Welcome to the third in our four part series detailing the major events of 2021’s astronomical calendar. This guide will help you to set your fall 2021 stargazing itinerary, providing a detailed listing of what each month’s sky has to offer. We began in March of 2021, when astronomical spring is ushered in with the Vernal Equinox on March 20th and continued with Part 2, when astronomical summer began with the Estival Solstice. Now, with the Autumnal Equinox opening the season on September 22nd, we will continue to follow the celestial rotation into fall.
This guide aims to provide you with precise dates that allow for easiest viewings of celestial objects from the vantage of North America, including the stages of the Moon, the planets, meteor showers, and the best times to view a number of highly sought after deep sky objects. For further details to help in locating these objects with their specific longitudes, there are a number of star-finder resources online that we suggest you view in preparation for viewing. Get your personal calendar ready and setup your new telescope so that you can plan out your amateur astronomy schedule for fall.
SEPTEMBER
The Autumnal Equinox
On September 22nd, astronomical fall will begin with the Autumnal Equinox, named so because the path of the sun rests on the equator, providing for an equal division between daylight and nighttime hours. From here, the Northern Hemisphere will begin to tilt away from the Sun, providing for shorter days and longer nights, which makes for some of the best stargazing.
The Moon: Harvest Moon
The Full Moon on September 20th will appear as what’s known at the Harvest Moon, as it typically coincides with harvest festivals. The Harvest Moon is the only Moon name designation that changes months, occurring in October once every three years, as the name is relevant to whatever Full Moon occurs closest to the September Equinox. Other years, September’s Full Moon is known as the Corn Moon. The Moon will appear in Last Quarter on September 28th, when the lunar terminator reveals the best time to view and photograph the left half of the visible Moon.
Uranus
Uranus will come into conjunction with the Moon on September 24th, both objects appearing within the constellation of Aries.
Daytime Sextantid Meteor Shower
Occurring between the dates of September 9th to October 9th, and peaking on September 27th, the Daytime Sextantid Meteor Shower radiates out from the constellation Sextans. It is not known what object is responsible for the shed of the meteors.
OCTOBER
The Moon: Hunter’s Moon
October 6th sees the birth of the New Moon, when the cycle of the Moon’s phases begins anew. This is the best time to view and photograph the night sky, as the Moon’s illumination is at its lowest, granting the clearest views of the spiraling arms of the Milky Way. On October 13th, the Moon will be at First Quarter, revealing the right half of the visible Moon. The Full Moon on October 20nd will appear as what’s known at the Hunter’s Moon, as this month is usually spent hunting in preparation for winter’s food stores. The Moon will appear in Last Quarter on October 28th, when the lunar terminator reveals the best time to view and photograph the left half of the visible Moon.
Asteroid 40 Harmonia will reach opposition on October 1st, and can be visible in the constellation of Cetus. Considered a minor planet, 40 Harmonia received its name in 1856 to honor the resulting peace and harmony brought on by the end of the Crimean War.
M110
M110 is a dwarf elliptical galaxy that will peak in height on the horizon on October 2nd. It can be located in the constellation of Andromeda, and is the brightest satellite galaxy of the Andromeda Galaxy.
M32
Also known as Le Gentil, M32 is an elliptical dwarf galaxy that will peak in height on the horizon on October 3rd. It can be located in the constellation of Andromeda, and is the second brightest satellite galaxy of the Andromeda Galaxy. M32 is considered an early type galaxy, and it is speculated that M32 was once a larger spiral galaxy that was compressed and stripped by the much larger Andromeda Galaxy.
M31
Also known as the infamous Andromeda Galaxy, M31 is a barred spiral galaxy that will peak on the horizon on October 3rd. It can be located in the constellation of Andromeda. The Andromeda Galaxy is the closest major galaxy to our own Milky Way Galaxy, with which it is expected to collide in about 4.5 billion years.
NGC 253
Also known as the Sculptor Galaxy, NGC 253 is an intermediate spiral galaxy that will peak in height on the horizon on October 4th. It can be located in the constellation of Sculptor, and is considered a starburst galaxy, meaning that it is experiencing a period of intense star formation. Unfortunately, it cannot be seen by the northernmost parts of North America.
October Camelopardalid Meteor Shower
Occurring between the dates of October 5th to October 6th, and peaking on October 5th, the October Camelopardalid Meteor Shower radiates out from the constellation of Draco.
Draconid Meteor Shower
Occurring between the dates of October 6th to October 10th, and peaking on October 8th, the Draconid Meteor Shower radiates out of the constellation of Draco. The shower was created by the shed of Comet Giacobini-Zinner.
Venus
Venus will come into conjunction with the Moon on October 9th, both objects appearing within the constellation of Scorpius. Venus will reach its point of greatest eastern elongation from the Sun on October 29th. Venus reaches dichotomy on October 28th, where it will be lit similar to the way the Moon is during its Quarter Phases
Southern Taurid Meteor Shower
Occurring between the dates of September 10th to November 20th, and peaking on October 10th, the Southern Taurid Meteor Shower radiates out of the constellation of Cetus. The shower was created by the shed of Comet Encke, which is believed to be the remnant of a much larger comet that was destroyed 20,000 to 30,000 years ago, leaving behind the largest dust and debris stream that the Earth passes through, accounting for the extended length of the shower.
