Two New Moons for Jupiter 

With the addition of two newly discovered moons, Jupiter is now home to 69 known satellites. The new moons, S/2016 J 1 and S/2017 J 1, were announced through the Minor Planet Electronic Circulars on June 2^nd and June 5^th, respectively.

S/2016 J 1 was discovered on March 8, 2016 at the Las Campanas Observatory in Chile. The moon orbits far from Jupiter, at an average distance of 20,600,000 km and taking 1.65 years to orbit the planet.

The other moon, S/2017 J 1, was discovered on March 23, 2017 at the Cerro Tololo Inter-American Observatory, also in Chile. It orbits further than the other moon at 23,500,000 km every 2.01 years.

Just like most of Jupiter’s moons, these two have retrograde orbits, meaning they move in the opposite direction that Jupiter spins. It is believed that satellites with retrograde orbits were formed elsewhere in the Solar System and have been captured by the planet’s gravity when passing by.

Images: The discovery images of the new Jovian satellites S/2016 J 1 (left) and S/2017 J 1 (right). Credit: Scott Sheppard

s-c-i-guy:

The Nobel Prize in Physics 2016 – David J. Thouless, F. Duncan M. Haldane, J. Michael Kosterlitz – “for theoretical discoveries of topological phase transitions and topological phases of matter”

They revealed the secrets of exotic matter

This year’s Laureates opened the door on an unknown world where matter can assume strange states. They have used advanced mathematical methods to study unusual phases, or states, of matter, such as superconductors, superfluids or thin magnetic films. Thanks to their pioneering work, the hunt is now on for new and exotic phases of matter. Many people are hopeful of future applications in both materials science and electronics.

The three Laureates’ use of topological concepts in physics was decisive for their discoveries. Topology is a branch of mathematics that describes properties that only change step-wise. Using topology as a tool, they were able to astound the experts. In the early 1970s, Michael Kosterlitz and David Thouless overturned the then current theory that superconductivity or suprafluidity could not occur in thin layers. They demonstrated that superconductivity could occur at low temperatures and also explained the mechanism, phase transition, that makes superconductivity disappear at higher temperatures.

In the 1980s, Thouless was able to explain a previous experiment with very thin electrically conducting layers in which conductance was precisely measured as integer steps. He showed that these integers were topological in their nature. At around the same time, Duncan Haldane discovered how topological concepts can be used to understand the properties of chains of small magnets found in some materials.

We now know of many topological phases, not only in thin layers and threads, but also in ordinary three-dimensional materials. Over the last decade, this area has boosted frontline research in condensed matter physics, not least because of the hope that topological materials could be used in new generations of electronics and superconductors, or in future quantum computers. Current research is revealing the secrets of matter in the exotic worlds discovered by this year’s Nobel Laureates.

houghtonlib:

Galileo didn’t know it at the time, but his observations of sunspot activity in 1612 were tailor-made for the animated GIF! He demonstrated that sunspots can be tracked across the disk of the sun as it rotates–look for the cluster labeled R moving from top left to lower right.

Galilei, Galileo, 1564-1642. Istoria e dimostrazioni intorno alle macchie solari e loro accidenti, 1613.

*IC6.G1333.613ia 

Houghton Library, Harvard University