Hard Science Fiction

Apr 2 2022

4 mile high ice volcanoes on Pluto

The exploration of the dwarf planet Pluto is divided into two eras: Before the arrival of NASA's New Horizons probe, the celestial body was thought to be an icy, unspectacular Kuiper Belt object. But New Horizons then delivered images and data that sent astronomers into raptures. The composition of Pluto's surface shows that there are a variety of ages here, from relatively old, heavily cratered regions to very young surfaces with few to no impact craters. One of the regions with very few impact craters is dominated by huge mountains with humpbacked flanks not found anywhere else in the…

Peas, blueberries and grapes – not every galaxy is like the Milky Way

Space

Apr 1 2022

Peas, blueberries and grapes – not every galaxy is like the Milky Way

Elliptical galaxies, spiral galaxies, barred spiral galaxies, you've probably heard of them. But did you know that there are types of galaxies named after green peas, blueberries, or purple grapes? When a group of amateurs within the "Galaxy Zoo," a project conducted by citizen scientists, classified galaxies observed by the Sloan Digital Sky Survey (SDSS) by color and morphology, they found 251 very special galaxies that didn't easily fit into the known galaxy types. These galaxies, which looked round and dense like beans and appeared green on digital images, were later named "Green Pea Galaxies." (more…)

Space

Mar 30 2022

Earendel: The farthest star

Far-away stars, however luminous, cannot be photographed individually even with the best space-based telescopes. But this would be extremely interesting for researchers, because with increasing distance we are entering the early days of the universe, about which we still know too little. But with a bit of luck, the universe itself is helping astronomers - by placing powerful galaxies in such a convenient way that they amplify the light of a star that is actually much too distant - in this case in the form of the galaxy cluster WHL0137-08. For example, the Hubble Space Telescope recently succeeded in…

Space

Mar 23 2022

How old is the Milky Way?

Our home galaxy contains up to 400 billion stars, and to cross it would take 200,000 years even at the speed of light. Such a huge object (which is rather average in cosmic comparison) does not come into being overnight. The Milky Way was actually born relatively early - at a time when the universe was still quite young. But when exactly, and how do you measure that? Quite simply, if you want to know how old a forest is, you determine the age of its trees. The stars of the Milky Way do not have annual rings, but…

Astrophysics

Mar 19 2022

When the universe began to boil

How did the supermassive black holes come into being, which today are gigantic sentinels in the center of many galaxies? Initially, one proceeded from the obvious: The giants grew by accreting other matter or consuming black holes, that is, by merging with them. Step by step, from small to medium to giant. But this concept has a couple of problems. First, we have not yet been able to detect the necessary intermediate stages. They should still exist, but so far we have only found small black holes - or the really big ones. Problem number 2 is that there…

Even on smaller icy moons, the chances for life on the ocean floor are good

Enceladus

Mar 3 2022

Even on smaller icy moons, the chances for life on the ocean floor are good

The fact that astrobiologists have such high hopes for icy moons like Enceladus or Europa is not only due to the oceans they have been able to detect under their ice crusts, but also to the fact that they are geologically active worlds. The culprits are the giant parent planets Saturn and Jupiter, respectively, which really knead the moons with their gravitational force. This creates heat, which keeps the water in their hidden oceans liquid and relatively warm. The water in turn dissolves from the underlying rock layers what potential life could need. Energy is also released in the…

How do you weigh a particle that you don’t even know exists?

Astrophysics

Feb 27 2022

How do you weigh a particle that you don’t even know exists?

Dark matter accounts for 85 percent of the mass content of the universe. Researchers call it "dark" because we don't notice anything about it - except for its gravity. However, it can be detected quite well. Without dark matter, galaxies would move differently than they demonstrably do, and the universe would have a different structure. The physicists need the Dumkle materie thus, in order to explain the cosmos. Too bad that they still do not know what it consists of. There are candidates for it: MACHOs (massive compact halo objects), for example, WIMPs (weakly interacting massive particles) and even invisible…

Shrouded in ash: New type of star discovered

Space

Feb 20 2022

Shrouded in ash: New type of star discovered

Most stars follow the main sequence of the Hertzsprung-Russell diagram in their life cycle. This is because they fuse certain elements in each part of their life, starting with hydrogen, followed by helium. Only particularly large or small stars deviate from this, or binaries that, for example, get fresh material from their neighbors despite their small size. But there are deviations from the rule, and lots of them. A team of German astronomers led by Klaus Werner of the University of Tübingen has discovered another exception. To do so, the researchers took a closer look at the light from white…