THE 2022-2023 APPARITION OF MARS
By: Jeffrey D. Beish
(29-JAN-2022)
INTRODUCTION
Mars appears more Earth-like to us than most of the other planets because we can observe its surface, atmospheric clouds and hazes, and its brilliant white polar caps. The latter are composed of frozen CO2 and underlying water ice, and wax and wane during the Martian year. These aspects, along with the changing seasons and the possibility of life, have made Mars one of the most studied planets in our solar system.
The Red Planet Mars offers both casual and serious observers many challenges and delights, as well as providing astronomers a laboratory to study another planet’s atmosphere and surface. Some Martian features even appear to shift position around the surface over extended periods of time.There are several cooperating international Mars observing programs under way to assist both professional and amateur astronomers. These include the International Mars Patrol (I.M.P.) coordinated by the Mars Section of the Association of Lunar and Planetary Observers (A.L.P.O) and the Terrestrial Planets Section of the British Astronomical Association (B.A.A.). Information for observing Mars during a typical apparition is presented in a separate report titled, General Information for Apparitions of Mars. Also, you can find gobs of information at this site.
With the advent of modern CCD camera technology the amateur can produce useful images of Mars when it is as small as 3.5 arcsec . Early in an apparition, Mars rises in the east or morning sky and sets with the rotation of the Earth in the western or evening sky. During the past few apparitions (2001-2018), observers began to take CCD images when Mars was only 30 degrees away from the Sun. Since Mars was only a visual magnitude of ~1.8 then the planet would have been difficult to locate bright twilight hours.
In the pre-apparition reports the observer will find the motion of Mars in our sky, the characteristics for that particular apparition, information pertaining to the polar cap(s) and any special events that may be seen during that particular apparition. As usual a calendar of events will be included with each report that contains cardinal dates for seasonal activity and orbital information of Mars.
MOTION OF MARS IN OUR SKY
As a general rule, an "apparition" begins when a planet emerges from the glare of the Sun shortly after conjunction. Mars will be in conjunction with the Sun on October 08, 2021 (109.7° Ls); however, it will not be safe to observe Mars until after November 14, 2021 when it is at least 12 degrees away from the glare of the Sun.
The apparent declination of Mars begins at -22.5° in early January 2022 the constellation Ophiuchus and will descend south into the constellation Sagittarius, on January 20th, into Capriconus on March 6th, then into Aquarius on April 12th, and Pisces on May 20th until July 10, 2022. After that Mars will be positioned within Aries until August 10th when it moves into Taurus . Mars will be south of the celestial equator throughout the apparition until May 30, 2022 and begin climbing north of the celestial equator the next day. This is good news for those observing in the Northern Hemispheres because Mars will be seen high in their sky. Mars will be above the celestial equator until August 31, 2023.
By May 11, 2022, an ‘0.8’ visual magnitude Mars will be seen rising early in the morning sky in the constellation Aquarius and by August 27, 2022 will be at western quadrature with the phase defect or terminator of 45.7°. NOTE: The Solar Elongation for Mars is the angle between the lines of sight from Earth to the Sun and from Earth to Mars. When these lines of sight form a right triangle then Mars is at quadrature (eastern or western). For detailed definitions and graphics for the motion of Mars in our sky see these excellent web sites: Planetary Aspects and Elongations and Configurations.
Figure 1. A heliographic chart of the orbits of Mars and the Earth showing the relative positions of both planets. Quadrature is when Mars is directly east or west of Earth as shown.
The 2022-2023 apparition
of Mars begins retrogression, or retrograde motion against
the background stars eleven months after conjunction on October 30, 2022
(330° Ls) and continues through January 12, 2023
(8.2° Ls). Each night for this brief period of
time; before, during and after opposition the Red Planet will
appear to move backwards toward the western sky in the
Taurus
.
Since the Martian year is about 687 Earth
days long -- nearly twice as long as ours, the Martian
seasons are similarly extended. While the Earth’s seasons
are nearly equal in duration, the Martian seasons can vary by
as much as 52 days from each other due to that planet’s
greater orbital eccentricity (see Figure 2).
Figure 2. A heliographic chart of the orbits of Mars and the Earth showing the relative seasons of both planets in the planetocentric longitude system Ls. Graphic Ephemeris for the 2020 Perihelic Apparition of Mars. Original graph prepared by C.F. Capen and modified by J.D. Beish.
