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Perihelic Opposition of Mars ( 29 August 2003 )


Date: 29-8-2003
Time: 22:00 (Hong Kong Time
Telescope: Refractor (125mm aperture, 1000mm focal length)
Projection eyepiece: 12mm
Camera: DV Camera
Exposure: 1/25sec (Stacking of 891 frames)



Sky at 8pm on 29 August

Planetary opposition happens when the Earth lies between the Sun and the planets in a straight line. There are only oppositions of superior planets. For Mars, it takes place every 780 days. Every 15 years, a perihelic opposition occurs and Mars will be closest to the Earth by then.

From the Earth, the surface features of this red planet can be easily seen. The perihelic opposition of Mars in 2003 is the closest in the last 60,000 years. By that time, the apparent diameter of Mars will be as large as 25.1 arc seconds. Shining at -2.9 magnitude, it will become the brightest star in the night sky for weeks. Mars will rise at 7:00 pm in the east and can be seen throughout the night.

You are advised to observe from a site with unobstructed view of southeast. To see the surface of Mars, you need an astronomical telescope. It appears as a bright orange-red spot when seen with naked eye.

If you missed this perihelic opposition of Mars, you have to wait until 2287 for an even closer one!

Future close approaches of Mars to Earth (until 3000AD, in ascending order of distance)

Date (Universal Time) Distance (km)
8/9/2729 55,651,000
3/9/2650 55,652,000
5/9/2934 55,676,000
28/8/2287 55,688,000
11/9/2808 55,696,000
30/8/2571 55,708,000
2/9/2366 55,709,000
27/8/2003 # 55,758,000

#  As the orbits of Mars and Earth are not perfect circle, the date of close approach and that of opposition may differ by several days.


Mars completes one rotation every 24 hours 30 minutes. 
Try observing various parts of Mars at different times of the night.

Weather is ever changing on Mars. 
Global dust storm may happen occasionally and cover the whole planet.

Rotating Mars Globe

Source of data & Photo credit: NASA