Mercury's atmosphere is primarily made up of oxygen, potassium, sodium, helium and hydrogen. The atmosphere on Mercury is made up of atoms that are launched from the planet's surface from micrometeoroid impacts and solar... More » Science Astronomy Planets

Mercury has a large metallic core with a relatively thin rocky crust and mantle that has a high abundance of sulfur and potassium. Its magnetic field is off-center, which indicates that its internal structure is complex ... More »

There is no weather on Mercury because Mercury doesn't have much of an atmosphere. There is no wind, rain, snow, storms or clouds. However, during the day, the temperature can soar to 800 degrees Fahrenheit. At night, th... More »

The atmosphere for the planet Uranus is made up of methane, helium and hydrogen. Uranus is considered unique as it tilts at a 98 degree angle, and when the planet is seen from Earth, it looks like it rotates on its side. More »

As a gas giant, Neptune is primarily made from hydrogen, measured at 80 percent of the atmosphere, with an additional 19 percent composed of helium. The remainder of the planet is mainly composed of small amounts of meth... More » Science Astronomy Planets

Saturn's atmosphere is made up of about 75 percent hydrogen and 25 percent helium, along with trace amounts of water ice and other gases. Like the other planets in the outer solar system, Saturn is a gas giant that lacks... More »

Neptune's atmosphere is similar to the atmospheres of other large planets and contains helium and hydrogen. It also has trace amounts of water, ammonia, methane and other ices. More »