NASA scientists say that there were once thousands of volcanic eruptions on Mars. These explosive blasts, in the northern Arabia Terra region, were "super eruptions," the largest and most powerful kind known. The intense activity continued for about 500 million years, about four billion years ago.

Delta Cephei is an inconspicuous variable star in the northern constellation Cepheus the King. This star helps establish the cosmic distance scale.

The Juno spacecraft observed footprint tails of aurora on Jupiter’s atmosphere. Three of Jupiter’s closest large moons create these auroral tails.

Scientists in the U.K. have developed a kind of "space concrete" using dust and human blood that could be used for future human habitats on Mars or the moon.

Pablo Neruda was a famous Chilean poet who wrote: "Every day you play with the light of the universe." Neruda died on this date, September 23, in 1973.

The equinox is September 22. From around the world on the day of an equinox, the equinox sun pretty much rises and sets due east and west.

The Bible story of Sodom and Gomorrah describes ancient cities destroyed for their wickedness. New research suggests a meteor impact instead.

Gamma Cephei - or Errai - is a binary star system that will someday be Earth’s North Star. Gamma Cephei is home to the first exoplanet ever discovered.