Tides

• Tide


  The regular rise and fall in the level of water in the ocean
• Tides


  • They are the chief and the most observable effect of the moon's gravitational pull on Earth
• Spring tides


  Higher than usual high tides and lower than usual low tides, occurring during full moon and new moon when the Sun, Moon, and Earth are in line
• Neap tides


  Lower than usual high tides and higher than usual low tides, occurring when the Sun, Moon, and Earth are at right angles
• When the moon is at perigee


  The tide-raising force is greater than normal by about 20%
• The planets and their satellites are opaque bodies in space that block the path of light coming from the sun, casting shadows
• When the moon passes between the Earth and the sun, it casts an umbra (full shadow) and penumbra (partial shadow) on the Earth, causing a solar eclipse
• When the Earth passes between the sun and the moon, it casts an umbra on the moon, causing a lunar eclipse