Astronomy
...tion: Axial inclination is the angle at which a planet's axis of rotation is tilted, with respect to that planet's own orbit. On Earth, as well as other planets, this tilt is responsible for the seasons. Average temperature: Given in degrees centigrade. Black Hole: The remains of the death and collapse of an extremely massive star. The gravitational pull of a black hole is so strong that light itself cannot escape. Earth: Third planet from the Sun Jupiter: Fifth planet from the Sun Mass: The mass is a measure of how much 'stuff' something contains. This shouldn't be confused with weight, which is a measure of the force of gravity on an object. An apple weighs more on Jupiter than it does on Earth because Jupiter's gravity is stronger. However, the apple always has the same mass, no matter where it is. We can't measure the weight of a planet simply because in space, the concept of weight is meaningless! Weight is measured in terms of the attraction of one body to another. In other words, in order to "weigh" Jupiter, you'd have to have it sitting on a scale on the Earth! Mars: Fourth planet from the Sun. Mercury: Closest planet to the Sun. Neptune: Eighth planet from the Sun (usually) Orbital inclination: The orbits of the planets are tilted with respect to each other. Orbital inclination is a measure of the orbit's tilt with respect to the Earth's orbit. Orbital period: The length of time for a planet to circle the Sun is known as its orbital peri...