Tonight’s Full Moon is the Pink Moon, the Sprouting Grass Moon, the Egg Moon, the Fish Moon, the Paschal Moon (for Eastern Christianity), Hanuman Jayanti, Bak Poya, and a Supermoon.

The next full Moon will be late Monday night, April 26, 2021, appearing opposite the Sun in Earth-based longitude at 8:32 p.m. PDT. This will be the next day from the Atlantic Daylight Savings timezone eastward across Africa, Europe, Asia, and Australia to the International Date Line. Most commercial calendars are based on Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC) and will show this full Moon occurring on Tuesday, April 27, 2021. The Moon will appear full for about three days around this time, from Sunday night through Wednesday morning.

In the 1930s the Maine Farmer’s Almanac began publishing American Indian Moon names for the months of the year. According to this almanac, as the full Moon in April, this is the Pink Moon, named after the herb moss pink, also known as creeping phlox, moss phlox, or mountain phlox. The plant is native to the eastern United States and is one of the earliest widespread flowers of spring.

Other names for this Moon include the Sprouting Grass Moon, the Egg Moon, and among coastal tribes of North America, the Fish Moon, as this was when the shad swam upstream to spawn.

For Eastern Christianity (which bases its calculations on the Julian Calendar) this is the full Moon before Easter, called the Paschal Moon. This is one of the years where the different calendars used by Western and Eastern Christianity make a difference. Eastern Christianity will be celebrating Easter on Sunday, May 2, 2021. Western Christianity celebrated Easter on Sunday, April 4.

For Hindus, this is Hanuman Jayanti, the celebration of the birth of Lord Hanuman, celebrated in most areas on the full Moon day of the Hindu lunar month of Chaitra, which (in India’s time zone) is Tuesday, April 27, 2021.

For Buddhists, especially in Sri Lanka, this full Moon corresponds with Bak Poya, commemorating when the Buddha visited Sri Lanka and settled a dispute between chiefs, avoiding a war.

This Full Moon is a Supermoon

This full Moon is the first of two supermoons for 2021. The term “supermoon” was coined by astrologer Richard Nolle in 1979 and refers to either a new or full Moon that occurs when the Moon is within 90% of perigee, its closest approach to Earth. Since we can’t see a new Moon (except when it passes in front of the Sun), what has caught the public’s attention in recent decades are full supermoons, as these are the biggest and brightest full Moons for the year.

These two full Moons are virtually tied, with the full Moon on May 26, 2021, slightly closer to the Earth than the full Moon on April 26, 2021, but only by about 98 miles (157 kilometers), or about 0.04% of the distance from the Earth to the Moon at perigee.

Full Moons, New Moons, and Calendars

In many traditional lunisolar calendars, the months change with the new Moon and full Moons fall in the middle of the lunar months. This full Moon is in the middle of the third month of the Chinese calendar and Iyar in the Hebrew calendar. In the Islamic calendar, the months start with the first sighting of the waxing crescent Moon shortly after the New Moon.

This full Moon is near the middle of the holy month of Ramadan. Ramadan is honored as the month in which the Quran was revealed. Observing this annual month of charitable acts, prayer, and fasting from dawn to sunset is one of the Five Pillars of Islam.

As usual, the wearing of suitably celebratory celestial attire is encouraged in honor of the full Moon.

Summary of Upcoming Celestial Events

Here is a summary of celestial events between now and the full Moon after next (with times based on the location of NASA Headquarters in Washington):

As spring continues in the northern hemisphere the daily periods of sunlight continue to lengthen. On Monday, April 26, 2021 (the day of the full Pink Moon), morning twilight will begin at 5:14 a.m. EDT, sunrise will be at 6:16 a.m., solar noon will be at 1:05:48 p.m. when the Sun will reach its maximum altitude of 64.87 degrees, sunset will be at 7:56 p.m., and evening twilight will end at 8:59 p.m. By Wednesday, May 26, 2021 (the day of the full Moon after next), morning twilight will begin at 4:38 a.m., sunrise will be at 5:47 a.m., solar noon will be at 1:05:10 p.m. when the Sun will reach its maximum altitude of 72.37 degrees, sunset will be at 8:23 p.m., and evening twilight will end at 9:33 p.m.

