Space

Jul 18 2021

Enceladus: Be careful when walking on ice

Anyone landing on Saturn's icy moon Enceladus, for example to explore the ocean at its depth, had better be careful: Ice quakes could be part of everyday life on the surface of the 500-kilometer-diameter moon. Researchers are drawing attention to this in a new study. The culprit is the massive tidal forces caused by Saturn and the planet's other, larger moons - much like the moon on Earth. These tidal movements, on the plus side, warm its interior so that life could possibly arise there. But they also cause the surface to crack, sometimes pushing large geysers of water…

Space

Jul 16 2021

Supernova due to overeating

Actually, a type Ia supernova is pretty nasty. The star that will eventually perish has basically done everything right and ended its long, modest life as a white dwarf. As such, it could continue to watch its fellow stars burn up for many billions of years - longer than the universe is old - if it didn't have a younger partner that was still in the prime of its life. Because if material flows from this other star to our white dwarf, an overshooting reaction likes to happen. The (former) white dwarf can no longer cope with the inflowing…

Space

Jul 12 2021

Lonely wanderers not uncommon

In my upcoming novel "Andromeda: The Encounter," an Earth-sized planet is wandering lonely through space. Planets far from any star - how common are they? Apparently, this is not an uncommon phenomenon. Star systems can become dynamically unstable and eject single planets. This could have happened to our solar system in early times. That it is a normal sight is also shown by a research work of British scientists. They have discovered evidence of a mysterious population of such free-floating planets. The findings were published in the Monthly Notices of the Royal Astronomical Society. The study, led by Iain…

Atomic nucleus swallows electrons: New supernova type found

Astrophysics

Jul 5 2021

Atomic nucleus swallows electrons: New supernova type found

At the end of its life, stars, if they are only heavy enough, perish in a gigantic firework, a supernova. Up to now, one knew roughly two ways to get there. A core-collapse supernova occurs when a massive star - one with more than 10 times the mass of the Sun - runs out of nuclear fuel and its iron core collapses, creating a black hole or neutron star. On the other hand, if a white dwarf - a low-mass star at the end of its lifetime - captures so much mass from a companion that it becomes unstable,…

Space

Jun 23 2021

Tectonic movements on Venus

Three missions will soon be visiting Venus. What is there to see there? Well, for example, something like tectonics, movements in the planet's crust. Mars and Earth's moon don't have anything like that. But Venus does, as a paper now states. "We have identified a previously unrecognized pattern of tectonic deformation on Venus that is driven by internal motions just as it is on Earth," says Paul Byrne, associate professor of planetary science at North Carolina State University and lead and co-lead author of the paper. "Although it's different from the tectonics we currently see on Earth, it's still evidence…

The birth of supermassive black holes from dark matter – and their growth

Astrophysics

Jun 17 2021

The birth of supermassive black holes from dark matter – and their growth

The universe is about 13.8 billion years old. In the beginning, there were no stars in it. But 600 to 800 million years later already mighty galaxies existed with gigantic black holes in their center, which are millions to billions times heavier than our sun. But where did these giants come from? For a long time it was assumed that they could have been formed by the collapse of gas clouds in protogalaxies. But the result is unsatisfactory. In this way, the black holes simply don't grow fast enough. A team led by a theoretical physicist at the University…

Space

Jun 14 2021

Mysterious shadow hides giant star

VVV-WIT-08 is a red giant star with 100 solar masses and 25,000 light years away from us. Ten years ago (25,010 years ago, of course) its brightness suddenly decreased drastically - down to one-thirtieth of its original value. There are indeed variable stars. In certain phases of life many types of stars show spontaneous changes. However, such a large decrease as in VVV-WIT-08 is rare. It speaks for the fact that the cause was not in the star itself, but in its environment. Did another object move in front of the star for a few hundred days and darken…

Life

Jun 10 2021

Surprising candidates for extraterrestrial life

When astronomers look for places outside Earth where life might exist, they often first check the habitable zone of star systems. After all, the Milky Way alone is home to 100 to 400 billion stars and at least that many planets. Habitable means that water should exist there in liquid form. Water, as far as we know, is the elixir of life. It has made life on Earth possible and is essential for the continuation of all living systems on the planet. This explains why scientists are constantly searching for evidence of water on other solid bodies in the…