Seasons on Mars

Most recent answer: 10/22/2007

Q:
I was wondering if light intensity changed on Mars during season change. If so, how and why?? Also, do you have any diagrams or pictures or links to the images relating to light intensity or seasons? THankyou! ur help is greatly appreciated!
- Claudia
St. Aidan’s AGS, Brisbane, Queensland, Australia
A:
Seasons on Earth are caused not by the change in distance from the sun (the orbit is very close to cirular) but by the tilt of the Earth’s axis. Remember that when it’s winter here in the northern hemisphere, it’s summer in the southern hemisphere. So it’s a question of which parts of the Earth are more directly facing the Sun at which parts of the year.
The Earth’s axis is tilted 23.45 degrees from vertical. Mars is very similar to earth in that it is tilted by 25.19 degrees. So the seasons on Mars will be very similar to those on Earth. The difference is that they are going to be about twice as long since Mars take about 2 years (687 days) to make one trip around the sun. So (just like on Earth) the part of Mars experiencing winter gets less sunlight per area than the part experiencing summer.
This is a good website that helps explain the seasons:
http://astrosun.tn.cornell.edu/courses/astro201/seasons.htm

-James (and mike)

(published on 10/22/2007)