Hard Science Fiction

Oct 10 2021

Planets on a collision course

The binary star system XZ Tauri, 450 light-years from Earth, could be an interesting sight in a few billion years. As researchers have discovered with the help of the Atacama Large Millimeter/submillimeter Array (ALMA), the protoplanetary disks of the two stars are perpendicular to each other, see animation. The first planets are apparently being formed in these disks, which consist of gas and dust. When this process is complete, it should have a fascinating (but possibly dangerous) effect for the system's inhabitants: Again and again, planets belonging to another star approach and move away again - depending on the…

Mars

Oct 5 2021

Massive floods on Mars

Today, it's pretty dry on the Red Planet. But that wasn't always the case - quite the opposite, as researchers at the University of Texas at Austin can see from the way rivers and lakes have changed. On Earth, erosion by rivers is usually a slow process. On Mars, however, massive floods from overflowing crater lakes played a preeminent role in shaping the Martian surface, scouring out deep chasms and moving huge amounts of sediment. The study, published Sept. 29 in the journal Nature, shows that the floods, which likely lasted only a few weeks, removed more than enough…

Astrophysics

Sep 23 2021

A planet at maximum fluffiness

It's not often that the word "fluffy" appears in a press release about a new astronomical discovery. It refers to the exoplanet WASP-127b, which orbits a star a good 500 light-years from Earth that is slightly larger than the Sun. An international team of astronomers has now not only detected clouds there, but also measured their height with unprecedented precision. WASP-127b is a so-called "hot Saturn" - a giant planet with a similar mass to Saturn, but unlike our (cold) Saturn, it orbits very close to its sun. During one orbit around its star, WASP-127b therefore receives 600 times more radiation…

Astrophysics

Sep 22 2021

A huge hole in space

About 500 to 1000 light-years from Earth, two large masses of cold cosmic matter are concentrated in space. "Cold" because they are matter in molecular form. The Perseus and Taurus molecular clouds each contain so much mass that at least 10,000 suns could form from them. Nevertheless, they are almost invisible in their entire extent, because they do not glow. The situation is different in the infrared. Heat radiation arises here, because an area concentrates more and more and gives birth to new stars. Between these two clouds, however, there is no normal interstellar matter. Rather, astronomers have now…

Mars

Sep 15 2021

Mars structures from blood and urine

When establishing colonies on Mars or the Moon, it will hardly be possible to bring the necessary building material from Earth. Transporting even a single brick to Mars could initially cost up to two million dollars. The solution is to use resources found on the ground - sand and dust that can be combined with water to make a building material. But ordinary water still won't do. Additional binders are needed. In the future, these could be produced by the crew itself - in the form of blood and urine. The human body is a pretty good bioreactor. We…

Let there be light: How to generate photons from nothing

Astrophysics

Sep 10 2021

Let there be light: How to generate photons from nothing

From black holes we know the effect of Hawking radiation: If in vacuum a pair of photons is born in a random way and one of them falls into the black hole, the other one remains: light from nothing. The energy debt to the universe must be paid by the black hole, which is why it evaporates over many billions of years. But there is a second trick. With the black hole the gravity plays the role of the magician who makes the one photon disappear. But according to the equivalence principle of the general relativity, the wizard can…

There are fewer boulders lying around on Mercury than on Moon

Space

Aug 22 2021

There are fewer boulders lying around on Mercury than on Moon

Mercury can very well be imagined as an extreme version of the Earth's moon. The rocky planet orbits so close to the sun that it is exposed to much stronger temperature fluctuations than the moon. Water, like on the Moon, exists only in the few areas that are never exposed to sunlight. Nevertheless, as NASA's Messenger probe photos have shown, there are a few characteristic differences at the surface. For example, there are far fewer boulders lying around on Mercury. Why is that? An international group of planetary scientists has now analyzed this for the first time and described…

Superflares may not be that dangerous for planets

Life

Aug 20 2021

Superflares may not be that dangerous for planets

In "Proxima Rising," the planet Proxima b and its inhabitants become victims of an eruption of the central red dwarf, a superflares. Astronomers have long suspected that such radiation bursts can permanently damage the atmospheres - and thus the habitability - of exoplanets. A new study published Aug. 5 in the Monthly Notices of the Royal Astronomical Society may now give the all-clear. Using optical observations from the Transiting Exoplanet Survey Satellite - TESS for short - the team, led by astronomers from the Leibniz Institute for Astrophysics Potsdam, studied large superflares on red dwarfs, a class of young, small…