Moon FactsAugust 2, 2008 at 12:31 pm | Posted in Science, Space | Leave a comment
Some interesting facts about the moon, and our 2nd moon, from the recent newsletter iShift, from the Institute of Noetic Sciences:
1. According to the leading theory, the Moon was created when a rock the size of Mars slammed into Earth, shortly after the solar system began forming, about 4.5 billion years ago.
2. Because of the Earth’s gravitational effects, the Moon’s orbital period and rotational period have come to be the same, so that the Moon always shows us the same face. (Thus, what some of us call the “dark side of the Moon” is more accurately called the “far side of the Moon.”) Many of the moons around other planets behave similarly.
3. In 1971, Apollo 14 astronaut Stuart Roosa took a bunch of seeds with him and, while Alan Shepard and Edgar Mitchell were busy walking on the surface, Roosa guarded his seeds. Later, the seeds were germinated on Earth, planted at various sites around the country, and came to be called the “Moon trees.” Most of them are doing fine today.
4. The Moon’s heavily cratered surface is the result of intense pummeling by space rocks between 4.1 billion and 3.8 billion years ago. These “scars” have not eroded because the Moon has no significant volcanic activity or weather.
5. In 1999, scientists found the Moon isn’t our only moon. A 3-mile- (5-kilometer-) wide asteroid may be caught in Earth’s gravitational grip, thereby becoming a satellite of our planet. Cruithne, as it is called, takes 770 years to complete a horseshoe-shaped orbit around Earth, the scientists say, and it will remain in a suspended state around Earth for at least 5,000 years.
6. The Moon is not round (or spherical). Instead, it’s shaped like an egg. If you go outside and look up, one of the small ends is pointing right at you.
7. Apollo astronauts used seismometers during their visits to the Moon and discovered that the gray orb isn’t a totally dead place, geologically speaking. Small moonquakes, originating several miles (kilometers) below the surface, are thought to be caused by the gravitational pull of Earth. Sometimes tiny fractures appear at the surface, and gas escapes.
8. Our Moon is bigger than Pluto. And at roughly one-fourth the diameter of Earth, some scientists think the Moon is more like a planet. They refer to the Earth-Moon system as a “double planet.”
9. Tides on Earth are caused mostly by the Moon, because the Moon’s gravity pulls on Earth’s oceans. High tide aligns with the Moon as Earth spins underneath, as well as on the opposite side of the Earth because gravity pulls Earth toward the Moon more than it pulls the water.
10. All of that tidal tugging has another interesting effect: Some of Earth’s rotational energy is stolen by the Moon, causing our planet to slow down by about 1.5 milliseconds every century, while the Moon is propelled about 3.8 centimeters higher in its orbit. Researchers say that when it formed, the Moon was about 14,000 miles (22,530 kilometers) from Earth. It’s now more than 280,000 miles (450,000 kilometers) away.