Saturn, November 2021 | SkyNews
Saturn, November 2021 (Chris Vaughan, Starry Night Education)

Planets at a Glance: November 2021

Uranus reaches opposition; Mars climbs away from the Sun. Find out what the planets are up to this month in Planets at a Glance.


Mercury, November 2021 | SkyNews
Mercury, November 2021 (Chris Vaughan, Starry Night Education)

During the first week of November, Mercury will be completing its best morning apparition for the year for mid-Northern latitude observers, so the planet will be quite easily visible, shining at magnitude -0.85 just above the east-southeastern horizon for a short period before sunrise. Viewed in a telescope during that period, Mercury will show a waxing gibbous (i.e., more than 80-per-cent-illuminated) disk that will shrink daily from an initial 5.8 arc-seconds diameter. On November 3, the old crescent Moon will appear several finger widths above (or 4 degrees to the celestial northwest of) Mercury’s bright dot, with Virgo’s brightest star Spica positioned just to their right. The same day in mid-afternoon, the Moon will occult Mercury for about an hour; however, an experienced observer and/or a GoTo telescope will be needed to locate the pale Moon in daylight. On November 10, Mercury will pass less than a finger’s width to the upper left (or 57 arc-minutes to the celestial north) of Mars, which will appear one-tenth as bright. From mid-northern latitudes, their best viewing time will be after about 6 a.m. local time. Observers at tropical latitudes will see the two planets higher and in a darker sky. After mid-month, Mercury will be too close to the sun for observing while it approaches superior solar conjunction on November 28-29.


Venus, November 2021 | SkyNews
Venus, November 2021 (Chris Vaughan, Starry Night Education)

Venus reached its widest separation from the Sun towards the end of October, but its position well south of a canted-over evening ecliptic will keep the brilliant, magnitude -4.7 planet low in the sky for mid-northern latitude observers until later in November. Meanwhile, Southern Hemisphere observers, where the nearly vertical ecliptic has allowed the planet to sit relatively high in a dark sky, have experienced a terrific apparition. Venus’ eastward motion through the westward-shifting background stars of Sagittarius will cause the planet to set at about 8:15 p.m. local time (7:15 p.m. after Daylight Savings ends) all month long. Viewed through a telescope during November, our sister planet will show a gradually waning, less than half-illuminated phase and an apparent disk diameter that swells dramatically from 26 to 38.7 arc-seconds. On November 7, the young crescent Moon will shine several finger widths to the lower right (or 5 degrees to the celestial west) of planet Venus. Hours later, in midday on November 8, observers in parts of northeastern Asia and the western Aleutian Islands can see the Moon occult Venus — while surrounding regions will see the Moon pass very close to the planet.


Mars, November 2021 | SkyNews
Mars, November 2021 (Chris Vaughan, Starry Night Education)

As November begins, Mars will be slowly climbing away from the Sun’s glare in the east-southeastern predawn sky. From mid-Northern latitudes, the magnitude 1.65 red planet will finally become visible just above the horizon towards mid-month. A very close conjunction with Mercury on November 10 may be worthy of setting the alarm. Before the end of November, Mars will be elongated enough to briefly shine in a relatively dark sky, among the stars of Libra. On November 22, Mars will pass only 8 arc-minutes below (south of) Libra’s bright double star Zubenelgenubi.


Jupiter, November 2021
Jupiter, November 2021 (Chris Vaughan, Starry Night Education)

The earlier sunsets during November will extend our evening Jupiter-viewing time. The magnitude -2.4 planet will shine as a very bright, white dot sitting a third of the way up the southeastern sky after dusk, and then set in the west-southwest in the middle of the night. Jupiter will spend November travelling prograde eastward above the Sea-Goat’s tail in eastern Capricornus, with fainter, yellow-hued Saturn shining 16 degrees to its right (or celestial east). Views of Jupiter in amateur telescopes will show dark equatorial bands across its disk, which will shrink from 42 to 38 arc-seconds during the month. The Great Red Spot will appear for a few hours every second or third night. One or two round, black shadows of Jupiter’s Galilean satellites will cross Jupiter’s disk, sometimes with the Great Red Spot, on November 2 (for eastern Asia), 23, and 28. The bright, first quarter Moon will sit a slim palm’s width below (or 5 degrees to the celestial south of) Jupiter on November 11.


Saturn, November 2021 | SkyNews
Saturn, November 2021 (Chris Vaughan, Starry Night Education)

During November, Saturn will be observable during early evening while it travels prograde eastward through the faint stars of western Capricornus. The magnitude 0.7 ringed planet will first appear in the lower part of the southern sky after dusk, and then it will descend in the southwest towards mid-evening. Much brighter Jupiter, shining 16 degrees to Saturn’s left (east), will appear first. Viewed in a telescope, Saturn will display a mean apparent disk diameter of 16.5 arc-seconds, and its rings will subtend 38 arc-seconds. Several moons can be readily seen arrayed around the planet, especially the brightest one, Titan. Saturn’s rings will be tilting more edge-on to Earth every year until the spring of 2025. This year they are already closed enough for Saturn’s southern polar region to extend beyond them. On November 10, the nearly-half-illuminated Moon will shine a palm’s width below (or 6 degrees to the celestial southeast) of Saturn.


Uranus, November 2021 | SkyNews
Uranus, November 2021 (Chris Vaughan, Starry Night Education)

Uranus will reach opposition on November 5, making it an all-night target during November. On opposition night it will be closest to Earth for this year at a distance of 2.80 billion kilometres or 156 light-minutes. Uranus’ minimum distance from Earth will cause it to shine at a peak brightness of magnitude 5.65. It will also appear slightly larger, showing a 3.7 arc-seconds-wide disk in telescopes for a week or so centered on that date. All month long, Uranus’ small, blue-green dot will be moving slowly retrograde westwards in southern Aries, a fist’s width below (or 11.5 degrees southeast of) that constellation’s brightest stars, Hamal and Sheratan, and only a palm’s width from the star Mu Ceti to its southwest. On November 17, the very bright, nearly-full Moon will shine two thumb widths to the lower left (or 2.6 degrees to the celestial south) of Uranus — but wait for a moonless night to seek out the planet.


Neptune, November 2021 | SkyNews
Neptune, November 2021 (Chris Vaughan, Starry Night Education)

The distant, blue planet Neptune will be observable until after midnight during November. The magnitude 7.8 planet will be traveling very slowly retrograde westward among the stars of northeastern Aquarius. If the sky is very dark, Neptune can be seen in good binoculars. To locate Neptune, find the up-down grouping of five medium-bright stars Psi, Chi, and Phi Aquarii (or ψ, X, and φ Aqr). Neptune’s non-twinkling speck will sit several finger widths to the left (or 3 degrees to the celestial NNE) of the top star, Phi. Viewed in a telescope, Neptune’s apparent disk size will be 2.3 arc-seconds. Your best views will come in mid-evening, when the blue planet is highest in the south. As a bonus, the minor planet designated (2) Pallas will be positioned about a generous palm’s width to the right (or 8 degrees to the celestial southwest) of the Phi Aquarii group.

Chris Vaughan is a science writer, geophysicist, astronomer, planetary scientist and an “outreach RASCal.” He writes Astronomy Skylights, and you can follow him on Twitter at @astrogeoguy. He can also bring his Digital Starlab portable inflatable planetarium to your school or other daytime or evening event. Contact him through to tour the Universe together.