Moon Phases

The moon's phases are caused by changes in the amount of illumination from the moon that is visible from the Earth's surface as the moon orbits our planet each month. There are eight distinct phases every month, four of them occurring roughly a week apart. They are: the New Moon; Waxng Crescent; First Quarter (or half-full; Waxing Gibbous; Full Moon; Waning Gibbous; Last Quarter (half-full on other side); Waning Crescent. You can read definitions for these moon phases here. When the moon is full and at its closest point to the Earth in it's orbit, it is known as a "Supermoon." Lunar eclipses occur during full moons, when the moon passes through all or part of Earth's shadow. During New Moons, the moon can cover part or all of the sun's disk, creating a solar eclipse. Learn more about the moon's phases here.

Related Topics: The Moon

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What is a blood moon?

By Elizabeth Howell

If the rays of the setting or rising sun hit the moon just right, the moon appears to turn red or ruddy-brown. This is called a blood moon.

Jupiter in visible, ultraviolet and infrared wavelengths.

Space photos: The most amazing images this week!

By Doris Elin Urrutia

See the best photos on Space.com this week.

This illustration (made using real images and data) shows the moon in shadow during the "new moon" lunar phase.

May new moon 2021: See Mercury, Venus and Mars in the moonless evening sky

By Jesse Emspak

The new moon occurs Tuesday (May 11) at 3 p.m. EDT (1900 GMT). Here's what you can see in the dark, moonless sky.

Celebrate the "Taco Moon" tonight (May 4) with a free crunchy taco from Taco Bell.

Celebrate the 'Taco Moon' with a free taco from Taco Bell tonight!

By Hanneke Weitering

The last quarter moon will shine like a big, cheesy taco in the sky tonight (May 4), and Taco Bell is celebrating the lunar phase by giving away free tacos.

The Super Pink Moon is seen over Stonehenge in Amesbury, England, during the early morning of April 27, 2021.

See the 'Super Pink Moon' of 2021 shine in these stunning photos

By Samantha Mathewson

April's full moon, called the "Super Pink Moon," wowed skywatchers on Monday (April 26) as it shone brightly in the night sky.

A supermoon rises behind the U.S. Capitol, Monday, March 9, 2020, in Washington., D.C.

The Super Pink Moon of 2021 rises tonight, but it won't look pink

By Tereza Pultarova

If you have a clear sky tonight, look up! Today’s full moon will be bigger and brighter than usual as the Earth’s companion makes a close approach to the planet during its full moon phase.

April Full Moon 2021: 'Super Pink Moon' rises Monday

By Jesse Emspak

The full moon of April, called the Pink Moon, occurs Monday, April 26 at 11:32 p.m. EDT (0332 GMT on Tuesday, April 27). It will also be a "supermoon."

A photo of a nearly full moon. The image was taken one day prior to the supermoon, or a moon that appears larger due to being the closest to Earth in its orbit.

2021 Full Moon Calendar

By Kimberly Hickok

The full moon happens about once a month. Find out when.

The full moon looks massive as it sets behind the Very Large Telescope in Chile's Atacama Desert, in this photo released on June 7, 2010.

The Paschal full moon of 2021 rises tonight to make way for Easter

By Joe Rao

Palm Sunday, March 28 brings us the first full moon of the new spring season: the Paschal full moon.

The full moon of March, called the Worm Moon, will occur on Wednesday, March 20, at 9:43 p.m. EDT (0143 GMT on March 21), just under four hours after the vernal equinox.

March full moon 2021: Catch the big 'Worm Moon' (and 1st 'supermoon' of the year) on Sunday

By Jesse Emspak

The full moon of March, called the Worm Moon, will occur on Sunday (March 28), two days before the moon reaches perigee, its closest point to Earth.

The full moon of February, called the Snow Moon, occurs Saturday, Feb. 27, 3:17 a.m. EST (0817 GMT).

February full moon 2021: See the 'Snow Moon' with Mars this weekend

By Jesse Emspak

The full moon of February, called the Snow Moon, occurs Saturday, Feb. 27, 3:17 a.m. EST (0817 GMT).

The moon and Mars will appear in a conjunction on the night of Feb. 18, 2021.

Celebrate NASA's Perseverance Mars rover landing by spotting the Red Planet near the moon tonight

By Doris Elin Urrutia

Mars may not be ready to escape the spotlight just yet, even after receiving its third Earthly mission this month.

Full moon names (and more) for 2021

By Joe Rao

Here is a list of common full moon names, dates and times in 2021, beginning with the "Wolf Moon" in January, to the "Cold Moon" in December.

The full moon of January, known as the Full Wolf Moon, arrives Thursday, Jan. 28, at 2:16 p.m. EST (1916 GMT).

January full moon 2021: The 'Wolf Moon' rises with winter constellations

By Jesse Emspak

The full moon of January, called the Wolf Moon, will occur on Thursday, Jan. 28, at 2:16 p.m. EST (1916 GMT)

People go to bed later and sleep fewer hours the night before a full moon, and menstrual cycles seem to temporarily synchronize with moon cycles, scientists have found in two new studies.

The full moon may influence sleep and menstrual cycles, scientists say

By Chelsea Gohd

People go to bed later and sleep fewer hours the night before a full moon, and menstrual cycles seem to temporarily synchronize with moon cycles, scientists have found in two new studies.