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By: Jeffrey D. Beish (02-19-2008)


Always an intriguing world, Mars offers both casual and serious observers many challenges and delights. It also provides astronomers a laboratory to study the atmosphere and surface of another planet, including the behavior of condensates and their effects on its atmosphere and surface. Mars is similar to Earth in that it has four seasons, exhibits global climates, changing weather patterns, annual thawing and growing of polar caps, storm clouds of water ice, howling dusty winds, and a variety of surface features that predictably change in color and size and appear to shift position over extended periods of time.

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), the International MarsWatch, the Terrestrial Planets Section of the British Astronomical Association (B.A.A.), and the Mars Section of the Oriental Astronomical Association (O.A.A.).

Information for observing Mars during a typical apparition is presented in a separate report titled, "General Information for Apparitions of Mars."

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 (2001-2012), 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 April 17, 2013 (303.0° Ls); however, it will not be safe to observe Mars until after the first week of June 2013 when it is at least 12 degrees away from the glare of the Sun.

The apparent declination of Mars begins at 21.3° in mid-June 2013 and climbs north of the celestial equator throughout June and mid-July in the constellation Taurus. This is good news for those observing in the Northern Hemispheres because Mars will be seen fairly high in their sky during the early stages of the apparition. Mars will continue to be a few degrees north of the celestial equator until December 13, 2013 when it goes south for the remainder of the apparition and crossing from the constellation Virgo into Libra during the mid-August.

By January 03, 2014, a '0.8' visual magnitude Mars is seen rising early in the morning sky in the constellation Virgo, it will be at western quadrature  and the phase or terminator will be at its widest (36°). 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.

In 2014 Mars begins retrogression, or retrograde motion against the background stars ten months after conjunction March 02, 2014 (97° Ls) and continues through May 21, 2014 (134° Ls).  Each night for this brief period before, during and after opposition the Red Planet will appear to move backwards toward the western sky in the Virgo.

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 2012 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 Aphelicoppositions 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 2014 Mars apparition is considered Aphelic because the orbital longitude at opposition will be only 44° from the aphelion longitude of 70° Ls (Ls will be defined later).

Opposition occurs nearly 12 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 and a half weeks after  retrogression begins. Opposition will occur at 2057 UT on April 08, 2014 (113.7° Ls) with an apparent planetary disk diameter of 15.1 arcsec. Mars will remain visible for more than twelve months after opposition and then become lost in the glare of the Sun around April 30, 2015 as it approaches the next conjunction (June 14, 2015). The cycle is complete in 780 Earth days.

Closest approach occurs at 1254 UT on April 14, 2014 (116.4° Ls) with an apparent planetary disk diameter of 15.2'' at a distance of 0.6175118 astronomical units (AU) or 57,401,194 miles (92,378,452 km).  During closest approach in 2014 the apparent diameter of Mars will be more than 1.3 arcsec larger than it was at the same period in 2012;  however, it will be nearly 15 degrees lower in the sky not quite as good for observing the Red Planet. [NOTE: one (1) A.U. equals 92,955,621 miles or 149,597,870 km]. 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 2057 UT on April 08, 2014 (113.7° Ls)

The observable disk diameter of Mars will be greater than 6 arcsec from December 12, 2013 [0.1°
d] (61.5° Ls) and will not fall below this value until October 06, 2014 (208.9° Ls), lasting 13 months or 208 degrees Ls.  Imaging by CCD devices may begin with a disk diameter of 4 arcsec or less, commencing on August 19, 2013.

The Sub-Earth (De), Sub-Solar (Ds) points and Declination are graphically represented in Figures 5 and 6. The 2013 and 2014 Ephemeris of Mars is tabulated the following URL: 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 December 12, 2013 to a maximum diameter on April 14, 2014, and then shrink as it moves away.  Closest approach occurs on April 14, 2014 (Opposition April 08, 2014).  From January 2014 through September 2014 are the prime observing months.

Figure 5. Graphic Ephemeris of Mars during the 2013-2014 apparition from December 12, 2013 through October 06, 2014.   Opposition and 6 arcsec apparent diameter range arc indicated.  Plot illustrates the Declination (black line),   the latitude of the Sub-Earth point (De) or the apparent tilt (brown line) in areocentric degrees, and the latitude of the Sub-Solar point (green 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 250° when Mars is at perihelion, and 180° is northern autumn.

Figure 6. Graphic Ephemeris of Mars from December 12, 2013 through October 06, 2014.  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 the next apparition. From the first week in July 2013 the Martian North Polar Region (NPR) began to tilt toward the Earth and will remain so until October 21, 2014 when it reaches 0° De. Also, the terminator may begin to cover the cusp of the polar cap because the Ds will then further south than the De, or more negative, along with the southward direction of the De. After that, the North Pole will be in the shadow of the southern portion of the limb terminator.

By the second week in September 2013 (20° Ls), the NPC should be free of its hood; however, Mars will be too small to begin micrometer measurements until mid-December. For more detailed information on the south polar cap go to and click: or the north polar cap click:


For those interested in catching a glimpse of possible "flashes" from the surface of Mars there will be two periods when possible "flashes" may be seen on Mars. When the De = Ds +/- 1.0° will be on or about December 22, 2013 through January 04, 2014 and between April 11 and April 21, 2014.

