Mercury at greatest evening elongation, start watching now


Mercury on December 4, Northern Hemisphere.
On December 4, Mercury reaches its furthest angular distance from the sun, known as greatest eastern elongation. On this date, it lies low in the southwest. Chart via John Jardine Goss/ EarthSky.

Mercury will reach its greatest elongation on December 4, 2023.

Mercury in November and December 2023

Where to look: Look west, in the sunset direction – shortly after sunset – for Mercury. The sun’s innermost planet may be challenging even for the more favored view from the Southern Hemisphere.
Greatest elongation: Mercury is farthest from the sun – at greatest elongation – at 14 UTC on December 4, 2023 (8 a.m. CDT on December 4). It’s 21 degrees from the sun.
Brightness: Mercury will emerge in the evening sky the second week of November at -0.5 magnitude but it’s at a far southerly declination so it’ll be difficult for the Northern Hemisphere. At greatest elongation, Mercury shines at magnitude -0.3, making it brighter than most stars. But, after greatest elongation, the innermost planet will rapidly fade as it sweeps toward Earth. It’ll probably disappear by mid-month and will reach inferior conjunction – when it will pass between Earth and the sun – on December 22.
Through a telescope: Mercury will appear about 62% illuminated, at greatest elongation. It’ll measure 6.7 arcseconds across.
Constellation: Mercury will lie in front of the constellation Sagittarius the Archer at this elongation. But most of stars of this constellation will be lost in the twilight.
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. So as soon as the sun disappears below your horizon, your clock starts ticking. Will you see the glowing point of light that is Mercury before it drops below the horizon, following the setting sun?

The 2024 lunar calendars are here! Best Christmas gifts in the universe! Check ’em out here.

Circles showing Earth and Mercury orbits around the sun and 2 red lines from the Earth to Mercury and the sun.
At greatest elongation, Mercury is on one side of the sun and is at its greatest distance from the sun on our sky’s dome. Mercury reaches greatest eastern (evening) elongation from the sun on December 4, 2023. And it is 21 degrees from the sun in the evening sky. Chart via John Jardine Goss/ EarthSky.

Finder charts for November Northern Hemisphere evenings

White dots for the moon over 2 days and Mercury in November along a green ecliptic line.
The slender waxing crescent moon will hang low in the southwest shortly after sunset on the evenings of November 14 and 15, 2023. Binoculars will help spot Mercury near the moon in the bright twilight on November 14, 2023. Chart via John Jardine Goss/ EarthSky.
White dot for Mercury and the Teapot asterism in November along a green ecliptic line.
For viewers in the Northern Hemisphere, Mercury will lie just above the horizon in the bright twilight shortly after sunset in the second half of November 2023. The Teapot asterism of Sagittarius is nearby but it will be difficult to spot in the bright evening twilight. Chart via John Jardine Goss/ EarthSky.

Finder charts for November Southern Hemisphere evenings

White dot for Mercury and a red dot for Antares in November along a green ecliptic line.
As viewed from the Southern Hemisphere, Mercury will appear low in the west shortly after sunset after November 10, 2023. Look for the bright red star Antares nearby. Chart via John Jardine Goss/ EarthSky.
White dots for the moon and Mercury, plus a red dot for Antares along a green ecliptic line.
As viewed from the Southern Hemisphere, the waxing crescent moon will form an attractive triangle with Mercury and Antares shortly after sunset on November 14, 2023. Chart via John Jardine Goss/ EarthSky.
White dots for Mercury and the moon with a red dot for Antares in November along a green ecliptic line from the Southern Hemisphere.
As viewed from the Southern Hemisphere, Mercury will pass the star Antares on November 16, 2023. Chart via John Jardine Goss/ EarthSky.
White dot for Mercury and the Teapot asterism in November along a green ecliptic line.
During the second half of November 2023, Mercury will lie low in the west below the Teapot asterism of Sagittarius shortly after sunset. Chart via John Jardine Goss/ EarthSky.

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 2023 and 2024

Note: Times are in UTC

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)

Jan 12, 2024: Greatest elongation (morning)
Feb 28, 2024: Superior conjunction (passes behind sun from Earth)
Mar 24, 2024: Greatest elongation (evening)
Apr 11, 2024: Inferior conjunction (races between Earth and sun)
May 9, 2024: Greatest elongation (morning)
Jun 14, 2024: Superior conjunction (passes behind sun from Earth)
Jul 22, 2024: Greatest elongation (evening)
Aug 19, 2024: Inferior conjunction (races between Earth and sun)
Sep 5, 2024: Greatest elongation (morning)
Sep 30, 2024: Superior conjunction (passes behind sun from Earth)
Nov 16, 2024: Greatest elongation (evening)
Dec 5, 2024: Inferior conjunction (races between Earth and sun)
Dec 25, 2024: Greatest elongation (morning)

Heliocentric view of Mercury December 2023

Circle with sun at center, planets around, and zodiac names on outer edge.
View larger. | Heliocentric view of solar system, December 2023. Chart via Guy Ottewell.

