Achernar, a blue-white star in the constellation Eridanus. Achernar has an apparent magnitude of 0.5, making it one of the brightest stars in the nighttime sky. It is visible only from locations south of about 32 North latitude. The star has an absolute magnitude of -2.3 and is approximately 118 light-years from the earth.
A billion years ago, the moon stopped being geologically active. But that's not to say that the moon is doing nothing for us. Let's find out why we owe our moon some thank-yous.
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.