Delta Aurigid Meteor Shower
Occurring between the dates of October 10th to October 18th, and peaking on October 11th, the Delta Aurigid Meteor Shower radiates out of the constellation of Auriga. Considered a minor meteor shower, it is not known what object is responsible for the shed of the meteors.
Saturn
Saturn will come into conjunction with the Moon on October 14th, both objects appearing within the constellation of Capricornus.
Jupiter
Jupiter will come into conjunction with the Moon on October 15th, both objects appearing within the constellation of Capricornus.
M33
Also known as the Triangulum Galaxy, M31 is a spiral galaxy that will peak on the horizon on October 16th. It can be located in the constellation of Triangulum. It is the third largest of the Local Group of galaxies, behind the Milky Way and Andromeda, and is speculated to either be a satellite of the Andromeda Galaxy or to be on a collision course with the galaxy.
Eris
The dwarf planet Eris will reach opposition on October 17th, reaching its highest point on the horizon in the constellation of Cetus. Initially designated the Solar System’s tenth planet, Eris is the second-largest known dwarf planet in the Solar System, and has one known moon, Dysnomia.
Epsilon Geminid Meteor Shower
Occurring between the dates of October 14th to October 27th, and peaking on October 18th, the Epsilon Geminid Meteor Shower radiates out of the constellation of Gemini. It is not known what object is responsible for the shed of the meteors, although Comet Ikeya is suspected.
Orionid Meteor Shower
Occurring between the dates of October 2nd to November 7th, and peaking on October 21st, the Orionid Meteor Shower radiates out from between the constellations of Orion and Gemini. The shower was created by the shed of Halley’s Comet, and is the largest meteor shower associated with the comet.
Uranus
Uranus will come into conjunction with the Moon on October 21st, both objects appearing within the constellation of Aries.
Mercury
Mercury will reach dichotomy, where it will be lit similar to the way the Moon is during its Quarter Phases, on October 23rd. On October 24th it will reach its point of greatest western elongation from the Sun, and the following day, on October 25th, it will reach its highest point above the horizon. This makes it the best time to observe and photograph the first planet from the Sun.
Leonis Minorid Meteor Shower
Occurring between the dates of October 19th to October 27th, and peaking on October 24th, the Leonis Minorid Meteor Shower radiates out of the constellation of Leo Minor. The shower was created by the shed of Comet C/1739 K1, and is a relatively light shower.
NGC 869 & NGC 884
When paired together NGC 869 and NGC884 are known as the Double Cluster, and are a pair of open star clusters that peak in height on the horizon on October 27th. They can be located between the constellations of Perseus and Cassiopeia.
NOVEMBER
The Moon: Beaver Moon
November 4th sees the birth of the New Moon, when the cycle of the Moon’s phases begins anew. This is the best time to view and photograph the night sky, as the Moon’s illumination is at its lowest, granting the clearest views of the spiraling arms of the Milky Way. This particular New Moon will be a Super New Moon, as the Moon is at its closest point to Earth in its rotation, appearing 7% larger than average. On November 11th, the Moon will be at First Quarter, revealing the right half of the visible Moon. The Full Moon on November 19th will appear as what’s known at the Beaver Moon, in honor of the dam building critters that typically begin preparing for winter around this time. The Beaver Moon will also undergo a Partial Lunar Eclipse the same night, and coincidentally will be what’s known as a Micro Full Moon, when the Moon will be at apogee, or its furthest point from the Earth, appearing 7% smaller than average. The Moon will appear in Last Quarter on November 27th, when the lunar terminator reveals the best time to view and photograph the left half of the visible Moon.
Comet 67P/Churyumov-Gerasimenko
Comet Churyumov-Gerasimenko will reach perihelion, or its closest approach to the Sun, on November 1st. It can be located in the constellation of Gemini. Comet Churyumov-Gerasimenko will reach its point of greatest brightness, marking the best time to photograph and view it, on November 8th. As it moves into the constellation of Gemini, Comet Churyumov-Gerasimenko will reach its perigee, or closest approach to the earth on November 13th. A member of the Jupiter Family of comets, and originally from the Kuiper belt, Comet Churyumov-Gerasimenko comes round every six and a half years, and was the first comet to be landed on by the Comet Lander Philae in 2014.
Uranus
Uranus will reach opposition on November 4th, appearing within the constellation of Aries. This is the best time to photograph the ice giant, which is the seventh planet from our Sun.
Venus
Venus will come into conjunction with the Moon on November 8th, both objects appearing within the constellation of Sagittarius.
Saturn
Saturn will come into conjunction with the Moon on November 10th, both objects appearing within the constellation of Capricornus.
Jupiter
Jupiter will come into conjunction with the Moon on November 11th, both objects appearing within the constellation of Capricornus.
