WHAT'S INSIDE: ASTRONOMY
- The Solar System
Do the two meet for one final, fantastic explosion? Or maybe the sun just gets a bit of wind? Or maybe nothing of consequence happens at all? Only one way to find out.
Neptune is the eighth planet from the sun, the fourth largest, and a gas planet. It is named after the Roman god of the sea. Neptune is four times the size of Earth, and its day lasts a little more than16 hours. Its year is about 165 Earth years. Neptune's orbit is a perfect circle. The last stop on spacecraft Voyager's epic trip through the solar system was the gas giant Neptune.