Moon: Facts about our planet's lunar companion

Our natural satellite is the moon. It is larger than the dwarf planet Pluto. The moon is one-fourth the size of the planet and has a lower density, which means it has less gravity.

We have recently learned about the moon.

How did the moon form?

The moon's formation is thought to have taken place 4.5 billion years ago, not long after the solar system was born. There were a lot of space rocks in our neighborhood. Astronomers theorize that the early Earth was hit by a body called Theia. Our atmosphere would have been destroyed and the moon would have been formed.

There is a possibility that our planet was turned into a synestia after Theia destroyed it. The material at the outer edges of the space doughnut coalesced into small moons. The theory says that Earth's pull allowed it to steal the moon from Venus.

The moon has been with us since the beginning of time and has been called many things. The English word Luna is derived from the Latin word Luna. Selene is the name of a mythical moon goddess and the study of the moon's geology is called Seleology.

The moon is the second-brightest object after the sun. Its light is reflected off its surface by the sun. The same side of the moon always faces us because it is so close to our planet.

There are fun facts about the moon.

Our planet's oceans are tugged by the moon's gravity to rise and fall in sequence. High tide occurs on the side of Earth closest to the moon, while simultaneously happening on the other side due to the inertia of water. There are low tides between these points.

The moon's surface

There are large dark features on the moon. According to NASA, the seas were once thought to be bodies of water. The areas were carved billions of years ago when lava flowed over the moon.

The moon's face is pockmarked by craters because of billions of years of being hit by space objects. The scars from the event that formed them can't be erased because the moon has no atmosphere or active plate tectonics. The South Pole-Aitken Basin is one of the oldest and deepest impact holes on the moon. Scientists don't know how it came to be.

According to Live Science's sister site Space.com, the lunar surface contains roughly 43% oxygen, 20% Silicon, 19% magnesium, 10% iron, 3% calcium, 3% aluminum, 0.42% chromium, 0.18% titanium and 0.12% manganese, by weight.

The dark regions at its poles are believed to hold trace amounts of water.

According to NASA, the moon's crust is 70 km deep and it's rocky mantle is 1,330 km thick. Most of the moon is made of rocks with iron and magnesium. It's relatively small core makes up just 1% to 2% of its mass.

The moon's atmosphere

The moon has an extremely thin atmosphere of gas. The Earth's atmosphere at sea level is around a billion billion times more potent than that of the planet. The total mass of the moon's gasses is over 50,000 lbs. According to Space.com, it's the same weight as a dump truck.

The moon's atmosphere contains a wide range of gasses, including oxygen, methane, nitrogen, carbon dioxide, carbon dioxide, sodium, potassium, and polonium. The moon cooled and some elements came from that. Comets delivered others.

Moon dust is made from volcanic glass that has been smashed out of the lunar soil. The thin lunar atmosphere means these fragments hardly ever erode and so dust on the moon is caustic, clogging the equipment and zippers Apollo astronauts brought to the moon, as well as being toxic for human health

Moon exploration

The moon is the main target of human exploration efforts since the beginning of the Space Age and remains the only body besides Earth that humans have set foot upon. The Apollo program brought astronauts to the moon on July 20, 1969 and won the space race for the United States.

Instruments placed on the moon during Apollo have given scientists a lot of information, for instance, that the moon is moving away from Earth by about 1.5 inches per year and that many moonquakes originate from cliff-like cracks on the lunar surface. The Apollo astronauts brought back a lot of weight. According to NASA, there are samples of moon rocks that are still being studied and yielding new insights.

The Russian and Chinese probes have both landed on the moon. Both India and Israel attempted to place landers on the moon. One of the few cases of space junk hitting our satellite was caused by a discarded Chinese rocket booster. NASA renewed its interest in the moon once again with its Artemis program, which hopes to place astronauts on its surface by 2024 and use our satellite as a launching point to Mars.

Recent discoveries about the moon

New things about the moon are found by lunar researchers.

• The moon is slightly younger than previously believed. Though earlier estimates thought the moon to be around 4.51 billion years old, simulations have suggested that its true age is closer to 4.425 billion years.
• The surface of the moon is rusting, turning a tiny bit red as the Earth’s atmosphere interacts with lunar iron.
• Though tiny amounts of water have been known to exist on the moon’s surface since 2009, it wasn’t until 2020 that scientists spotted it in shadowed regions on the moon’s sunlit side.
• Much like a comet, the moon has a long tail made of sodium atoms blasted out of the lunar soil by meteor strikes and then pushed hundreds of thousands of miles downstream by solar radiation. The Earth sometimes wears this tail like a scarf.
• China’s Yutu 2 rover has spotted all sorts of strange rock formations on the moon, including glass spheres thought to have been created either during meteor impacts or in ancient lunar volcanoes. Earlier, the robot photographed a square-shaped hut-like object that turned out to be a rock vaguely resembling a rabbit.
• Faint magnetic fields have long been detected on the moon, and nobody quite knows why they exist. But recent research has suggested that these magnetic anomalies may help trap water ice in certain places.
• Material collected during the Apollo era has yielded tons of amazing scientific findings. After cracking open a tube of moon rocks and dust that had been sealed for 50 years, scientists were able to grow plants in this lunar soil (opens in new tab) sample.

Additional resources

Live Science contributor Adam Mann updated the article.