Neptune: The Big Blue Planet

Overview

Neptune is the eighth planet from the Sun and is the most distant planet in our solar system. More than 30 times as far from the Sun as Earth, Neptune is the only planet in our solar system not visible to the naked eye.

Description

Neptune is formed around 4.5 billion years ago. With a radius of 15,299.4 miles (24,622 kilometers), Neptune is about four times wider than Earth. From an average distance of 2.8 billion miles (4.5 billion kilometers), Neptune is 30 astronomical units away from the Sun.*. It takes about 4 hours for light from the Sun to reach Neptune.

Potential for Life:
Neptune's environment is not too conducive to life as we know it. The temperatures, pressures and materials are most likey too extreme and volatile for living organisms to adapt to.

Orbit and Rotation:
A day on Neptune takes about 16 hours, and completes an orbit around the Sun in about 165 Earth years. Sometimes Neptune is even farther from the Sun than dwarf planet Pluto. Pluto's highly eccentric, oval-shaped orbit brings it inside Neptune's orbit for a 20-year period every 248 Earth years. Saturn's axis of rotation is tilted by 28 degrees, which is similar to Earth's. Since the year is so long, each of the four seasons lasts for over 40 years.

Structure:
Neptune is one of the two ice giants in the outer solar system. 80% or more of its mass is made up from hot dense fluid of "icy" materials - water, methane and ammonia. Of all the giant planets, Neptune is the densest.

Temperatures:
The temperature on Neptune is around minus 189 degrees Celsius (minus 373 degrees Fahrenheit), with its largest moon, Triton, having a temperature of minus 199 degrees Celsius (391 degrees Fahrenheit), holding the record of the coldest temperature measured in the solar system.

Surface:
As a gas giant, Neptune doesn’t have a true surface. The planet is mostly swirling gases and liquids deeper down.

Atmosphere:
Neptune's atmosphere is made up mostly of hydrogen and helium with a little bit of methane. Neptune is our solar system's windiest world, with wind speeds of more than 1,200 miles per hour (2,000 kilometers per hour). Its winds can be three times stronger than Jupiter's and nine times stronger than Earth's.

Magetosphere:
The main axis of Neptune's magnetic field is tipped over by about 47 degrees compared with the planet's rotation axis. The magnetic field of Neptune is about 27 times more powerful than that of Earth

Moons:
Neptune as 14 known moons. With its largest moon being Triton. Triton is the only large moon in the solar system that circles its planet in a direction opposite to the planet's rotation. Triton is extremely cold, and yet, despite this deep freeze at Triton, Voyager 2 discovered geysers spewing icy material upward more than 5 miles (8 kilometers).

Rings:
Neptune has at least five main rings and four prominent ring arcs that we know of so far. **.

Fun Facts!

• Neptune is the smallest of the gas giants.
• There are no plans to visit Neptune again.
• Neptune is the last discovered planet in our solar system.
• Neptune is named after the Roman god of water and seas, Neptune.

Footnotes:

*One astronomical unit (abbreviated as AU), is the distance from the Sun to Earth.

**The rings are name alphabetically in the order they were discovered. The main rings are A, B, and C. Rings D, E, F, and G are fainter and more recently discovered.