A comparison of elongations

The farthest from the sun that Mercury can ever appear on the sky’s dome is about 28 degrees. And the least distance is around 18 degrees.

Also, elongations are better or worse depending on the time of year they occur. So in 2023, the Southern Hemisphere had the best evening elongation of Mercury in August 2023. And the Northern Hemisphere had the best evening apparition in April.

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. That’s when Mercury appears higher above the horizon and farther from the glow of the sun. However, evening elongations in autumn are harder to see.

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 row of alternating light blue and gray arcs, each with a date and height in degrees.
View larger. | Mercury elongations compared. Here, gray areas represent evening apparitions (eastward elongation). And 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 2023 Astronomical Calendar. Used with permission.

More Mercury elongation comparisons for 2023

Annotated sky chart with arced rows of dots and dashed line for celestial equator.
View larger. | Mercury’s greatest evening elongations in 2023 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell. Used with permission.
Sky chart with constellations, planet paths, and objects labeled.
View larger. | Mercury’s greatest evening elongations in 2023 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell. Used with permission.

Mercury photos from our community

Sunset with tall narrow trees and label of Mercury on small dot in blue twilight sky.
View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, took this image on April 23, 2022. Joel wrote: “Lonely little Mercury is making an appearance in our evening skies. Despite being elusive, it was easy to see without optical aid once sighted.” Thank you, Joel!
Silhouette of 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!
Crescent moon, 2 labeled dots (Mercury and Venus) 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!

Bottom line: Mercury is visible in the evening sky. Look in the west as the sky is darkening. The planet will reach its greatest elongation overnight on December 4, 2023.

Submit your photos to EarthSky here.

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

The post Mercury at greatest evening elongation, start watching now first appeared on EarthSky.



from EarthSky https://ift.tt/Ik0Dqjg
Mercury on December 4, Northern Hemisphere.
On December 4, Mercury reaches its furthest angular distance from the sun, known as greatest eastern elongation. On this date, it lies low in the southwest. Chart via John Jardine Goss/ EarthSky.

Mercury will reach its greatest elongation on December 4, 2023.

Mercury in November and December 2023

Where to look: Look west, in the sunset direction – shortly after sunset – for Mercury. The sun’s innermost planet may be challenging even for the more favored view from the Southern Hemisphere.
Greatest elongation: Mercury is farthest from the sun – at greatest elongation – at 14 UTC on December 4, 2023 (8 a.m. CDT on December 4). It’s 21 degrees from the sun.
Brightness: Mercury will emerge in the evening sky the second week of November at -0.5 magnitude but it’s at a far southerly declination so it’ll be difficult for the Northern Hemisphere. At greatest elongation, Mercury shines at magnitude -0.3, making it brighter than most stars. But, after greatest elongation, the innermost planet will rapidly fade as it sweeps toward Earth. It’ll probably disappear by mid-month and will reach inferior conjunction – when it will pass between Earth and the sun – on December 22.
Through a telescope: Mercury will appear about 62% illuminated, at greatest elongation. It’ll measure 6.7 arcseconds across.
Constellation: Mercury will lie in front of the constellation Sagittarius the Archer at this elongation. But most of stars of this constellation will be lost in the twilight.
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. So as soon as the sun disappears below your horizon, your clock starts ticking. Will you see the glowing point of light that is Mercury before it drops below the horizon, following the setting sun?

The 2024 lunar calendars are here! Best Christmas gifts in the universe! Check ’em out here.

Circles showing Earth and Mercury orbits around the sun and 2 red lines from the Earth to Mercury and the sun.
At greatest elongation, Mercury is on one side of the sun and is at its greatest distance from the sun on our sky’s dome. Mercury reaches greatest eastern (evening) elongation from the sun on December 4, 2023. And it is 21 degrees from the sun in the evening sky. Chart via John Jardine Goss/ EarthSky.

Finder charts for November Northern Hemisphere evenings

White dots for the moon over 2 days and Mercury in November along a green ecliptic line.
The slender waxing crescent moon will hang low in the southwest shortly after sunset on the evenings of November 14 and 15, 2023. Binoculars will help spot Mercury near the moon in the bright twilight on November 14, 2023. Chart via John Jardine Goss/ EarthSky.
White dot for Mercury and the Teapot asterism in November along a green ecliptic line.
For viewers in the Northern Hemisphere, Mercury will lie just above the horizon in the bright twilight shortly after sunset in the second half of November 2023. The Teapot asterism of Sagittarius is nearby but it will be difficult to spot in the bright evening twilight. Chart via John Jardine Goss/ EarthSky.

