Earth Science: Geology, the Environment, and the UniverseChapter 14:
ClimateProblem of the WeekLife: What’s Eccentricity Got To Do With It? Scientists speculate that the nearly circular orbit of Earth provides
a more constant, stable influx of solar energy, and therefore, a more
stable global climate. Planets with more elliptical orbits may have more
extreme or variable climates depending on the degree of eccentricity.
Due to the difficulty in detecting the small gravitational effects, many
of these planets are larger than Jupiter. Some scientists are confident
that smaller planets exist and that their orbits may not be as elliptical
as the currently known extra-solar planets. Students should infer that the more circular an orbit, the more constant
the influx of solar radiation resulting in a fairly stable global climate.
Distance from the star is also a factor. Look at Venus for example. This
planet has the most eccentric orbit, and it does have a fairly stable
planetary climate. However, it is a severe climate–one not conducive to
life as we know it. Students should infer that distance is another factor.
Resources: - Gale
Group (2000).
Elliptical orbits may be planetary norm. Science News. Dec 11, 1999.
- Orbits
of other distant planets oval - not circular, January 9, 1999.
Public Affairs Office at San Francisco State University, Diag Center.
- Glennda
Chui (2000).
Small Worlds, After All. Mercury News.
*A general description of how scientists infer that a planet exists.
- Space
Link: Charting the Planets.
Education Division. NASA.
- Interactive
Investigation Of The Shapes Of Planetary Orbits.
* Contains a great activity for investigating orbital eccentricity.
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