THE 2033-2034 PERIHELIC APPARITION OF MARS
By: Jeffrey D. Beish (21-DEC-2020)

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 (2025-2031), observers began to take CCD images when Mars was only 32 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 July 11, 2032 (24.1° Ls); however, it will not be safe to observe Mars until after August 19, 2032 when it is at least 12 degrees away from the glare of the Sun.

The apparent declination of Mars begins at -18.4° by the end of January 2033 the constellation Libra and will descend south into the constellation Scorpius by February 13, 2033. Then into Ophiuchus on February 20th then into Sagittarius by March 28th. Mars will be south of the celestial equator throughout the apparition. This is not good news for those observing in the Northern Hemispheres because Mars will be seen fairly low in their sky during the entire apparition. Good news for southern hemisphere observers however.

By March 04, 2033, a ‘0.6’ visual magnitude Mars is seen rising early in the morning sky in the constellation Ophiuchus, it will be at western quadrature  and the phase or terminator will be at 38.6°.  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 2033-2034 apparition of Mars begins retrogression, or retrograde motion against the background stars eleven months after conjunction on May 26, 2033 (172.5° Ls) and continues through August 01, 2033 (211.5° 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 Sagittarius. 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 2033 Aphelic Apparition of Mars. Original graph prepared by C.F. Capen and modified by J.D. Beish.


2033 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 2033 Mars apparition is considered Perihelic because the orbital longitude at opposition will be 59.3° from the longitude of 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.
Opposition occurs nearly 13 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 at 0124 UT on June 27, 2033 (190.7° Ls) with an apparent planetary disk diameter of 21.8 arcsec. Mars will remain visible for more than 12 months after opposition and then become lost in the glare of the Sun around July 13, 2034 as it approaches the next conjunction (August 19, 2034). The cycle is complete in 780 Earth days.

Closest approach occurs at 1119 UT on July 05, 2033 (195.3° Ls) with an apparent planetary disk diameter of 22.1'' at a distance of 0.4230186 astronomical units (AU) or 39,322,034 mi (63,282,679-km).  During closest approach in 2033 the apparent diameter of Mars will be 5.2 arcsec larger than it was at the same period in 2031 and it will be 13.2 degrees lower in the sky – not quite as good for observing the Red Planet for observers in the northern hemisphere.  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.

Figure 3. A simulated view of the appearance of Mars during opposition at 0124 UT on June 27, 2033 (190.7° Ls, CM 165.8°)

The observable disk diameter of Mars will be greater than 6 arcsec from January 31, 2033 [-18.4° δ ] (114.8° Ls) and will not fall below this value until January 21, 2034 (318.2° Ls), lasting nearly 13 months or 203 degrees Ls. Imaging by CCD devices may begin with a disk diameter of 5.1 arcsec or more, commencing on or about January 01, 2033.

The Sub-Earth (De) and Sub-Solar (Ds) points are graphically represented in Figures 4 and 5. The 2033-2034 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 January 31, 2033 to a maximum diameter of 22.1" at closest approach on July 05, 2033, and then shrink as it moves away. Images shown at 0h UT.


Graphic Ephemeris of Mars during the 2033-2034 apparition from January 31, 2033 through January 21, 2034. Opposition (190.7° Ls) and 6 arcsec apparent diameter range arc 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 January 31, 2033 through January 21, 2034. Opposition (190.7° Ls) and 6 arcsec apparent diameter range arc 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 this apparition. From the first week in January through mid-March 2033 the Martian North Polar Region (NPR) will be positioned to be seen form the Earth. The South Polar Region (SPR) will be visible from January 01, 2033 and remain throughout the entire apparition. For more detailed information on both polar regions click the north polar cap click to this web site. Information on the south polar cap click to this web site.

