UNIVERSE
SURVEY OF THE PLANETS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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planets move on epicycles.
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planets orbit the Sun in the same direction.
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Earth moves faster in its orbit.
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they rotate quickly on their axes.
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Detailed explanation-1: -Mars, Jupiter, & Saturn show Retrograde Motion because As Earth overtakes and “passes” the outer planets, they seem to slow down & then reverse direction.
Detailed explanation-2: -It’s an illusion, caused by the ways that Earth and Mars orbit the sun.
Detailed explanation-3: -Mars and Saturn don’t actually reverse direction in their orbits. Instead, their apparent backwards or retrograde motion with respect to the background stars is a reflection of the orbital motion of the Earth itself.
Detailed explanation-4: -Jupiter is following a roughly circular orbit around the Sun, but it takes 12 years to complete an orbit; while Earth takes just a year for an orbit. The retrograde motion of Jupiter actually comes from Earth catching up to Jupiter in its orbit. As Earth passes Jupiter in orbit, we’re looking back at it as we go by.
Detailed explanation-5: -Planets typically move toward the east in front of the stars. When they move west, they’re said to be undergoing retrograde motion. The illusion is caused by our perspective, as seen from Earth.