Astronomy Basics Quiz

A group of stars that form a recognizable pattern in the night sky. These stars are often unrelated and far apart.

An imaginary sphere that surrounds the Earth, onto which we project the stars, planets, and other celestial objects.

The apparent path of the Sun across the celestial sphere throughout the year. It is caused by the Earth's orbit around the Sun.

A band of light in the night sky caused by the billions of stars in our Milky Way galaxy.

A pattern of stars that is not officially recognized as a constellation. For example, the Big Dipper is an asterism within the constellation Ursa Major.

Ancient civilizations used astronomy for timekeeping, navigation, and religious and cultural purposes.

The tilt of Earth's axis at 23.5 degrees is the reason why the celestial equator does not coincide with the ecliptic.

Some stars appear brighter than others, and they move in predictable paths across the sky.

The half of the celestial sphere visible from a specific location on Earth.

The angular distance of a celestial object above the horizon, measured in degrees.

The direction of a celestial object relative to North, measured in degrees clockwise from North.

The angle an object appears to span in your field of view, as projected on the celestial sphere. It's measured in degrees.

Stars that never set below the horizon from a particular location on Earth, due to Earth's tilt.

The daily rotation of the celestial sphere, causing stars to appear to move from east to west.

The latitude of an observer on Earth determines which stars are visible, which stars are circumpolar, and which stars are never seen.

The two points in Earth's orbit where one hemisphere receives the most or least sunlight.

The two points in Earth's orbit where both hemispheres receive equal amounts of sunlight.

The wobble of Earth's axis of rotation, causing a slow, cyclical change in the direction it points.

The point in the Moon's orbit closest to Earth.

The point in the Moon's orbit farthest from Earth.

The dark, smooth areas on the Moon formed by volcanic eruptions.

The apparent change in the Moon's size when it's full and at its perigee.

The angle between Earth's axis of rotation and its orbital plane around the Sun.

The imaginary point in the sky directly above the Earth's North Pole. All stars appear to rotate around this point.

The position of the North Celestial Pole in the sky directly corresponds to your latitude. So, if the NCP is 45 degrees above the horizon, you're at 45 degrees latitude.

The constellations that the Sun appears to pass through during its yearly journey along the ecliptic. These constellations are visible in different parts of the year.

The point in Earth's orbit where it is closest to the Sun. This occurs around January 3rd.

The point in Earth's orbit where it is farthest from the Sun. This occurs around July 4th.

The tilt of Earth's axis at 23.5 degrees is the main reason for different seasons. It causes the amount of sunlight received on each side of the Earth to vary.

The Moon rotates on its axis at the same rate as it orbits the Earth, which is why we always see the same side.

The Moon's path around the Earth is tilted at an angle, causing two points where the Moon crosses the Earth's orbital plane.

An event when the Moon passes between the Sun and Earth, blocking out the Sun's light completely or partially for a short time.

An event when the Earth passes between the Sun and Moon, casting a shadow on the Moon and making it appear reddish.

Even though the Moon is smaller than the Sun, it appears to be the same size in the sky because it's much closer to Earth.

The apparent backward motion of a planet against the background stars, caused by the differing speeds of their orbits.

The planets do not move steadily eastward across the sky, they can appear to reverse course for a few weeks or a month.

The apparent change in position of an object due to the observer's motion. It's like looking at an object from different positions, making it appear to shift.

The lack of observable parallax for stars in ancient times was a strong argument against the idea of a stationary Earth.

Objects further away appear to move slower due to their larger distance. This explains why ancient astronomers couldn't observe parallax for stars.

The apparent path of the Sun across the celestial sphere throughout the year. It is caused by Earth's orbit around the Sun.

The imaginary sphere that surrounds Earth, onto which we project the stars, planets, and other celestial objects.

Ancient astronomers saw that planets moved differently than stars. This led them to think that planets were somehow connected to Earth.

The ability to see the celestial sphere from a particular location on Earth is determined by the observer's latitude

Stars that never set below the horizon from a particular location on Earth due to the tilt of Earth's axis.