Finder charts for November Southern Hemisphere evenings

White dot for Mercury and a red dot for Antares in November along a green ecliptic line.
As viewed from the Southern Hemisphere, Mercury will appear low in the west shortly after sunset after November 10, 2023. Look for the bright red star Antares nearby. Chart via John Jardine Goss/ EarthSky.
White dots for the moon and Mercury, plus a red dot for Antares along a green ecliptic line.
As viewed from the Southern Hemisphere, the waxing crescent moon will form an attractive triangle with Mercury and Antares shortly after sunset on November 14, 2023. Chart via John Jardine Goss/ EarthSky.
White dots for Mercury and the moon with a red dot for Antares in November along a green ecliptic line from the Southern Hemisphere.
As viewed from the Southern Hemisphere, Mercury will pass the star Antares on November 16, 2023. Chart via John Jardine Goss/ EarthSky.
White dot for Mercury and the Teapot asterism in November along a green ecliptic line.
During the second half of November 2023, Mercury will lie low in the west below the Teapot asterism of Sagittarius shortly after sunset. Chart via John Jardine Goss/ EarthSky.

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 2023 and 2024

Note: Times are in UTC

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)

Jan 12, 2024: Greatest elongation (morning)
Feb 28, 2024: Superior conjunction (passes behind sun from Earth)
Mar 24, 2024: Greatest elongation (evening)
Apr 11, 2024: Inferior conjunction (races between Earth and sun)
May 9, 2024: Greatest elongation (morning)
Jun 14, 2024: Superior conjunction (passes behind sun from Earth)
Jul 22, 2024: Greatest elongation (evening)
Aug 19, 2024: Inferior conjunction (races between Earth and sun)
Sep 5, 2024: Greatest elongation (morning)
Sep 30, 2024: Superior conjunction (passes behind sun from Earth)
Nov 16, 2024: Greatest elongation (evening)
Dec 5, 2024: Inferior conjunction (races between Earth and sun)
Dec 25, 2024: Greatest elongation (morning)

Heliocentric view of Mercury December 2023

Circle with sun at center, planets around, and zodiac names on outer edge.
View larger. | Heliocentric view of solar system, December 2023. Chart via Guy Ottewell.

A comparison of elongations

The farthest from the sun that Mercury can ever appear on the sky’s dome is about 28 degrees. And the least distance is around 18 degrees.

Also, elongations are better or worse depending on the time of year they occur. So in 2023, the Southern Hemisphere had the best evening elongation of Mercury in August 2023. And the Northern Hemisphere had the best evening apparition in April.

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. That’s when Mercury appears higher above the horizon and farther from the glow of the sun. However, evening elongations in autumn are harder to see.

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 row of alternating light blue and gray arcs, each with a date and height in degrees.
View larger. | Mercury elongations compared. Here, gray areas represent evening apparitions (eastward elongation). And 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 2023 Astronomical Calendar. Used with permission.

More Mercury elongation comparisons for 2023

Annotated sky chart with arced rows of dots and dashed line for celestial equator.
View larger. | Mercury’s greatest evening elongations in 2023 from the Northern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell. Used with permission.
Sky chart with constellations, planet paths, and objects labeled.
View larger. | Mercury’s greatest evening elongations in 2023 from the Southern Hemisphere as viewed through a powerful telescope. The planet images are at the 1st, 11th, and 21st of each month. Dots show the actual positions of the planet for every day. Chart via Guy Ottewell. Used with permission.

Mercury photos from our community

Sunset with tall narrow trees and label of Mercury on small dot in blue twilight sky.
View at EarthSky Community Photos. | Joel Weatherly in Edmonton, Alberta, Canada, took this image on April 23, 2022. Joel wrote: “Lonely little Mercury is making an appearance in our evening skies. Despite being elusive, it was easy to see without optical aid once sighted.” Thank you, Joel!
Silhouette of 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!
Crescent moon, 2 labeled dots (Mercury and Venus) 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!

Bottom line: Mercury is visible in the evening sky. Look in the west as the sky is darkening. The planet will reach its greatest elongation overnight on December 4, 2023.

Submit your photos to EarthSky here.

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

The post Mercury at greatest evening elongation, start watching now first appeared on EarthSky.



from EarthSky https://ift.tt/Ik0Dqjg
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