Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, a blanketing atmosphere and a protective magnetic field. A new study of the young, Sun-like star Kappa Ceti shows that a magnetic field plays a key role in making a planet conducive to life.
New and very precise observations using the HARPS spectrograph with the ESO 3.6-metre telescope in Chile have not only detected the motion of the enigmatic bright spots on Ceres due to the dwarf planet’s rotation about its axis, but also found unexpected additional variations suggesting that the material of the spots is volatile and evaporates in sunlight.
In June 2015, V404 Cygni underwent dramatic brightening for about two weeks, as it devoured material that it had stripped off an orbiting companion star. Violent red flashes, lasting just fractions of a second, were observed during the flare-up — one of the brightest black hole outbursts in recent years.
Shortly to be honoured with a Bessel Award of the Humboldt Foundation, Professor Harald Pfeiffer’s research into solving Einstein’s equations on supercomputers not only helps us locate black holes in the Universe and determine their size, but his calculations also teach us how space-time behaves when it is warped by black holes.
Indisputable physical calculations state that approximately 27 percent of the universe is dark matter, but there are indications that we might never see it. Now researchers in Denmark turn this somehow depressing scenario into an advantage and propose a new model for what dark matter might be — and how to test it.
Galaxy clusters are enormous collections of hundreds or even thousands of galaxies and vast reservoirs of hot gas embedded in massive clouds of dark matter. To learn more about clusters, including how they grow via collisions, astronomers have used some of the world’s most powerful X-ray, optical and radio telescopes. The name for this galaxy cluster project is the “Frontier Fields”.
Similar in many ways, Saturn’s moons Tethys and Rhea (left and right, respectively) even share a discoverer: Giovanni Cassini, namesake of the NASA spacecraft that captured this view. Although somewhat different in size, Rhea (949 miles across) and Tethys (660 miles) are both composed largely of ices and are generally thought to be geologically inactive today.
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