Life

How many civilizations are there in the Milky Way? Life

How many civilizations are there in the Milky Way?

Are there other thinking creatures in the universe? Researchers recently determined that life should be at least relatively common. In terms of intelligence, however, the results, which were based on an analysis of its development on Earth, were less clear. A new article published in the Astrophysical Journal has come to somewhat more encouraging results. Astrophysicist Tom Westby, one of the authors, explains his group’s approach: “The classic method for estimating the number of intelligent civilizations relies on making guesses of values relating to life. Opinions about such matters, however, vary quite substantially. Our new study simplifies these assumptions using…
How common is life in the universe? Life

How common is life in the universe?

The question is basically unanswerable. The well-known Drake equation feigns a certain degree of precision but suffers from the fact that it is nearly impossible to reach agreement on values for any of its seven factors. Right now, we have only one example for intelligent life, and for us to draw conclusions for the entire universe from just our own existence would, indeed, be very human, but would be scientifically problematic. There is, however, an alternative. We could ask what the likelihood would be for life to develop on Earth if we turned back the clock and started over from…
Salty Mars puddles no place for life Life

Salty Mars puddles no place for life

On the surface of the Red Planet, normal bodies of water cannot exist for long periods of time under today’s conditions. It’s possible, however, that very salty “puddles” or reservoirs of liquid (“brines” in technical language) could remain stable on or just below the surface for some amount of time, especially during the Mars spring and summer months, when ice deposits thaw. Whether these puddles are suitable for life as we know it, however, remains questionable. In 2018, reports sparked headlines that these brines might have conditions that are friendly to life after all. One factor speaking for this…
Life in a hydrogen-rich atmosphere Astrophysics

Life in a hydrogen-rich atmosphere

The exoplanet K2-18b, about 124 light-years from Earth, is a kind of mini-Neptune, as astronomers discovered this past year. It is seven to ten times heavier than Earth and its radius is 2.7 times larger. K2-18b orbits its host star, a red dwarf, once every 33 days. Thus, it is located in its star’s habitable zone. For astronomers, however, it has one other special noteworthy feature: hydrogen, helium, and water vapor have been detected in its atmosphere. In the media, K2-18b has even been described as “Earth 2.0,” which it very definitively is not. The researchers who studied it…
Silent Sun: The phenomenon of our quiet star Astrophysics

Silent Sun: The phenomenon of our quiet star

The Sun is rather quiet. That’s the premise of my novel “Silent Sun.” But now researchers at the Max Planck Institute for Solar System Research (MPS) in Göttingen, Germany have also proved it with a systematic comparison published in Science. In such analyses, of course, it is important to make sure you are not comparing apples with oranges. Red dwarfs, for example, are considered much more active. But even among the class of yellow dwarfs like the Sun, there can be big differences. Therefore, the researchers selected candidate stars that were similar to the Sun in terms of important…
Kepler-1649c: an Earth twin with a short-tempered host star Astrophysics

Kepler-1649c: an Earth twin with a short-tempered host star

The Kepler telescope has already been shut down, but astronomers are still finding new exoplanets in its data. Kepler-1649c, which is 300 light-years from Earth, is one of these recently discovered treasures. The planet was overlooked by the first, automated search through the data. The rocky planet has one very intriguing characteristic: it is the most Earth-like exoplanet discovered to date. Kepler-1649c is only 1.06 times larger than Earth. Its host star supplies it with about three-quarters of the energy that the Earth receives from the Sun. That means that water, if it exists there, would be liquid on…
There’s life, even hundreds of meters below the ocean floor Life

There’s life, even hundreds of meters below the ocean floor

On Earth, there’s life everywhere – well, almost everywhere, one exception being the geothermal fields in the Ethiopian region of Dallol. Researchers have detected at least primitive bacteria almost everywhere: on the highest mountains, in hydrothermal vents, in corrosive lakes, and even deep in the oceans. Scientists have even found traces of life hundreds of meters below the bottom of the sea, as reported in an article in the magazine, Communications Biology. In their research, the scientists looked, in particular, at the Earth’s upper oceanic crust. It consists of basaltic lava, which has been deposited there from the depths…
Bad news for life on Titan – or not? Life

Bad news for life on Titan – or not?

So that life as we know it can emerge, it must be able to differentiate itself somehow from its environment. Therefore, every cell needs a shell that allows nutrients to pass through it from the outside, but nevertheless protects the cell’s insides from the outside world. On Earth, cell membranes perform this function and are made from lipids, hydrocarbon compounds that include, among other things, fatty acids. On Saturn’s moon, Titan, it is much too cold, at an average temperature of -180 °C, for the formation of lipids. But there is a different class of substances there that astrobiologists…