The natural phenomenon described by the gravitational interaction between Earth and Moon is what?

• A. Eclipses
• B. Tides
• C. Moon Phases
• D. Currents

Answer: (B)

Tides are caused by the Moon’s gravity tugging on Earth's oceans. The side of Earth that faces the Moon is pulled a bit more strongly, creating a bulge toward the Moon, while the opposite side bulges due to inertia. As Earth rotates, coastlines move through these bulges, producing the regular rise and fall of sea levels we feel as high and low tides. The Sun also pulls on Earth’s oceans, but because it’s much farther away, its effect is smaller; the Moon’s gravity is the main driver.

When the Sun, Moon, and Earth align, their gravitational forces combine to create higher high tides and lower low tides—spring tides. When the Sun and Moon are at right angles relative to Earth, their effects partially cancel, leading to lower high tides and higher low tides—neap tides.

Other options don’t describe the gravitational effect between Earth and Moon. Eclipses involve shadows from alignments, not direct gravity. Moon phases describe how the Moon’s appearance changes due to its position relative to the Sun. Currents are large-scale ocean movements driven by winds and other forces, not specifically the Moon’s gravity.