2022 APPARITION CHARACTERISTICS
Another general rule for predicting oppositions of Mars is from the following: the planet has an approximate 15.8-year periodic opposition cycle, which consists of three or four Aphelic oppositions and three consecutive Perihelic oppositions. Perihelic oppositions are also called "favorable" because the Earth and Mars come closest to each other on those occasions. We sometimes refer to this as the seven Martian synodic periods. This cycle is repeated every 79 years (± 4 to 5 days) and, if one were to live long enough, one would see this cycle nearly replicated in approximately 284 years. The 2022 Mars apparition is considered Transitional (between Aphelic and Perihelic) because the orbital longitude at opposition will be 79.3° from the aphelion longitude of 70° Ls and 100.7° Ls from perihelion (250° Ls).
NOTE: Ls is the planetocentric longitude of the Sun along the ecliptic of Mars’ sky. 0° Ls is defined as that point where the Sun crosses the Martian celestial equator from south to north, that is the planet’s northern hemisphere vernal equinox. The other Ls values that define the beginnings of Martian northern hemisphere seasons are: summer, 90° Ls; autumn, 180° Ls; and winter, 270° Ls. For Mars’ southern hemisphere these values represent the opposite seasons. Distance (A.U.) - Distance from Earth to Mars in astronomical units, where one (1) A.U. equals 92,955,807.267 miles or 149,597,870.691 km.
Closest approach occurs at 0218 UT on December 01, 2022
(347.1° Ls) with an apparent planetary disk diameter of
17.2’’ at a distance of 0.54446547536492 astronomical
units (AU) or 50,611,228 mi (81,450,876-km).
During closest
approach in 2022 the apparent diameter of Mars will be
5.4 arcsec smaller than it was at the same period in 2020;
however, it will be 19 degrees higher in the sky – good for observing the Red Planet for observers
in the northern and southern hemispheres of Earth. It
should also be noted that closest approach between Earth and
Mars is not necessarily coincident with the time of
opposition but varies by as much as two
weeks.
Opposition occurs 14 months after conjunction when Mars is on the opposite side of
the Earth from the Sun. At that time, the two planets will
lie nearly in a straight line with respect to the Sun,
or five weeks after retrogression begins.
Opposition will occur at 0536 UT on
December 08, 2022 (350.8° Ls) with an apparent planetary
disk diameter of 17.1 arcsec. Mars will remain visible
for 10 months after opposition and then become lost in the glare of the
Sun around October 10, 2023; as it approaches
the next conjunction (November 18,
2023). The cycle is complete in 780 Earth
days.
Figure 3. A simulated view of the appearance of Mars during opposition at 0536 UT on December 08, 2022 (350.8° Ls , CM 248.9°)
The
observable disk diameter of Mars will be greater than 6
arcsec from May 11, 2022 [-5.6° δ] (225.0°
Ls) and will not fall below this value until April 11, 2023
(49.3° Ls), lasting 11 months or 184 degrees
Ls. Imaging by CCD devices may begin with a disk
diameter of 5 arcsec or more, commencing on or about March
18, 2022.
The Sub-Earth (De) and
Sub-Solar (Ds) points are graphically
represented in Figures 4 and 5. The 2022-2023
Ephemeris of Mars is tabulated on Internet in this web
site. A glossary of Terms appears at the end of this
table.
Figure 4. As it approaches Earth, it will swell from a small apparent disk of 6" in May 11, 2022 to a maximum diameter of 17.2” at closest approach on December 01, 2022, and then shrink as it moves away. Images shown at 0h UT.
Figure 5. Graphic Ephemeris of Mars during the2022-2023 apparition from May 11, 2022 through April 11, 2023. Opposition (350.7° Ls) and 6 arcsec apparent diameter range are indicated. Plot illustrates the Declination (solid line), the latitude of the Sub-Earth point (De) or the apparent tilt (dashed line) in areocentric degrees, and the latitude of the Sub-Solar point (dotted line) in areocentric degrees. The areocentric longitude (Ls) of the Sun, shown along the bottom edge of the graph defines the Martian seasonal date. The value of Ls is 0° at the vernal equinox of the northern hemisphere, 70° when Mars is at aphelion, and 90° at the summer solstice of the northern hemisphere 251° when Mars is at perihelion, and 180° is northern autumn.
Figure 6. Graphic Ephemeris of Mars from May 11, 2022 through April 11, 2023. Opposition (350.7° Ls) and 6 arcsec apparent diameter range are indicated. Plot illustrates the apparent diameter of Mars in seconds of arc. The areocentric longitude (Ls) of the Sun, shown along the bottom edge of the graph defines the Martian seasonal date.
