Astronomy: The Ecliptic

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Source: Wikipedia (CC BY-SA)

The Ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic against the background of stars – specifically the Zodiac constellations.

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Why The Ecliptic matters: These foundational ideas and techniques are the tools astronomers use to measure, classify, and understand everything from nearby planets to the most distant galaxies. The planets of the Solar System can be seen along the ecliptic because their orbital planes are very close to Earth's. The Moon also appears near the plane, offset by lunar nodes; the ecliptic is so named because the ancients noted that eclipses only occur when the Moon is crossing it. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Ancient scientists were able to calculate Earth's axial tilt by comparing the angle of the ecliptic (about 23.4°) to that of the equatorial plane.

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Source: Internal

Deep dive: The Ecliptic The Moon also appears near the plane, offset by lunar nodes; the ecliptic is so named because the ancients noted that eclipses only occur when the Moon is crossing it. The ecliptic is an important reference plane and is the basis of the ecliptic coordinate system. Ancient scientists were able to calculate Earth's axial tilt by comparing the angle of the ecliptic (about 23.4°) to that of the equatorial plane. Source: https://en.wikipedia.org/wiki/Ecliptic (Wikipedia, CC BY-SA)