Heavens

For the first time ever, astronomers have observed both gravitational waves and light (electromagnetic radiation) from the same event, thanks to a global collaborative effort and the quick reactions of both ESO's facilities and others around the world.

Like most solar sounding rockets, the second flight of the FOXSI instrument - short for Focusing Optics X-ray Solar Imager - lasted 15 minutes, with just six minutes of data collection. But in that short time, the cutting-edge instrument found the best evidence to date of a phenomenon scientists have been seeking for years: signatures of tiny solar flares that could help explain the mysterious extreme heating of the Sun's outer atmosphere.

When the total solar eclipse swept across the United States on Aug. 21, 2017, NASA satellites captured a diverse set of images from space. But days before the eclipse, some NASA satellites also enabled scientists to predict what the corona -- the Sun's outer atmosphere -- would look like during the eclipse, from the ground. In addition to offering a case study to test our predictive abilities, the predictions also enabled some eclipse scientists to choose their study targets in advance.

At any given moment, as many as 10 million wild snakes of solar material leap from the sun's surface. These are spicules, and despite their abundance, scientists didn't understand how these jets of plasma form nor did they influence the heating of the outer layers of the sun's atmosphere or the solar wind. Now, for the first time, in a study partly funded by NASA, scientists have modeled spicule formation.

The quest to discover how planets found in the far reaches of the universe are born has taken a new, crucial twist.

A new study by an international team of scientists, led by Stefan Kraus from the University of Exeter, has given a fascinating new insight into one of the most respected theories of how planets are formed.

Young stars start out with a massive disk of gas and dust that over time, astronomers think, either diffuses away or coalesces into planets and asteroids.

Scientists have long assumed that all the planets in our solar system look the same beneath the surface, but a study published in Geology on Oct. 4 tells a different story.

"The mantle of the earth is made mostly of a mineral called olivine, and the assumption is usually that all planets are like the Earth," said Jay Melosh, Distinguished Professor of Earth, Atmospheric and Planetary Sciences at Purdue University, who led the study. "But when we look at the spectral signature of rocks exposed deep below the moon's surface, we don't see olivine; we see orthopyroxene."

In November 1572 a supernova explosion was observed in the direction of the constellation of Cassiopeia, and its most famous observer was Tycho Brahe, one of the founders of modern observational astronomy. The explosion produced an expanding cloud of superhot gas, a supernova remnant which was rediscovered in 1952 by British radioastronomers, confirmed by visible photographs from Mount Palomar observatory, California, in the 1960's, and a spectacular image was taken in X-rays by the Chandra satellite observatory in 2002 (see accompanying image).

A postgraduate of the Faculty of Geology at Moscow State University working as a part of an international team has assessed the oxidative environment and its changes inside asteroids from the core to the surface. This gives the authors of the study a better understanding of how the planets were formed. The paper was published in Meteoritics and Planetary Science.

Black holes are the final stage in the evolution of the most massive stars. Some black holes form a pair, orbiting around each other and gradually getting closer while losing energy in the form of gravitational waves, until a point is reached where the process suddenly accelerates. They then end up coalescing into a single black hole. Merging black holes have already been observed three times by the LIGO detectors, in 2015 and early 2017 . This time, three instruments detected the event on 14 August 2017 at 10:30 UTC, enabling vastly improved localization in the sky.

For the first time, three detectors have tracked the gravitational waves emitted by a merger of two black holes -- a critical new capability that allows scientists to more closely locate a gravitational wave's birthplace in space. Gravitational waves are ripples in space and time created when two massive, compact objects such as black holes merge.