Researchers analysing nearly 1,000 ice grains detected by NASA's Cassini spacecraft have uncovered unexpected chemical diversity in material originating from Enceladus' subsurface ocean. Laboratory experiments at ELSI show how salts can separate as ocean droplets slowly freeze. The researchers propose that these larger frozen droplets later shatter within the moon's icy vents, producing chemically distinct particles that are ejected into space.

The CHIME telescope has made its first standalone detection of the glow of hydrogen from when the universe was about five billion years old, paving the way for new studies of cosmic expansion and dark energy.

With a global ocean of liquid water below a thick crust of ice, Saturn’s moon Enceladus is one of the most promising places to search for life beyond Earth. A new study suggests the moon itself may aid in that search by making some ocean compounds easier for future spacecraft to detect. 

The vacuum is not always so empty. “When we talk about a vacuum in cosmology, we do not mean completely devoid of energy,” explains David Wands, Professor at the Institute of Cosmology & Gravitation at the University of Portsmouth. “A vacuum is rather a state in which a field sits at a minimum of its energy. The true vacuum is the lowest possible minimum, but there can also be local minima, which we call false vacua.” We can picture this as a landscape made up of valleys of different depths: the true vacuum is the deepest one, while the others are false vacua. Something sitting in one of these depressions can remain “trapped” there even if, somewhere else, a lower-energy state exists. This is exactly what can happen to quantum fields, fundamental physical objects that permeate the Universe. A classical field is something that has a value at every position in space, like a magnetic field, whose strength changes from point to point. Quantum fields behave in a similar way, and their excitations appear as particles. In a new study published in JCAP, Robson Christie, Jaewoo Joo, Greg Kaplanek, Vincent Vennin and David Wands used a simplified model to investigate what determines which vacuum a field may end up in within an expanding Universe.