THE NORTH
AND SOUTH POLAR REGIONS
Astronomers will have a view of both polar regions during the next apparition. From the second week in May 2022 the Martian South Polar Region (SPR) will be positioned to be seen from the Earth and will remain so until February 08, 2023. Also, during the last week of August 2022 the North Polar Region (NPR) positioned to be seen from the Earth. For more detailed information on both polar regions click the north polar cap and south polar cap.
DUST STORMS
Observers should be aware that massive, planet-encircling storms usually occur in the southern hemisphere summer and in sensitive areas for the development of dust storms are in the south of Acidalium Mare, Chryse, Erythraeum Mare, Ophir and northeast Solis Lacus. While these events are nearly impossible to predict our studies show that the Martian dusty season should be ongoing from the beginning of the apparition through the end with the highest probability around in mid-May (225° Ls) and again peaking on or about October 04, 2022 (315° Ls) often starting in northwest Hellas.
Do not be surprised if another early dust storm occurs on or about January 27, 2022 (184° Ls). When a great dust storm
reaches maturity, Mars’ disk appears bright orange and
Mars’ surface features are obscured. For more detailed information on
Martian dust storms
on this web site.
SPECIAL EVENTS
During the 2001 Apparition of Mars a group of amateur and professional astronomers gathered in a driveway on Cudjoe Key, about 20 miles northeast of Key West, Florida to witness an interesting phenomenon of flashes or flares within a large, flat crater Schiaparelli, classically called "Edom Promontorium," that was first reported by Japanese astronomer Saheki on July 01,1954 at1315UT. This phenomenon again was reported by McClelland in 1954 and Tasaka in 1958. The impetuous for the June 05 - 10, 2001 "planet observing party" came from two articles, "The Martian-Flares Mystery," Sky and Telescope, Vol. 101, No. 5, May, pp115-123, by Thomas A. Dobbins and William Sheehan, and "Solving the Martian Flares Mystery," Dobbins and Sheehan, ALPO Web Site. Dobbins had organized this event to record and to photograph Mars hoping the Edom flare would occur.In a subsequent article Dobbins wrote in Sky & Telescope on March 4, 2004, that the observations supported the idea that, "The flares came from sunlight glinting off patches of frost or ice on the Martian surface." He states that "because the flashes occurred before Edom crossed the center of the planet's disk, the reflectors must have been tilted as much as 19° east-west; perhaps they rested on inclined surfaces on the ground, for example, the slopes of dunes. Intriguingly, the light-colored oval of Edom Promontorium corresponds to the large, flat crater Schiaparelli, and in May 2002 NASA's Mars Odyssey spacecraft found indications that this region is anomalously rich in water ice for a site near the Martian equator."
For those interested in catching a glimpse of possible "flares" from the surface of Mars there will be a period when it will be possible to see it as the De and Ds are coincident that will be on or about December 05, 2022. It is expected that Mars will be situated favorably in the sky for observers to record this rare event when the De and Ds will be very close together. When planning for the upcoming December 2022 event and based on the previous observations, the earliest one may expect to see the Edom flare would be around two hours before the time when Edom Promontorium would appear on the central meridian, see Table-1 below for dates when De - Ds +/- 1.0°:
Table 1. EDOM PROMONTORIUM FLARES
Figure 7. Graphic illustration of Mars showing when the possible reoccurrence of Edom flare from 2022-12-03 0804UT to 2022-12-07 1028UT
MOON OCCULTS MARS - DECEMBER 08, 2022
