Thanks to Marc Morano for sending me the National Geographic article ‘Mars, Like Earth, Has Cyclical Ice Ages, Study Says’ relating to a new nature paper entitled ‘Dynamics of ice ages on Mars.’
Mars has gone through 40 ice ages during the past five million years that regularly send the planet’s permanent ice sheets cascading toward the equator, then melting backward, a new theory suggests.
The climate changes are likely driven by cyclical fluctuations in the planet’s orbit that alter the amount of sunlight that falls on the planet’s surface, says astronomer Norbert Schörghofer of the University of Hawaii at Manoa.
Understanding the sun’s exact role in the Martian ice ages could help solve longstanding puzzles about the red planet.
It could also help scientists better understand Earth’s complex climatic systems, which are also affected by orbital variations.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Yes. What is his point? At the moment, Milankovich is not a factor on Earth.
SJT, what an idiotic statement to make that “At the moment, Milanchovic is not a factor on earth”.
The variations in the earth’s orbit, which together make up what is referred to as the Milankovic cycles are always in operation. The eccentricity, axial tilt, and precession of the Earth’s orbit are always changing the level and distribution of insolation on the earth’s surface. Sometimes they act against each other, at other times they act together. The total effect of the three variations repeats itself about every 100,000 years, which is referred to as the Milankovic cycles.
The variation in effect on the earth’s surface is further compounded by the difference in distribution of the continents between the northern and southern hemispheres.
Go away and study basic astrophysics 101.
OK PP the point is a bit short but he’s right in that there’s no rapid change that adds up to be forcing change in the 100-200 year sense. Is there?
Mars I’m not sure – different planet – different orbit. Someone might tell us how often Mars varies its orbit and how. In terms of eccentricity, obliquity, and precession.
Well since this is my schickt. Mars and Earth have both gone through the last 100,000 years of ice age and worm periods together, concurrently, in unison, hand in hand, as if their were some larger force that controls the thermostat for our solar system. Milankovitch be damned.
James, don’t you know how it works yet? Any position is worth holding, as long as it doesn’t agree with Anthropogenic Global Warming.
SJT, I have no doubt about how Mars and Earth managed to heat up and freeze down at the same time. The only thing I wonder at is how a person such as yourself will grasp at any idea that “proves” mankind a plague on the planet.
Why is that?
Has it? How long has Mars been warming?
How long has Mars climate been warming?
Here’s a paper from Jan 1975, titled Climatic change on Mars and Earth.
Couldn’t be retrived online but here is the abstract:
Work on climatic changes of Mars is reviewed and related to terrestrial problems. In particular the dust storms of Mars are discussed since these represent the only global climatic change which has been scientifically observed. The channels of Mars have provoked studies of climatic change and these are summarized together with polar laminae as a climatic change indicator.
http://ntrs.nasa.gov/search.jsp?R=31134&id=10&qs=No%3D40%26N%3D4294958487
Authors: Toon, O. B.; Sagan, C.; Gierasch, P. J.; Pollack, J. B.
Couple famous luminaries.