Northern Taurid Meteor Shower
Occurring between the dates of October 20th to December 10th, and peaking on November 12th, the Northern Taurid Meteor Shower radiates out of the constellation of Taurus. The shower was created by the shed of Asteroid 2004 TG10, suspected to be a fragment of Comet Encke, and which is considered a potentially hazardous asteroid of the Apollo Group of Near Earth Asteroids.
M45
Also known as the Pleiades Star Cluster, or the Seven Sisters, M45 is an open star cluster that will peak on the horizon on November 12th. It can be located between the three constellations of Taurus, Perseus, and Aries. M45 is one of the nearest star clusters to Earth and is the nearest Messier object. When paired with the open star cluster Hyades, which is the nearest open star cluster to Earth, M45 creates the Golden Gate of the Ecliptic.
Partial Lunar Eclipse
On November 19th the Moon will undergo a Partial Lunar Eclipse. This sees the Earth come between the Sun and Moon, and Earth’s shadow cast a shadow over the lunar surface.
Alpha Monocerotid Meteor Shower
Occurring between the dates of November 15th to November 25th, and peaking on November 21st, the Alpha Monocerotid Meteor Shower radiates out of the constellation of Canis Minor. The shower was created by the shed of Comet Mellish, and features some of the fastest moving meteors that can be seen.
Ceres
Dwarf planet Ceres will reach opposition on November 27th, reaching its highest point on the horizon in the constellation of Taurus. This will be one of the best times to photograph the dwarf planet, which is the smallest of the dwarf planets but the largest object in the Main Asteroid Belt.
November Orionid Meteor Shower
Occurring between the dates of November 13th to December 6th, and peaking on November 28th, the November Orionid Meteor Shower radiates out of the constellation of Orion.
DECEMBER
The Moon: Cold Moon
December 4th sees the birth of the New Moon, when the cycle of the Moon’s phases begins anew. This is the best time to view and photograph the night sky, as the Moon’s illumination is at its lowest, granting the clearest views of the spiraling arms of the Milky Way. This particular New Moon will be a Super New Moon, as the Moon is at its closest point to Earth in its rotation, appearing 7% larger than average. On December 11th, the Moon will be at First Quarter, revealing the right half of the visible Moon. The Full Moon on December 19th will appear as what’s known at the Cold Moon, in reference to the winter season. This particular Cold Moon will also appear as a Micro Full Moon, when the Moon will be at apogee, or its furthest point from the Earth, appearing 7% smaller than average. The Moon will appear in Last Quarter on December 27th, when the lunar terminator reveals the best time to view and photograph the left half of the visible Moon.
December Phi Cassiopeiid Meteor Shower
Occurring between the dates of December 1st to December 8th, and peaking on December 6th, the December Phi Cassiopeiid Meteor Shower radiates out of the constellation of Andromeda.
Venus
Venus will come into conjunction with the Moon on December 6th, both objects appearing within the constellation of Sagittarius. This conjunction also coincides with when Venus will reach its highest point in the evening sky. On December 7th, Venus will reach its point of greatest brightness.
Puppid-Velid Meteor Shower
Occurring between the dates of December 1st to December 15th, and peaking on December 7th, the Puppid-Velid Meteor Shower radiates out of the constellation of Vela.
Saturn
Saturn will come into conjunction with the Moon on December 7th, both objects appearing within the constellation of Capricornus.
Monocerotid Meteor Shower
Occurring between the dates of December 5th to December 20th, and peaking on December 9th, the Monocerotid Meteor Shower radiates out of the constellation of Monoceros.
Jupiter
Jupiter will come into conjunction with the Moon on December 9th, both objects appearing within the constellation of Capricornus.
Asteroid 44 Nysa
Asteroid 44 Nysa will reach opposition on December 10th, and can be visible in the constellation of Taurus. Considered a minor planet, Asteroid 44 Nysa is the brightest member of the Nysian Asteroid Family, and is the largest Class-E Asteroid known to man.
Sigma Hydrid Meteor Shower
Occurring between the dates of December 3rd to December 15th, and peaking on December 12th, the Sigma Hydrid Meteor Shower radiates out of the constellation of Hydra. This is a minor and relatively faint shower.
Geminid Meteor Shower
Occurring between the dates of December 4th to December 17th, and peaking on December 14th, the Geminid Meteor Shower radiates out of the constellation of Gemini. The shower was created by the shed of Asteroid 3200 Phaethon, which orbits closer to the Sun than any other asteroid. The Geminid Meteor Shower is one of the strongest showers of each year, featuring slow-moving meteors, and has been increasing in intensity in recent years.
NGC 1981
NGC 1981 is an open star cluster that will peak on the horizon on December 15th. It can be located in the constellation of Orion.
Comae Berenicid Meteor Shower
Occurring between the dates of December 12th to December 23rd, and peaking on December 16th, the Comae Berenicid Meteor Shower radiates out of the constellation of Leo.
December Leonis Minorid Meteor Shower
Occurring between the dates of December 5th to February 4th, and peaking on December 19th, the December Leonis Minorid Meteor Shower radiates out of the constellation of Leo Minor.
