Picture of Mars

Mars

(Photo courtesy of NASA/JPL)

General Information

Diameter (equatorial)	6794 km
Mass	6.4185x10^20 kg
Atmospheric pressure	4.0 to 8.7 mb
Atmospheric composition	95.32% CO₂, 2.7% N₂, 1.6% Ar, 0.13% O₂, 0.08% CO
Diurnal temerature range	-89 to -31 Centigrade
Rotation Period	24 hours 37 min. 37.4 sec.
Orbital Period (siderial)	686.98 days
Minimum distance from the Sun	206.62 million km
Maximum distance from the Sun	249.23 million km

Mars Animation

I created this animation from a series of 240 images taken over the course of a couple of weeks at the end of August through the beginning of September 2003. You can see the bright, white south polar ice cap at the bottom of the planet and various dark features on the planet's surface. The slightly bluish tinted edges along the top and left sides are likely to be early morning clouds that evapourate as the planet turns into full sunshine. Note that they are more persistant along the top since this is at a high northern latitude, where it is generally much colder.

There are 24 frames, with 22 of them repeated to make the animation "rock" back and forth. Each frame was created from 10 raw images taken 1 minute apart. Each group of 10 images was seperated in time by 30 minutes (except the last two in the sequence). So each frame is a picture of what Mars looked like at the following times Pacific Standard Time (UTC-7 hours):

21:30 10 September PST (04:30 11 September UTC)
22:00 10 September PST (05:00 11 September UTC)
22:30 10 September PST (05:30 11 September UTC)
23:00 10 September PST (06:00 11 September UTC)
23:30 10 September PST (06:30 11 September UTC)
00:00 11 September PST (07:00 11 September UTC)
22:00 06 September PST (05:00 07 September UTC)
22:30 06 September PST (05:30 07 September UTC)
23:00 06 September PST (06:00 07 September UTC)
23:30 06 September PST (06:30 07 September UTC)
00:00 07 September PST (07:00 07 September UTC)
00:30 07 September PST (07:30 07 September UTC)
21:53 01 September PST (04:53 02 September UTC)
22:23 01 September PST (05:23 02 September UTC)
22:53 01 September PST (05:53 02 September UTC)
23:23 01 September PST (06:23 02 September UTC)
23:53 01 September PST (06:53 02 September UTC)
22:30 29 August PST (05:30 30 August UTC)
23:00 29 August PST (06:00 30 August UTC)
23:30 29 August PST (06:30 30 August UTC)
00:00 30 August PST (07:00 30 August UTC)
00:30 30 August PST (07:30 30 August UTC)
23:15 26 August PST (06:15 27 August UTC)
00:05 27 August PST (07:05 27 August UTC)

Note that the first frames in the sequence come from the latest observing session and last frames in the sequence come from the earliest observing session. This apparent paradox is caused by the fact that Mars's axial rotatin period (ie. it's "day") is only slightly longer than ours, here on Earth. This means that if you were to go out and look at Mars at exactly the same time every night, it would appear to slowly rotate backwards relative to it's normal rotation direction. Therefore, on any given night, a sequence of forward rotating frames can be captured, but these frames will be "behind" any frames taken during a night a few days later. In the animation, the "forward" rotation direction is from left to right. When these pictures were taken, Mars was visually about the size of a baseball / cricket ball over 1/3 mile (500m) away. In other words, not very big !

Each set of 10 images were processed using Registax. I then used Corel Animation Shop (formerly from JASC) to create the actual animation.

The telescope used was a Meade 10 inch f4 Schmidt-Newtonian LXD55 with a 20mm Super Plossl fitted in the focuser. The camera was a Sony MVC-CD1000 used at maximum zoom. This resulted in Mars being about 110 pixels accross on the camera sensor. This translates to about 0.23 arc-seconds per pixel. Since my telescope has a resolving power of 0.45 arc-seconds, the image was "over-sampled" by about a factor of 2x. Exposure times were 1/60^th second on shutter speed priority semi-automatic mode.