Likewise, scientists use time-variable gravity to study ground water fluctuations , sea ice, sea level rise, deep ocean currents, ocean bottom pressure, and ocean heat flux.
Land Snow and Ice Remote Sensing. EO Explorer. At the time of publication, it represented the best available science. As the Moon orbits the Earth, it drags along behind it a "bulge" in the oceans. On the side of Earth opposite the Moon, the gravitational pull is less than on any other part of the Earth and the oceans are "left behind" in another bulge. The Moon's contribution to Earth's tides is significant because it is so close. The Sun, of course, also exerts a powerful gravitational pull on Earth — that's what keeps Earth in a steady orbit.
Early in Earth's history, the Moon was even closer to Earth. Billions of years ago, the Moon was 10 times closer and tides were times higher. Scientists believe that these extreme tides occurred once every three hours because the Earth was spinning more rapidly.
The tides eroded the coastal areas, adding minerals to the oceans. These minerals may have been essential for life to evolve as quickly as it did.
Shining Light — Just like the planets, our Moon does not produce its own light. It "shines" because it reflects the Sun's light.
While careful statistical studies have shown no correlation between the full Moon and strange behavior, the full Moon's light does make it easier for humans and other animals to see — and be seen. Studies have documented changes in the success rates of predators and foraging patterns of prey animals due to this added nighttime illumination.
Corals time their mating events by the light of the Moon. Most other animal behaviors relating to the Moon are because the tides change the coastal environment. The Size of It — Despite the exaggerated size of the Moon in movies, books, and art, the Moon's apparent size is relatively small in the sky. The moon's gravitational pull on Earth is the strongest when the moon is at the perigee, which results in greater tide variation than normal. This variation creates slightly higher high tides and slightly lower low tides.
Conversely, the moon's "apogee" is the point in the lunar orbit when it is farthest from the Earth, which results in slightly lower tide variation than normal. The moon's proximity to the Earth causes it to exert a stronger gravitational pull than the sun does on the Earth. However, the sun's effect is magnified at certain times of the year, when Earth's elliptical orbit brings it closer to the sun. During this time, the alignment of the Earth, moon and sun creates spring tides that result in greater tidal variation.
The most significant spring tides occur three or four times per year, when the Earth is closer to the sun and the moon is at its perigee, resulting in perigean spring tides.
However, even under these conditions, high tides typically don't change enough to cause worrisome effects. This massive gravitational pull caused the surface of the moon to bulge toward Earth, similar to how the moon causes large bodies of water on Earth to bulge.
When an object is tossed off a building top or a cliff apex, for instance, it accelerates toward the ground at 9. The Moon's surface gravity is weaker because it is far less massive than Earth. A body's surface gravity is proportional to its mass, but inversely proportional to the square of its radius. The Apollo astronauts were able to walk on the lunar surface because the Moon exerted a gravitational pull on them.
Of course, the astronauts were able to leap higher on the Moon than on Earth because the Moon's surface gravity is so comparatively weak. When on Earth, a fully suited Apollo astronaut weighed about pounds, equipment included.
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