Two is company, but three might not always be a crowd, at least in space. When astronomers found an extrasolar planet orbiting a neighboring star, a detailed analysis of the data uncovered a third body. But astronomers couldn't definitively identify whether the object was another planet or another star in the system.
New findings from NASA's Hubble Space Telescope show suspected water plumes erupting from Jupiter's icy moon Europa. These observations bolster earlier Hubble work suggesting that Europa is venting water vapor. A team of astronomers, led by William Sparks of the Space Telescope Science Institute in Baltimore, Maryland, observed these finger-like projections while viewing Europa's limb as the moon passed in front of Jupiter. The team was inspired to use this observing method by studies of atmospheres of planets orbiting other stars.
Exoplanets: Migration of giants
Nature 537, 7621 (2016). doi:10.1038/nature19430
Authors: Amaury Triaud
The origin of hot Jupiters, large gaseous planets in close orbits around stars, is unknown. Observations suggest that such planets are abundant in stellar clusters, and can result from encounters with other celestial bodies.
Detailed map shows Milky Way is bigger than we thought
Nature 537, 7621 (2016). http://www.nature.com/doifinder/10.1038/nature.2016.20591
Author: Davide Castelvecchi
First results from Gaia probe also seem to solve old controversy over Pleiades cluster.
Astronomy: Universe much richer in galaxies
Nature 537, 7621 (2016). doi:10.1038/537453e
The observable Universe is populated by between 1 trillion and 3 trillion galaxies, almost 10 times more than previously estimated.A team led by Christopher Conselice at the University of Nottingham, UK, estimated this number using various telescope surveys that revealed evolving galaxy abundances since