A galaxy is a huge collection of gas, dust, billion of stars and their solar systems.

Spacecraft

A Spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purpose, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans or cargo.

Moon

The moon is made of rocks and soil. It orbits the Earth as is its only natural satellite. It is the fifth-largest satellite in the solar system.

St rs

Stars are giant spheres of plasma. There are billions of them, including our own sun, in the Milky Way galaxy.

Earth

Earth, our home, is the third planet from the sun. It's the only known planet to have an atmosphere containing free oxygen, oceans of water on its surface, and, of course, life. Earth is the fifth largest of the planets in the solar system.....about 1/5 of the Earth's atmosphere consists of oxygen produced by plants.

Mars

Mars is the fourth planet from the sun and the second- smallest planet in the solar system after Mercury. Mars is a terrestrial planet with a thin atmosphere, having a surface similar to the craters in the moon and the valleys, deserts, and polar ice caps of Earth.

Mercury

Mercury is the smallest planet in our solar system. Along with Venus, Earth, and Mars, Mercury is one of the rockiest planets. It has a solid surface that is covered with craters. It has a thin atmosphere, and it doesn't have any moons.

Venus

Even though Venus isn't the closest planet to the sun, it is still the hottest. It has a thick atmosphere full of greenhouse gas and carbon dioxide.

Greenhouse Effect

For a really strong greenhouse effect, we should look at Venus. Venus is similar to earth in terms of size and mass, but its surface temperature is about 460 degrees.