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.

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.

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.

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.

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.

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.

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 Tsuneo Saheki on July 01,1954 at1315UT. This phenomenon again was reported by Clark McClelland in 1954 and Ichiro 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 June 21, 2033. 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 June 2033 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°: