Category Astronomy/Space

This simulation shows how two galaxies merge over a period of 15 millionen years. The red and the blue dots illustrate the two black holes (image: Astrophysical Journal).

If two galaxies collide, the merging of their central black holes triggers gravitational waves, which ripple throughout space. An international research team involving the University of Zurich has now calculated that this occurs around 10 million years after the two galaxies merge – much faster than previously assumed.

In his General Theory of Relativity, Albert Einstein predicted gravitational waves over a century ago; this year, they were detected directly for the first time: The American Gravitational Wave Observatory LIGO recorded such curvatures in space from Earth, which were caused by the merging of two massive b...

Cosmic reionisation. Credit: ESA – C. Carreau

ESA’s Planck satellite has revealed that the first stars in the Universe started forming later than previous observations of the Cosmic Microwave Background, CMB indicated. This new analysis also shows these stars were the only sources needed to account for reionising atoms in the cosmos, having completed half of this process when the Universe had reached 700 million years.

With the multitude of stars and galaxies that populate the present Universe, it’s hard to imagine how different our 13.8 billion year cosmos was when it was only a few seconds old. At that early phase, it was a hot, dense primordial soup of particles, mostly electrons, protons, neutrinos, and photons – particles of light...

NASA’s Juno spacecraft captured this view as it closed in on Jupiter’s north pole, about two hours before closest approach on Aug. 27, 2016. Credit: NASA/JPL-Caltech/SwRI/MSSS

NASA’s Juno spacecraft has sent back the 1st-ever images of Jupiter’s north pole, taken during the spacecraft’s first flyby of the planet with its instruments switched on. The images show storm systems and weather activity unlike anything previously seen on any of our solar system’s gas giant planets. Juno successfully executed the first of 36 orbital flybys on Aug. 27 when the spacecraft came about 2,500 miles above Jupiter’s swirling clouds. The download of 6 Mb of data collected during the 6h transit, from above Jupiter’s north pole to below its south pole, took one and a half days...

You can tell Earth and the moon’s shadows apart by their edges: Earth’s is fuzzy, while the moon’s is sharp and distinct. This is because Earth’s atmosphere absorbs some of the sun’s light, creating an ill-defined edge. On the other hand, the moon has no atmosphere, producing a crisp horizon. Credit: NASA/SDO

Early in the morning of Sept. 1, 2016, NASA’s Solar Dynamics Observatory, or SDO, caught both Earth and the moon crossing in front of the sun. SDO keeps a constant eye on the sun, but during SDO’s semiannual eclipse seasons, Earth briefly blocks SDO’s line of sight each day – a consequence of SDO’s geosynchronous orbit. On Sept. 1, Earth completely eclipsed the sun from SDO’s perspective just as the moon began its journey across the face of the sun...