. The Chang'e 4 spacecraft sent the first photographs of a massive impact crater on the dark side to Earth, giving scientists their first glimpse of that unknown region.

10. One astronaut was allergic to the Moon.

Apollo 17 astronaut Harrison “Jack” Schmitt discovered the hard way that some people are allergic to Moon matter. Following a survey of a valley in the Sea of Serenity, he climbed back into the crew’s lunar module and tracked in a lot of Moon dust with him. The dust affected him as soon as he removed his spacesuit, triggering red eyes, sneezing fits, and other symptoms that lasted two hours.

11. Humans are going back to the Moon soon.

After completing several manned missions to the Moon, NASA ended the Apollo program in 1972 as budgets tightened and public interest waned. That means most people alive today have never witnessed a manned lunar landing, but now, following a hiatus nearing 50 years, NASA is finally preparing to return to the Moon. The next manned lunar expedition will be ready to launch “no later than the late 2020s,” according to the space agency. One of the goals will be placing a command module, called Gateway, in the Moon’s orbit that astronauts can reuse over multiple missions.

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.

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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]

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