Historical ObservationsMain article: History of Mars observation
The history of observations of Mars is marked by the oppositions of Mars, when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars which occur every 15 or 17 years, and are distinguished because Mars is close to perihelion, making it even closer to Earth.
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Other articles related to "historical observations":
... Historical observations of the carnivorous syndrome in plant species have been restricted to the more obvious examples of carnivory, such as the active trapping mechanisms of Drosera and Dionaea, though authors ...
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“All observations point to the fact that the intellectual woman is masculinized; in her, warm, intuitive knowledge has yielded to cold unproductive thinking.”
—Helene Deutsch (18841982)
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