Table 2. CALENDAR OF EVENTS -- MARS, 2013-2014
2013 Apr 17 Ls 303° Conjunction. Mars is behind the Sun ~2.431 AU.
2013 Aug 01 Ls 0° 
De 0.0° 
Ds -0.1° 
RA 06:54 
Dec  23.61° 
A.Dia 3.9
Equinox - Northern Spring/Southern Autumn. North Polar Hood (NPH) begins to break up. North Polar Cap (NPC) should be exposed at approximately 65° Areographic latitude. ("Areo-" is a prefix often employed when referring to Mars or "Ares.")
2013 Dec 12 Ls 61.5° 
De  24.0° 
Ds 21.6° 
RA 12:10 
Dec 1.0° 
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. 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  Watch for "Aphelic Chill" in NPR (usually between 60° and 70° Ls) and possible halt in thawing of NPC. Views of surface details well defined. Rima Tenuis may appear (140° and 320° areographic meridians). Cloud activity in north increasing (NPC Width ~43° ±12°). 
2014 Jan 01 Ls 70° 
De 22.7° 
Ds 23.2° 
RA 12:46
Dec -2.6° 
A. Dia 6.9
Mars at Aphelion. Is NPC fairly static or entering rapid retreat phase. Watch for "Aphelic Chill" in NPR (usually between 60° and 70° Ls). NPC Rima Tenuis may appear.  Antarctic hazes, hood. South polar regions becoming difficult to observe. Any signs  NPC width ~36° ±13°
2014 Jan 20 Ls 78.1° 
De 21.1° 
Ds 24.3° 
RA 13:14
Dec -05.3° 
A. Dia  8
NPC in rapid retreat? Are limb arcs increasing in frequency, intensity. Antarctic hazes/hood. Cloud activity increases. "Aphelic Chill" in NPR should be ended. (NPC Width ~29° ±11°).


2014 Feb 15 Ls 90° 
De 19.1° 
Ds 24.0° 
RA 13:41
Dec -7.6° 
A.Dia 10.1
Solstice - Northern Summer/Southern Winter. Orographic clouds over the Tharsis volcanoes W-Cloud? Local seasonal clouds should wrap around Syrtis Major and be prominent in Lybia. Hellas white cloud and Ice-fog activity? Discrete clouds? NPC remnant? Lemuria (210° W, 82° N) detached from NPC? Any other detachments (projections at 135° W and 290° W) near NPC remnant, NPC Width ~21° ±7°.
2014 Mar 02 Ls 61.9°
De 22.6°
Ds 21.7°
RA 11:40
Dec 6.1°
A.Dia 11.1
Retrogression Begins. Mars begins retrogression, or retrograde motion against the background stars nearly 3xx days after conjunction, when it appears to move backwards toward the west for a brief period before, during and after opposition.    
(NPC Width ~44.5° ±1.0°).
2014 Apr 08 Ls 113.3° 
De 21.0° 
Ds 22.6° 
RA 13:15
Dec -05.3° 
A.Dia 15.8
Mars at Opposition.  NPC in rapid retreat? 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?  
NPC width ~18° ±5°
2014 Apr 14 Ls 116.1° 
De 21.6° 
Ds 22.1° 
RA 13:06
Dec -04.6° 
A.Dia 15.1
Mars at Closest Approach. Is Mare Acidalium broad and dark? Bright spots in Tempe-Arcadia-Tharsis-Amazoins? "Domino effect" appears around 120° - 125° Ls. Topographic clouds increase.   
NPC width ~17° ±4°
2014 May 21 Ls 133.6 ° 
De 24.5° 
Ds 17.7 ° 
RA 12:34
Dec -2.8° 
A.Dia 12.8
Retrogression Ends. Mars begins westward motion against the background stars. White clouds and ice-fogs frequent. Syrtis Major and Mare Acidalium broad and dark?  Orographic cloud over Olympus Mons.  NPC width ~14° ±0.5°


2014 Jun 23 Ls 150.1° 
De 24.5° 
Ds 12.1° 
RA 12:56
Dec -06.3° 
A.Dia 10
Mid-summer. Northern clouds frequent. Syrtis Major maximum width. Are both polar hoods visible?
2014 Jul 29 Ls 169.1° 
De 21.2° 
Ds 4.5° 
RA 12:56
Dec -06.3°
A.Dia 8
Late southern winter. Edge of NPH should be visible and the SPH should begin to clear. Hellas frost covered? Are W-clouds present?
2014 Aug 18 Ls 180° 
De 17.7° 
Ds  0° 
RA 14:40
Dec -16.9° 
A.Dia 7.3
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" ?   SPC width ~50° ±9°.
2014 Oct 06 Ls 208.9° 
De 4.8° 
Ds  -11.7° 
RA 16:55
Dec -24.1° 
A.Dia 6
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?  SPC width ~ 49° ±4°
2014 Dec 11 Ls 250° 
De -15.9° 
Ds  -23.2° 
RA 20:29
Dec -20.5° 
A.Dia 5
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 255° Ls. 
SPC width ~ 27° ±3°
2015 Jun 14 Ls 358° Conjunction. Mars is behind the Sun ~2.57AU.