Facts about Mercury
• First planet from the Sun
Diameter: 3,032 miles
Distance from Sun: 35,980,000 miles
Atmosphere: Mercury has no atmosphere.
Moons: Mercury has no moons.
The Challenge to See Mercury: Just to find and see Mercury with your eyes is almost a privledge because most people never get to glimpse this planet. Mercury hugs very close to the Sun, so you have to work fast just to see it after sunset or before sunrise because you don’t have much time before it is “lost.” At its brightest, it is fairly conspicious but time is limted before it sets or is lost in the glare of the Sun. Binoculars can be helpful to locate this illusive planet, enhancing what often escapes the attention of our eyes alone.
THE PLANET MERCURY
The planets were named after ancient Roman and Greek mythological gods. Mercury, the closest planet to the Sun, was identified with the Roman god who had wings attached to his feet and a helmet on his head. He swiftly delivered messages to the other gods. As the name so well implies, the planet Mercury revolves rapidly around the Sun, more swiftly than any of the others.
Mercury resembles our Moon. Like our Moon, it is small in size, pitted with craters, and has no atmosphere. Its craters were formed from a heavy bombardment of asteroids and comets during the first billion years of the solar system’s existence. The interior of Mercury, once molten, has cooled and is now solid. It is composed mostly of iron ore.
Since Mercury orbits inside Earth’s orbit, it cycles through phases like our Moon. When we see phases, we are seeing nothing more than the day and night sides of the planet at the same time.
Mercury in the sky
A false-color picture of Mercury to enhance a big impact basin (the yellowish part). Astronomers often colorize pictures to bring out detail.
When looking at the pictures above and below, one could mistake them for the Moon instead of Mercury because the two bodies are covered in craters, have plain-type areas and are appear crystal sharp because neither has an atmosphere.
What’s Out Tonight? is sponsored by Ken Press, publisher of astronomy books and charts.