Lecture 3: Seasons and Constellations

These flashcards cover key concepts related to the Earth, seasons, celestial movements, and constellations as discussed in Lecture 3.

Constellation

A region of the sky that is defined by a set of specific stars.

Asterism

Patterns formed by stars within a constellation.

Celestial Sphere

An imaginary sphere surrounding Earth, on which all celestial objects appear to reside.

Equinox

The time when day and night are of equal length, occurring in March and September.

Solstice

The time when the sun reaches its highest or lowest point in the sky at noon, marking the start of summer and winter.

Latitude

Position north or south of the equator.

Longitude

Position east or west of the Prime Meridian.

Axial tilt

The angle between an object's rotational axis and its orbital axis, which causes seasons on Earth.

Perihelion

The point in the orbit of a celestial body where it is closest to the sun.

Aphelion

The point in the orbit of a celestial body where it is farthest from the sun.

Analemma

A figure-eight diagram that shows the position of the sun in the sky at the same time each day throughout the year.

Precession

The gradual change or shift in the orientation of an astronomical body's rotational axis.

Gravity

The force that attracts a body toward the center of the Earth, or toward any other physical body having mass.

Zenith

The point in the sky or celestial sphere directly above an observer.