Last year, we celebrated 50 years since humans first walked on the moon. That was a long time ago. Yet, we’re still exploring space today. We’ve sent lots of spacecraft to look at the rest of our solar system. These missions are unmanned.
One of the latest missions went back to the moon, but to a different part of it. The moon goes around Earth once a month, and the same side always faces Earth. All the men who have visited the moon landed on the near side, the side we can see from Earth. So have all the unmanned spacecraft that safely landed on the moon.
In 2019, however, China landed a spacecraft on the far side of the moon. It landed in a huge crater. Billions of years ago, a large object hit this area, carving out the crater. The impact was so big, it kicked up rocks from the moon’s mantle. That’s the layer of rock that lies below the crust. The spacecraft will study these rocks and see what the moon’s mantle is made of.
A view of Earth from the surface of the moon
Luna 9
Apollo 11
near side
Chang'e-4
far side
All landings—manned or unmanned—have taken place on the near side of the moon. An unmanned Chinese spacecraft recently landed on the far side.
former USSR
United States
manned Apollo missions
China
Measuring 'Marsquakes'
The moon is large, but it’s not a planet. Planets are large, round, and orbit, or go around, the sun. Our moon doesn’t orbit the sun. Instead, it orbits Earth. Earth is a planet, because it goes around the sun. There are other planets. One of the nearest to Earth is Mars. People may travel there someday.
In 2018, the United States’ National Aeronautics and Space Administration (NASA) landed a spacecraft on Mars called InSight. It’s studying things that are happening inside the planet. In 2019, InSight detected the first “earthquakes” ever observed on Mars. Good thing InSight’s monitors are sensitive because these marsquakes were very weak. If you stood on the surface, you wouldn’t even feel them.
This artist’s rendering shows the InSight spacecraft investigating Mars’ interior.
Assessing Asteroids
Beyond the path of Mars are lots of small, rocky objects that go around the sun. These are asteroids. Asteroids are small and irregular. They are important to study because long ago objects similar to them came together to build rocky planets like Earth and Mars. Asteroids may also have valuable minerals that we could mine.
Some asteroids come close to Earth. A Japanese spacecraft is exploring one such asteroid named Ryugu. Pictures from the spacecraft indicate Ryugu is not perfectly round. Instead, it’s shaped like a cube, and it has lots of boulders. Last year, the spacecraft shot a bullet at the asteroid. The blast kicked up material, some of which the spacecraft caught. The spacecraft will bring that material home so scientists can study it.
Another spacecraft launched from the United States (U.S.). It’s exploring an asteroid named Bennu. Bennu is even smaller than Ryugu: less than a third of a mile across. The spacecraft will sample the asteroid and later bring that sample back to Earth.
This image shows the Bennu asteroid next to the Eiffel Tower, for scale.
