Seasons
See also: Astronomy on Mars#SeasonsMars has an axial tilt of 25.2°. This means that there are seasons on Mars, just as on Earth. The eccentricity of Mars' orbit is 0.1, much greater than the Earth's present orbital eccentricity of about 0.02. The large eccentricity causes the insolation on Mars to vary as the planet orbits the Sun (the Martian year lasts 687 days, roughly 2 Earth years). As on Earth, Mars' obliquity dominates the seasons but, because of the large eccentricity, winters in the southern hemisphere are long and cold while those in the North are short and warm.
The seasons present unequal lengths are as follows:
| Season | Sols (on Mars) |
Days (on Earth) |
|---|---|---|
| Northern Spring, Southern Autumn: | 193.30 | 92.764 |
| Northern Summer, Southern Winter: | 178.64 | 93.647 |
| Northern Autumn, Southern Spring: | 142.70 | 89.836 |
| Northern Winter, Southern Summer: | 153.95 | 88.997 |
Precession in the alignment of the obliquity and eccentricity lead to global warming and cooling ('great' summers and winters) with a period of 170,000 years.
Like Earth, the obliquity of Mars undergoes periodic changes which can lead to long-lasting changes in climate. Once again, the effect is more pronounced on Mars because it lacks the stabilizing influence of a large moon. As a result the obliquity can alter by as much as 45°. Jacques Laskar, of France's National Centre for Scientific Research, argues that the effects of these periodic climate changes can be seen in the layered nature of the ice cap at the Martian north pole. Current research suggests that Mars is in a warm interglacial period which has lasted more than 100,000 years.
Because the Mars Global Surveyor was able to observe Mars for 4 Martian years, it was found that Martian weather was similar from year to year. Any differences were directly related to changes in the solar energy that reached Mars. Scientists were even able to accurately predict dust storms that would occur during the landing of Beagle 2. Regional dust storms were discovered to be closely related to where dust was available.
Read more about this topic: Climate Of Mars
Famous quotes containing the word seasons:
“Sorrow breaks seasons and reposing hours,
Makes the night morning and the noontide night.”
—William Shakespeare (1564–1616)
“The men who think of superannuation at sixty-one are those whose lives have been idle, not they who have really buckled themselves to work. It is my opinion that nothing seasons the mind for endurance like hard work. Port wine should perhaps be added.”
—Anthony Trollope (1815–1882)
“There is no single face in nature, because every eye that looks upon it, sees it from its own angle. So every mans spice-box seasons his own food.”
—Zora Neale Hurston (1891–1960)