A fresh look at data collected by NASA's Cassini spacecraft during its 2001 flyby of Jupiter shows that Europa's tenuous atmosphere is even thinner than previously thought and also suggests that the thin, hot gas around the moon does not show evidence of plume activity occurring at the time of the flyby. The new research provides a snapshot of Europa's state of activity at that time, and suggests that if there is plume activity, it is likely intermittent.
NASA's planet-hunting Kepler spacecraft makes a comeback with the discovery of the first exoplanet found using its new mission -- K2. The discovery was made when astronomers and engineers devised an ingenious way to repurpose Kepler for the K2 mission and continue its search of the cosmos for other worlds.
Scientists have solved a long-standing space mystery - the origin of the 'theta aurora'. Auroras are the most visible manifestation of the Sun's effect on Earth. They are seen as colorful displays in the night sky, known as the Northern or Southern Lights. They are caused by the solar wind, a stream of plasma - electrically charged atomic particles - carrying its own magnetic field, interacting with the earth's magnetic field. Normally, the main region for this impressive display is the 'auroral oval', which lies at around 65-70 degrees north or south of the equator, encircling the polar caps. However, auroras can occur at even higher latitudes. One type is known as a 'theta aurora' because seen from above it looks like the Greek letter theta - an oval with a line crossing through the center.
To paraphrase Mark Twain, the report of the Kepler spacecraft's death was greatly exaggerated. Despite a malfunction that ended its primary mission in May 2013, Kepler is still alive and working. The evidence comes from the discovery of a new super-Earth using data collected during Kepler's 'second life.'
An examination of middle-aged star clusters reveals an unexpectedly narrow age range among their stars, suggesting that large groups of stars evolve differently than previously understood.
Astronomers have discovered that modest black holes can shut down star formation by producing turbulence. High-energy jets powered by supermassive black holes can blast away a galaxy's star-forming fuel, resulting in so-called "red and dead" galaxies: those brimming with ancient red stars yet containing little or no hydrogen gas to create new ones.
Messier 47 is located approximately 1600 light-years from Earth, in the constellation of Puppis (the poop deck of the mythological ship Argo). It was first noticed some time before 1654 by Italian astronomer Giovanni Battista Hodierna and was later independently discovered by Charles Messier himself, who apparently had no knowledge of Hodierna's earlier observation. Although it is bright and easy to see, Messier 47 is one of the least densely populated open clusters. Only around 50 stars are visible in a region about 12 light-years across, compared to other similar objects which can contain thousands of stars.
New data shows Earth's oceans came from asteroids not comets. Also; Curiosity confirms Mars was once warm with regular wet seasons, and dark matter could be linked to a hypothetical subatomic particle called the sterile neutrino.
The closest planet to the sun appears to get hit by a periodic meteor shower, possibly associated with a comet that produces multiple events annually on Earth. The clues pointing to Mercury's shower were discovered in the very thin halo of gases that make up the planet's exosphere, which is under study by NASA's MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft.