to explain the motion of planets, especially the phenomenon of retrograde motion where planets appear to temporarily reverse their direction of motion. Ref: Andrew Liddle "An Introduction to modern Cosmology".
Mass does not change with gravity. Weight increases on BIGGER planets and decreases on smaller planets.
Yes, the inner planets (Mercury, Venus, Earth, and Mars) are smaller than the outer planets (Jupiter, Saturn, Uranus, and Neptune). The outer planets are known as gas giants and are much larger in size compared to the inner terrestrial planets.
No. Planets orbit suns, while moons orbit planets. Planets do not orbit planets.
The planets appear smaller than the sun because they are much smaller in size compared to the sun. Even though they may be further away, it is primarily their smaller size that makes them look smaller in the sky.
The inner planets, also called terrestrial planets, are closer to the Sun and have solid surfaces, while the outer planets, known as gas giants, are farther from the Sun and composed mostly of gas. Inner planets are smaller and have higher densities, while outer planets are much larger and have lower densities. Additionally, inner planets have few or no moons, while outer planets have numerous moons.
ptolemy did something
Ptolemy's model, known as the geocentric system, aimed to explain the complex movements of planets, particularly their retrograde motion, using a series of circles. By proposing that planets moved on smaller circles called epicycles, which in turn moved along larger circles (deferents), he sought to account for the observed irregularities in their paths while maintaining the Earth at the center of the universe. This intricate system allowed for more accurate predictions of planetary positions, reflecting the astronomical knowledge of his time.
Ptolemy is trying to explain in his model that each circle represents 1 planet's rotation and it's a scale drawing of the distance apart from each one!
Ptolemy proposed the use of epicycles (small circles) within deferents (larger circles) to explain the observed retrograde motion of planets. The epicycles were used to account for the variability in a planet's speed as it moved along the deferent in his geocentric model.
Mercury circles the sun in 88 days. That is the fastest orbiting planet. It is because of it's position with the sun. It is the closest so it has a smaller orbit.
smaller
Mass does not change with gravity. Weight increases on BIGGER planets and decreases on smaller planets.
yes because one is smaller than the other
No. All of the objects in out solar system labeled as dwarf planets are smaller than the smallest of the planets. The gas planets are the largest planets.
Objects that are smaller than planets are called "dwarf planets"; even smaller objects are called "asteroids".
dwarf planets are smaller than regular planets
Yes, the inner planets (Mercury, Venus, Earth, and Mars) are smaller than the outer planets (Jupiter, Saturn, Uranus, and Neptune). The outer planets are known as gas giants and are much larger in size compared to the inner terrestrial planets.