Mercury, the Closest Planet to the Sun
Mercury is the planet that is closest to the Sun. Mercury is 29 million miles away from the Sun. Once again, a distance like that sounds huge, but Mercury is still much closer to the Sun than all the other planets in the solar system. Since Mercury is so close to the Sun, the Sun appears about three times larger on Mercury than it does here on Earth. Below is a photo that shows how close Mercury is to the Sun.
What Makes up Mercury?
Mercury is made of rock and has an iron core. Mercury also has many craters, similar to ones that are on the Moon. Ice has also been found on Mercury. This surprised scientists because Mercury is so close to the Sun. However, the ice is located at both poles of Mercury where the Sun does not shine. Take a look at the picture below which shows what makes up Mercury.
How Big is Mercury?
Mercury is the smallest planet. It is just about as big as the Moon. Three Mercury's would be able to fit inside the Earth! Mercury's close location to the Sun and its small size make it hard to see in the sky without a telescope. The photo below shows the size of Mercury compared to our planet Earth.
Does Mercury Have an Atmosphere?
Mercury does not have an atmosphere. This allows temperatures to get dangerously high during the day and dangerously cold at night because there is no blanket of insulation over Mercury. Also, the lack of atmosphere means there is no weather on Mercury and no liquid water. On planets with no atmosphere, the sky is black even in the daytime. On Mercury, the Sun is visible during the day, but the rest of the sky is still black! Look at the photo below, it is what daytime would look like on Mercury.
How Long Does it Take Mercury to Orbit Around the Sun?
It only takes Mercury 88 days to travel around the Sun. Remember it takes the Earth 365 days to travel around the Sun. Mercury Orbits the Sun faster because it is closer to the Sun and feels more gravitational pull from it.
Take a look at the videos below about Mercury. The first video deals with many things we have learned about Mercury. The second video is about a current mission to Mercury that N.A.S.A. is doing. If Space exploration interests you, you'll enjoy the second video.
Time to Share!
Write a paragraph to people on Earth describing at least three characteristics that you have learned about Mercury on your journey.