DUST STORMS

Observers should be aware that during the next apparition of Mars in 2033 a major dust storm may occur to block our view of the clouds and surface of the Red Planet. While it is nearly impossible to predict these events our studies show that the Martian dusty season should begin on or about May 12, 2033 (165° Ls) through April 09, 2034 (359° Ls) with the highest probability around mid-October (255° Ls) and again peaking January 15, 2023 (315° Ls). Massive, planet-encircling storms usually occur in the southern hemisphere summer and usually in sensitive areas for the development of dust storms are in northwest Hellas.

Do not be surprised if another early dust storm occurs on or about June 16, 2033 (184° Ls). Observers should be alert for dust clouds in the northeast Hellas Basin, the Serpentis-Noachis region, and the Solis Lacus region For more detailed information on Martian dust storms on this web site.


SPECIAL EVENTS

For those interested in catching a glimpse of possible "flares" from the surface of Mars (Edom) there will be a period when it will be possible to be seen when the De and Ds are coincident will be on or about June 21, 2033 (see Figure 7). The last time this event was recorded was during June 07, 2001 when the De = 1.6° and Ds = 2.7° and Mars was situated favorably in the sky for observers to record this rare event. The De and Ds will be very close together in this apparition; however, they will be slightly lower (-3.1° and -3.1° respectively) than in 2001 when the "flares" were seen Detailed report of the 2001 event (Dobbins, Thomas A. and Sheehan, William (2001), "The Martian-Flares Mystery," Sky and Telescope, Vol. 101, No. 5, May, pp115-123) and "Solving the Martian Flares Mystery," Dobbins and Sheehan, ALPO Web Site.  See table below for dates when De - Ds +/- 1.0°:

First Period: Di = 21.1" to 21.5"

            NOTE: Di = apparent diameter of Mars
                            De = Declination of Earth from Mars
                          Ds = Declination of Sun from Mars
       De - Ds = coincident
                      i = phase defect in degrees


Figure 7. Graphic illustration of Mars showing possible reoccurrence of Edom flare on 2033-06-21.



CALENDAR OF EVENTS -- MARS, 2033 - 2034

DATE

PHYSICAL

REMARKS

2032 Jul 11

Ls 24.1°

Conjunction. Mars is behind the Sun ~2.629 AU.

2033 Jan 31 

Ls 114.8° 
De 10.9° 
Ds  22.7° 
RA 15:36

Dec -18.4° 
A.Dia  6’’

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.  NPC still retreating? Are limb arcs increasing in frequency, intensity? Antarctic hazes, hood? Cloud activity high? Tempe-Arcadia-Tharsis-Amazonis regions bright in a pattern appearing as the "domino effect." Discrete clouds?

2033 Mar 04

Ls 129.9° 
De 3.6° 
Ds 19.1° 
RA 16:50 
Dec -21.9° 
A. Dia 7.5’’

Mars at quadrature. White clouds and ice-fogs frequent. Syrtis Major and Mare Acidalium broad and dark? °). Orographic cloud over Olympus Mons.  NPC ~13 ±1

2033 Mar 11 

Ls 133.3° 
De  3.6° 
Ds  18.1° 
RA 17:06 
Dec -22.4° 
A.Dia   8’’

White clouds and ice-fogs frequent. Syrtis Major and Mare Acidalium broad and dark? °). Orographic cloud over Olympus Mons.

2033 Apr 05 

Ls  145.6° 
De  -2.7° 
Ds  13.9° 
RA  17:57 
Dec -23.5° 
A. Dia  10’’

If both polar caps are visible look for haze canopy? Clouds and frosts prominent in north. Clouds area in south. Syrtis Major broad.

2033 Apr 23 

Ls 154.9° 
De  -5.2° 
Ds  10.4° 
RA 18:27 
Dec -23.9° 
A.Dia   12’’

Mid-summer. Northern clouds frequent. Syrtis Major broad. Are both polar hoods visible?

2033 May 26

Ls 172.5° 
De  -6.4° 
Ds  3.2° 
RA 18:55 
Dec -25.2° 
A.Dia 17.2’’

Retrogression Begins. Late southern winter, SPH present and edge of NPH visible. Hellas frost covered? Are W-clouds present?

