Life

Signs of life from the clouds of Venus? Life

Signs of life from the clouds of Venus?

Our hot sister planet, Venus, basically has no potential for life on its surface – the pressure and temperature are much too high. Nevertheless, in “The Clouds of Venus,” a team from NASA made an interesting discovery. I was reminded of this when I read a new press release from Cardiff University. Astronomer Jane Greaves and her colleagues have been analyzing Venus’s atmosphere for years and stumbled across an interesting substance: phosphane (older, but chemically incorrect name: phosphine). On Earth, phosphane, a compound of phosphorus and hydrogen (PH3), is a gas produced predominantly by anaerobic biological sources. The conditions on…
Panspermia: colonies of bacteria can survive in interplanetary space Life

Panspermia: colonies of bacteria can survive in interplanetary space

Deinococcus radiodurans is one tough bacterium. Neither the detonation of atom bombs nor the terrors of empty space bother it. But could it travel from planet to planet as a stowaway? Imagine microscopically small lifeforms being transported through space and landing on another planet. Bacteria that find suitable conditions for their survival on the new planet could then multiply and spawn life on the other side of the universe. This theory, which is known as “panspermia,” postulates that microbes could travel between planets and spread life throughout the universe. Panspermia has been debated for a long time, because it obviously…
How many planets fit into a star’s habitable zone? Life

How many planets fit into a star’s habitable zone?

The habitable zone of our Solar System is relatively narrow. Mars is at the very outer edge of it, while Venus, which orbits closer to the Sun than Earth, is not quite inside it. Of eight planets, only the Earth is at just the right distance from its host star. A ratio like this would naturally lower the chances of finding inhabitable worlds in the universe. But is the Solar System an exception or the rule? Astronomers have, in fact, found other star systems that give a rosier outlook. For instance, three planets are in the habitable zone of…
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…