Libra, a constellation and the seventh sign of the zodiac. The sun formerly entered Libra in autumn, when days and nights balance each other in length. The name Libra, meaning The Balance, probably refers to this fact. Libra is bordered by Serpens Caput on the north, by Ophiuchus and Scorpius on the east, by Lupus and Hydra on the south, and by Virgo on the west. Its brightest star, with a magnitude of 2.61, is Beta Librae, or Zubeneschamali. Alpha Librae is a double star whose components have magnitudes of 2.76 and 5.15.
Precipitation does fall from the clouds of other planets, but it's a little more exotic than the good, old-fashioned rainwater we get here on Earth. Imagine sheets of methane, sulfuric acid and, yes, even diamonds falling from the sky.
Since the 19th century, humans have wondered about the prospect of life on Mars. While we haven't sent anyone to the Martian surface, we have sent spacecrafts, which have gathered a good amount of information on what it's like on Mars. How is it different from Earth? How is it similar? And could life really have existed there long ago, or exist in the future?