2033 Jun 08

Ls 180° 
De  -5.2° 
Ds  0.1° 
RA 18:51 
Dec -26.2° 
A.Dia 19.5’’

Equinox - Northern Autumn/Southern Spring. South Polar Cap (SPC) maximum width.   Is the North Polar Hood present? Does SPH or frost cover Hellas? Hellas should begin to clear and darken. Are W-clouds present? South cap emerges from darkness of Winter. SPH thinning and forms "Life Saver Effect"? 

2033 Jun 27

Ls 190.7° 
De -2.1° 
Ds -4.5° 
RA  18:31 
Dec -27.8° 
A.Dia 21.8’’

Mars at Opposition.  SPC should be free of its hood, large and bright. Possible W-clouds in Tharsis-Amazonis. Syrtis Major shrinks or fading on eastern border. NPH bright. White areas brighter? White areas brighter? Within Hellas the features Zea Locus and Alpheus darkening? Mare Hadriacum (265°W, 40°S) and Yaonis Regio (318°W, 43°S) connected the canal Peneus?

2033 Jul 05 

Ls 195.3° 
De -0.7° 
Ds -6.5° 
RA  18:20 
Dec -28.2° 
A.Dia 22.1’’

Mars at Closest Approach. SPC should be free of its hood, large and bright. Possible W-clouds in Tharsis-Amazonis. Syrtis Major shrinks or fading on eastern border. NPH bright. White areas brighter? White areas brighter? Within Hellas the features Zea Locus and Alpheus darkening? Mare Hadriacum (265°W, 40°S) and Yaonis Regio (318°W, 43°S) connected the canal Peneus?

2033 Aug 01 

Ls 211.5° 
De  1.7° 
Ds  -12.9° 
RA 17:59 
Dec -25.6° 
A.Dia 19.9’’

Retrogression Ends. SPC develops dark Magna Depressio at (270°W, 80°S). Syrtis Major narrows rapidly. W-clouds? At 215°Ls Rima Australis (a dark rift) appears connected with Magna Depressio from 20° to 240° longitude; and SPC develops bright projection at 10° - 20° longitude in Argenteus Mons (10°-20°W). Dust cloud in Serpentis-Hellaspontus or Noachis-Hellas? Syrtis Major very narrow? 

2033 Oct 01 

Ls 250° 
De -8.7° 
Ds -23.5° 
RA  19:28
Dec  25.1° 
A.Dia 12.2’’

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. 

2033 Oct 03 

Ls  250.9° 
De  -9.2° 
Ds  -23.7° 
RA  19:33
Dec -24.9° 
A.Dia 12’’

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. 

2033 Oct 27 

Ls  266.2° 
De -15.5° 
Ds -25.1° 
RA  20:35
Dec -21.1° 
A.Dia 10’’

Novus Mons reduced to a few bright patches and soon disappears. Windy season on Mars begins, dust clouds present? Watch for initial dust clouds in south. White patches in bright areas? Hellas bright spots? Numerous bright patches. Syrtis Major beginning to narrow.

2033 Nov 02

Ls  270° 
De -17.0° 
Ds  -25.2° 
RA 20:51
Dec -19.9° 
A.Dia 9.6’’

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.

2033 Nov 30

Ls  287.4° 
De -22.9° 
Ds  -24.0° 
RA  22:06
Dec -13.1° 
A.Dia 8’’

Look for orographic clouds over the Tharsis volcanoes. Orographic cloud over Arsia Mons? W-Cloud?  SPC small.

2034 Jan 21

Ls  318.2° 
De -25.8° 
Ds  -16.5° 
RA  00:22
Dec  2.2° 
A.Dia  6’’’

Wave or frontal cloud activity from NPR? Bright spots in Hellas? Orographic cloud over Arsia Mons? Topographic cloud over Libya? Topographic cloud over Edom? High probability of dusty storm at 315° Ls.

2034 Aug 19

Ls 13.9°

Conjunction. Mars is behind the Sun ~2.675AU.