A rare event will occur during the 2022 Opposition of Mars as the Moon occults Mars from 0454UT until 0556UT for observers in most of north America (see IOTA map of visual areas of Moon/Mars occulation). The table below describes UT dates/times of the Ingress, Center and Egress of Mars behind the disk of the Moon.TABLE 2. MOON OCCULTS MARS - DECEMBER 08, 2022
Table 3. CALENDAR OF EVENTS -- MARS, 2022-2023
|
DATE |
PHYSICAL |
REMARKS |
|
2021 Oct 08 |
Ls 109.7° |
Conjunction. Mars is behind the Sun ~2.629 AU. |
|
2022 Feb 24 |
Ls
180° |
Equinox
- Northern Autumn/Southern Spring. South Polar Cap (SPC) maximum width. Is the North Polar
Hood present. Does SPH or frost cover |
|
2022 May 11 |
Ls
225.0° |
Apparition begins for observers using 4-inch to 8-inch apertures telescopes and up. Begin low-resolution CCD imaging. Views of surface details not well defined. Bright SPC projection Novissima Thyle (300°W - 330°W) areographic longitude. Dark rift Rima Augusta connected from 60° to 270° longitude. Rima Australis visible in SPC (290°-350°W)? W-clouds possible. SPC bright projection Argenteus Mons (10° W - 20° W). SPC Dust clouds in in the south of Acidalium Mare, Chryse, Erythraeum Mare, Ophir and northeast Solis Lacus? SPC ~38° ±8° |
|
2022 Jun 19 |
Ls
250° |
Mars at Perihelion. SPC in rapid retreat. Novus Mons smaller. Dust clouds expected over Serpentis-Hellaspontus (Ls 250° - 270). Syrtis Major beginning to narrow. Frost in bright deserts? Orographic clouds (W-clouds) possible. Elysium and Arisa Mons bright? Note: Several "planet-encircling dust storms have been reported during this season. High probability for dust clouds at 255° Ls. SPC ~ 24° ±4° |
|
2022 Jul 21 |
Ls
270° |
Solstice - Northern Winter/Southern Summer. W-clouds present? NPH extends 50° N? Decreased number of White clouds. "Syrtis Blue Cloud"? White areas in deserts? Dust clouds in south until 270° Ls? Watch for planetary system clouds bands. Orographic cloud over Arsia Mons? Syrtis Major is narrow. SPC ~17° ±2° |
|
2022 Jul 24 |
Ls
271.8° |
W-clouds present? NPH extends 50° N? Decreased number of White clouds. "Syrtis Blue Cloud"? White areas in deserts? Dust clouds in south until 270° Ls? Watch for planetary system clouds bands. Orographic cloud over Arsia Mons? Syrtis Major is narrow. SPC ~17° ±2° |
|
2022 Aug 27 |
Ls
292.8° |
Mars at quadrature. Look for orographic clouds over the Tharsis volcanoes. Orographic cloud over Arsia Mons? W-Cloud? SPC small (SPC ~ 10° ±2°). |
|
2022 Sep 05 |
Ls
298.3° |
White areas? Orographic clouds over the Tharsis volcanoes. W-Cloud? Orographic cloud over Arsia Mons? SPC very small, difficult to see. SPC ~11° ±1° |
|
2022 Oct 02 |
Ls
314.2° |
|
|
2022 Oct 30 |
Ls 330° |
Retrogression
Begins. |
|
2022 Dec 01 |
Ls
347.1° |
Mars
at Closest Approach. NPC large hood present. W-Cloud? Orographic cloud over Arsia Mons? Topographic cloud over |
|
2022 Dec 08 |
Ls
350.7° |
Mars
at Opposition.
NPC large hood
present. W-Cloud? Orographic cloud over Arsia Mons?
Topographic cloud over |
|
2022 Dec 26 |
Ls
359.8° |
Equinox - Northern Spring/Southern Autumn. North Polar Hood (NPH) breaking up, North Polar Cap (NPC) should be exposed. ("Areo-" is a prefix often employed when referring to Mars or "Ares.") |
|
2023 Jan 12 |
Ls 8.2° |
Retrogression
Ends. North
Polar Hood (NPH) breaking up and North Polar Cap (NPC) should be exposed. |
|
2023 Jan 21 |
Ls
12.6° |
North
Polar Hood (NPH) breaking up and North Polar Cap (NPC) should be exposed. |
|
2023 Feb 08 |
Ls
21.1° |
NPC nearly static or entering erratic retreat, hood dissipating? Orographic cloud over Apollinaris Petera? NPC~60° - 65° |
|
2023 Mar 03 |
Ls 31.7
° |
Limb clouds and hazes should start to increase. Dust clouds in NPR? NPC~60° - 65° |
|
2023 Apr 11 |
Ls
49.3° |
Continue
NPC measurements. Is North Cap fairly static or entering rapid retreat phase.
|
|
2023 May 28 |
Ls
70° |
Mars
at Aphelion. Is
North Cap fairly static or entering rapid retreat phase. Watch for
"Aphelic Chill" in NPR (usually between 60° and 70° Ls). Antarctic
hazes, hood. |
|
2023 Nov 18 |
Ls 150.2° |
Conjunction. Mars is behind the Sun ~2.526AU. |