The Earth’s most well-known co-orbital satellite, or object that shares the Earth’s orbit, is the Moon, but scientists believe the Earth has two additional co-orbital satellites: asteroids known as 3753 Cruithne and 2002 AA29. The asteroid known as 3753 Cruithne, sometimes referred to as Earth’s second moon, is more than 3 miles (5 km) across and orbits in sync with the Earth. The Earth’s other co-orbital satellite, 2002 AA29, is much smaller at just 196 feet (60 m) across, and it orbits the Earth in a horseshoe shape. Scientists estimate this smaller co-orbital satellite gets close to Earth every 95 years.
More about Earth:
- The Earth is actually not a perfect sphere. The distance between the North and South poles is about 26 miles (43 km) less than the Earth's diameter at the Equator.
- About 70% of the Earth is covered by oceans. The other parts are solid ground above sea level.
- Scientists believe there could have been a second moon in the past, as evidenced by terrain on the side of the moon that they theorize could be from a another moon crashing into it.