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Mercury after sunset: Greatest elongation is August 27

Mercury as a white dot on a twilight sky with two other white dots nearby for Spica and Arcturus.
Mercury reaches its greatest distance from the sun on August 27, 2022. From the Northern Hemisphere it hugs the horizon shortly after sunset. The bright star Spica and brilliant orange star Arcturus are nearby.

Mercury is having a great evening apparition in August 2022 … for the Southern Hemisphere. For us in the Northern Hemisphere, Mercury appears low in the evening twilight horizon throughout August, tough to see. But a careful search with binoculars might bring the little planet into view.

Where to look: Look for Mercury in the sunset direction, as soon as the sky begins to darken. Northern Hemisphere observers: Try sweeping for Mercury with binoculars. It might surprise you, and pop into view.
When to look: Mercury begins this evening apparition in late July. It’ll disappear again by mid-September.
Greatest elongation is 16 UTC on August 27, 2022. At greatest elongation, Mercury is farthest from the sunset for this evening apparition, 27 degrees from the sun in the evening sky.
Note: As the innermost planet, Mercury is tied to the sun in our sky. As a result, it never ventures very far above the horizon after sunset. As soon as the sun disappears below your horizon, the clock starts ticking. So, will you see the glowing point of light that is Mercury before it follows the setting sun?

Mercury as a white dot with two other white dots nearby for Spica and Arcturus.
Mercury is much easier to see in the Southern Hemisphere in August 2022. It reaches its greatest distance from the sun (greatest elongation) on August 27, when you’ll find it below the bright star Spica. The brilliant orange star Arcturus will be shining higher in the sky than Mercury.

At greatest elongation in August 2022:

– Mercury’s distance from sun on the sky’s dome is 27 degrees.
– Mercury’s elevation in our Northern Hemisphere sky doesn’t improve, as the planet approaches greatest elongation in late August. That’s because the ecliptic (path of the sun, moon and planets) lies at such a narrow angle to the evening horizon at this time of year. So Mercury’s movement away from the sun carry it southward along the horizon, instead of upward.
– Mercury shines at magnitude 0.2.
– Through a telescope, Mercury appears about 53% illuminated, in a waxing gibbous phase, 7.2 arcseconds across.

For precise sun and Mercury rising times at your location:

Old Farmer’s Almanac (U.S. and Canada)
Timeanddate.com (worldwide).
Stellarium (online planetarium program)

Mercury events in 2022 and 2023

Aug 27, 2022: Greatest elongation (evening)
Sep 23, 2022: Inferior conjunction (races between Earth and sun)
Oct 8, 2022: Greatest elongation (morning)
Nov 8, 2022: Superior conjunction (passes behind sun as seen from Earth)
Dec 21, 2022: Greatest elongation (evening)
Jan 7, 2023: Inferior conjunction (races between Earth and sun)
Jan 30, 2023: Greatest elongation (morning)
Mar 17, 2023: Superior conjunction (passes behind sun from Earth)
Apr 11, 2023: Greatest elongation (evening)
May 1, 2023: Inferior conjunction (races between Earth and sun)
May 29, 2023: Greatest elongation (morning)
Jul 1, 2023: Superior conjunction (passes behind sun from Earth)
Aug 10, 2023: Greatest elongation (evening)
Sep 6, 2023: Inferior conjunction (races between Earth and sun)
Sep 22, 2023: Greatest elongation (morning)
Oct 20, 2023: Superior conjunction (passes behind sun from Earth)
Dec 4, 2023: Greatest elongation (evening)
Dec 22, 2023: Inferior conjunction (races between Earth and sun)

Heliocentric view of Mercury August 2022

Circle with sun at center, planets around, and zodiac names on outer edge.
View larger. | Heliocentric view of the solar system, August 2022. Chart via Guy Ottewell.

A comparison of elongations

Not all of Mercury’s greatest elongations are created equal. Indeed, some are greater than others. Ultimately, the farthest from the sun that Mercury can ever appear on the sky’s dome is about 28 degrees. The least distance, comparatively, is around 18 degrees.

Also, elongations are better or worse depending on the time of year they occur.

In the autumn for either hemisphere, the ecliptic – or path of the sun, moon and planets – makes a narrow angle to the horizon in the evening. But it makes a steep slant, nearly perpendicular, in the morning. So, in autumn from either hemisphere, morning elongations of Mercury are best. Then, Mercury appears higher above the horizon and farther from the glow of the sun. Evening elongations in autumn are harder to see, however.

But, In the spring for either hemisphere, the situation reverses. The ecliptic and horizon meet at a sharper angle on spring evenings and a narrower angle on spring mornings. So, in springtime for either hemisphere, evening elongations of Mercury are best. Meanwhile, morning elongations in springtime are harder to see.

Chart with light blue and gray waves, black annotations, comparing Mercury elongatons in 2022.
View larger. | Mercury elongations compared. Gray areas represent evening apparitions (eastward elongation). Blue areas represent morning apparitions (westward elongation). The top figures are the maximum elongations, reached at the top dates shown beneath. Curves show the altitude of the planet above the horizon at sunrise or sunset, for latitude 40 degrees north (thick line) and 35 degrees south (thin). Maxima are reached at the parenthesized dates below (40 degrees north bold). Chart via Guy Ottewell’s 2022 Astronomical Calendar.

Photos from our community

Sunset with trees and label of Mercury on small dot.
View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, took this image on April 23, 2022. Joel wrote: “While the early morning planetary alignment garners attention, lonely little Mercury is making an appearance in our evening skies. Despite being elusive, it was easy to see without optical aid once sighted. Mercury will remain a pleasant addition to our evening skies as it reaches its greatest eastern elongation on April 29.” Thank you, Joel!
Lifeguard tower in the foreground, crescent moon and Mercury in a twilight sky.
View at EarthSky Community Photos. | Chix RC captured this image on January 3, 2022, from Hermosa Beach, California. See Mercury to the upper right of the crescent? Chix wrote: “A faint young moon at 1% illumination and Mercury.” Thank you, Chix!
Mercury and Mars close together in dim sunset sky over wooded hills.
Peter Lowenstein of Mutare, Zimbabwe caught Mercury and Mars in the evening twilight on August 18, 2021. Thank you, Peter!
Crescent moon, two labeled dots in blue and orange sky over a lighted suspension bridge.
View at EarthSky Community Photos. | Alexander Krivenyshev of the website WorldTimeZone.com captured this photo of the moon together with Mercury and Venus on May 13, 2021, from Newport, Rhode Island. Thank you, Alexander!

Submit your photos to EarthSky here.

Some resources to enjoy

Read about greatest elongations, superior and inferior conjunctions: Definitions for stargazers

See the moon phase for every day in 2022. EarthSky lunar calendars now available! Going fast!

Bottom line: Mercury is currently visible during its evening apparition. Look in the sunset direction, as the sky is darkening. The planet reaches greatest elongation on August 27, 2022.

The post Mercury after sunset: Greatest elongation is August 27 first appeared on EarthSky.

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