Geologists analyzed 40 meteorites that fell to Earth from Mars to understand the history of the Martian atmosphere. They show the atmospheres of Mars and Earth diverged in important ways early in the solar system's 4.6 billion year evolution.
This new image from ESO's La Silla Observatory in Chile reveals a cloud of hydrogen called Gum 41. In the middle of this little-known nebula, brilliant hot young stars are giving off energetic radiation that causes the surrounding hydrogen to glow with a characteristic red hue.
Much like an environment influences people, so too do cosmic communities affect even giant dazzling stars: Peering deep into the Milky Way galaxy's center from a high-flying observatory, astronomers have discovered identical, rare stars whose diverging dusty and gaseous garb are strictly influenced by an intrusive cluster of neighbors.
Created when an aging star blew off its outer layers, planetary nebula PN A66 33 is, by chance, aligned with a foreground star, and bears an uncanny resemblance to a diamond engagement ring. This cosmic gem is unusually symmetric, appearing to be almost circular on the sky.
An unusual structure with a hexagonal shape surrounding Saturn's north pole was spotted on the planet for the first time thirty years ago. Nothing similar with such a regular geometry had ever been seen on any planet in the Solar System.
Astronomers from the Sloan Digital Sky Survey have used 140,000 distant quasars to measure the expansion rate of the Universe when it was only one-quarter of its present age. This is the best measurement yet of the expansion rate at any epoch in the last 13 billion years.
Mapping flood events, observing oil slicks in the oceans, detecting ice distribution in the sea and measuring ground movements with millimetric precision - just some of the tasks of Sentinel-1A, the new flagship in European Earth observation.