PLEASE HELP Explain why the outer planets did not lose the lighter gasses in the atmosphere.
the outer planets are bigger and have stronger gravities that are able to hold the lighter gases
they are more massive (heavier) than the inner planets; and their greater gravities allow them to hold the lighter gasses
thank you scott
The outer planets in our solar system, also known as the gas giants, are Jupiter, Saturn, Uranus, and Neptune. These planets have much thicker atmospheres compared to the inner rocky planets like Earth, Mars, Venus, and Mercury. The primary reason why the outer planets did not lose the lighter gases in their atmospheres can be attributed to their much stronger gravitational pull.
To understand this, let's delve into the concept of escape velocity. Escape velocity is the minimum velocity an object needs to overcome the gravitational attraction of a planet or celestial body and escape into space. The escape velocity depends on the mass and radius of a planet. The larger the mass and radius, the stronger the gravitational pull and the higher the escape velocity required.
The gas giants have considerably larger masses and radii compared to the inner planets. For example, Jupiter, the largest planet, is about 318 times more massive than Earth and has a radius eleven times that of Earth. Saturn, Uranus, and Neptune also have comparable large sizes.
Due to their enormous size and mass, the escape velocity on the gas giants is much greater than the velocities of most gas molecules, including lighter gases like hydrogen and helium. As a result, it becomes extremely difficult for these gases to achieve escape velocity and escape into space. Instead, they remain trapped within the gravitational pull of the planet, resulting in a thick and dynamic atmosphere.
In addition to their higher escape velocity, the outer planets also have lower temperatures compared to the inner planets. The colder temperatures at these distances from the Sun allow the lighter gases to condense and form part of the planetary atmospheres, rather than being lost to space.
Therefore, the combination of the gas giants' massive sizes, high escape velocities, and cooler temperatures contributes to their ability to hold onto the lighter gases in their atmospheres, preventing significant losses.