lunar parallax
Quick Summary
In astronomy, parallax is the apparent shift in the position of a celestial object when viewed from two different locations. This shift is used to measure distances to objects in space.
Lunar parallax specifically refers to the parallax of the Moon. It is determined by observing the Moon from two widely separated points on Earth. Early astronomers like Hipparchus used lunar parallax to estimate the distance to the Moon, which is the closest celestial body to Earth. Modern measurements using radar and lasers have refined this distance significantly.12
Heliocentric parallax, also known as annual parallax or stellar parallax, uses Earth's orbit around the Sun as the baseline for measurement. This method is crucial for determining the distances to stars, as they are too far away to show a measurable parallax from just two points on Earth's surface. The distance to a star is inversely proportional to its measured parallax.134
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