On Monday evening, as evening twilight ends at 8:59 p.m. EDT, the planet Mars will appear about 38 degrees above the western horizon. The planets Venus and Mercury will have already set, but you might be able to catch them in the glow of dusk from about 30 minutes after sunset until they set in the west-northwest.

The bright star appearing closest to directly overhead will be Regulus – the heart of the lion in the constellation Leo – appearing 63 degrees above the southern horizon. Regulus is about 79 light-years from us and is one of four stars that we see as one (two binary star systems orbiting each other).

The brightest of the stars in our night sky, Sirius – the Dog Star – will appear 16 degrees above the southwestern horizon. Sirius is a binary star system about 8.6 light-years from Earth. The bright stars of the local arm of our home galaxy including the constellation Orion will appear spread along the horizon from the south-southwest towards the west.

As the lunar cycle progresses, the planet Mars and the background of stars will appear to shift toward the west, although it is actually the Earth that is moving around the Sun towards the east. Mars will appear to shift more slowly than the stars since Mars is moving in the same direction we are.

Beginning April 29, the planet Mercury will appear above the horizon in the west-northwest as evening twilight ends.

On May 12, you might be able to see the very thin, waxing crescent Moon low on the horizon in the west-northwest, appearing to the left of Venus from about 30 minutes after sunset until the pair sets about 5 minutes before evening twilight ends. However, the crescent Moon might be too thin to see, especially without binoculars or a telescope.

On May 13, the thin, waxing crescent Moon will have shifted higher in the sky to appear to the left of Mercury in the west-northwest, with Mercury setting about 47 minutes after evening twilight ends.

May 15 will be the evening when the planet Mercury will reach its highest above the horizon as evening twilight ends for this apparition, about 7 degrees above the west-northwestern horizon. Also on May 15, the waxing crescent Moon will appear in the west-northwest to the lower right of Mars, with the pair setting around midnight.

By May 16 into May 17, the waxing crescent Moon will have shifted to appear to the lower left of the bright star Pollux, with the pair setting about 3.5 hours after evening twilight ends (setting around 12:49 a.m. EDT).

Beginning May 19, the bright planet Venus will join Mercury above the horizon in the west-northwest as evening twilight ends. On May 19 into May 20, the waxing half-full Moon will appear above the bright star Regulus, with Regulus setting first early on May 20 at around 2:07 a.m.

On May 23 into May 24, the waxing gibbous Moon will appear about 7 degrees to the left of the bright star Spica, with Spica setting first on May 24 at around 3:52 a.m.

By the evening of Wednesday, May 26, 2021, the day of the full Moon after next, as evening twilight ends (at 9:33 p.m. EDT), the brightest planet visible will be Venus, appearing only 1 degree above the horizon in the west-northwest. To the upper left of Venus will be the planet Mercury, appearing 3 degrees above the horizon. The planet Mars, slightly brighter than Mercury, will appear 23 degrees above the west-northwestern horizon. The constellation Ursa Major, also known as the Big Dipper, will appear in the north close to nearly overhead. No bright star will appear close to overhead, with the closest being Arcturus at 62 degrees above the southeastern horizon.

Moonlight interference will be even worse for the less predictable Pi-Puppid meteor shower, expected to peak the next morning, Friday, April 23, 2021. These meteors are caused by debris from Comet Grigg–Skjellerup.

The annual Eta-Aquariid meteor shower is expected to be active from April 19 through May 28, peaking the morning of May 6, 2021. From the Southern Hemisphere and under ideal conditions, this meteor shower tends to peak at rates from 40 to 85 visible meteors per hour. However, the Washington area is on the northern edge of the latitudes from which we can see these meteors. This and the relatively short time between the rising of the radiant (the area in the sky from which these meteors appear to radiate out from) and when morning twilight begins will make these meteors hard to see. These meteors are caused by debris from Halley’s Comet entering our atmosphere at 148,000 miles per hour (66 kilometers per second).