Difference Between Mercury And Venus
To the ancient Romans, Mercury was the swift messenger of the gods. This was certainly a good name to give to the small planet closest to the sun. Of the eight planets in the solar system, the planet Mercury travels around the sun the fastest. It completes one full orbit in only 88 Earth days. This is less than one-fourth the time the Earth takes to orbit the sun.
Mercury is not easy to see from the Earth because it lies so close to the sun. It can only be observed as a faint starlike object appearing near the horizon during the twilight hours just after sunset or just before sunrise. Even astronomers with large telescopes can see little of the planet. Mercury is just too small and too far away for telescopes on Earth to observe much of it.
Most of Mercury’s craters were caused by large meteorites that crashed into the planet’s surface between 3.7 and 4.5 billion years ago. This period is known as the Great Bombardment. It occurred early in the history of the solar system. It also left craters on the Earth’s moon and on many other objects in the solar system.
There are some differences between the craters on Mercury and those on the Earth’s moon. Most of Mercury’s craters are flatter and have thinner rims or walls. This may be because the force of gravity is greater on Mercury than it is on the moon. A stronger gravitational force may have caused the crater rims on the planet to crumble somewhat. By observing how some of Mercury’s craters lie inside or on top of others, scientists can determine which craters formed first. This can help them understand something about how the planet and its surface features evolved.
Venus, the second planet in the solar system, after Mercury, in order of increasing distance from the sun. Venus has no known satellites.
Venus can be seen near the horizon within a few hours of sunrise or sunset. It can appear as a “morning star,” rising earlier than the sun, before superior conjunction; or it can appear as an “evening star,” setting later than the sun, after superior conjunction. (A “superior conjunction” occurs when the earth, the sun, and Venus align with Venus on the far side of the sun from the earth; the conjunction is “inferior” when the three align with Venus between the earth and the sun.)