Moon Phases

Moon Phases

Different shapes of the Moon, and they change with a regular pattern over a period of about 30 days. The phases of the Moon are caused by the changing positions of the Moon, Earth, and the Sun.

Rotation

A celestial body spinning on its axis

Revolution

A celestial body orbiting another

Lunar Calendar

A calendar based on the monthly cycles of the Moon's phases

Moon’s Orbit

5 degree tilt

Solar Eclipse

The Moon passes between the Sun and Earth, casting a shadow over parts of Earth and blocking the face of the Sun for observers in those locations

Lunar Eclipse

When Earth is positioned precisely between the Moon and Sun, Earth's shadow falls upon the surface of the Moon, dimming it and sometimes turning the lunar surface a striking red over the course of a few hours. Each lunar eclipse is visible from half of Earth.

Earth’s Atmosphere

A mixture of gases that surrounds and protects the Earth.

Umbra

The innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body.

Penumbra

A space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full light.

Waxing

The moon appearing larger as time goes on

Waning

The moon appearing smaller s time goes on

Gibbous

Slightly smaller than a full moon

Crescent

Slightly larger than a new moon

New Moon

None of the Moon is visible from Earth

Full Moon

The entire half of the Moon facing Earth can be seen

First Quarter Moon

The instant, approximately one week after a new moon, when one half of the moon's disk is illuminated by the sun.

Third Quarter Moon

The Moon has completed 3/4 of its orbit around the Earth. This phase of the Moon is also known as a Half Moon because only half of the Moon is visible.

Ray

Each of the lines in which light (and heat) may seem to stream from the sun or any luminous body, or pass through a small opening.

Crater

A hole on the surface of a celestial body from impact of an another; usually an asteroid or meteoroid

Maria

Large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins.

Meteoroid

Meteoroids are lumps of rock or iron that orbit the sun, just as planets, asteroids, and comets do. It would become a meteor if it entered Earth’s atmosphere.