Life | Hard Science Fiction

Sep 24 2022

Conditions for life in the Enceladus ocean increasingly certain

Saturn's moon plays a special role in my books. Therefore, I am always very happy when there is news about possible life in the moon's ice ocean. Like the following. A team of scientists has apparently discovered new evidence for an important building block for life in the subsurface ocean of Saturn's moon Enceladus. Their model calculations suggest that Enceladus' ocean should be relatively rich in dissolved phosphorus, an essential ingredient for life. "Enceladus is one of the most important targets in humanity's search for life in our solar system," said Dr. Christopher Glein of Southwest Research Institute, a…

Life

Jul 29 2022

What saved Earth from the fate of Mars?

Three billion years ago, liquid water existed on Mars as well as on Earth. Today, this is only the case on our home planet. Why is that? Mars no longer has such a strong magnetic field as the Earth. Therefore the solar wind can take the atmosphere better there than here. The magnetic field is generated in the outer core of the Earth, where liquid iron rotates (this is called a "geodynamo"). About 565 million years ago, however, the strength of the magnetic field decreased to 10 percent of its present strength. Then the field mysteriously recovered and regained strength…

Life

Jul 11 2022

News from the cosmic origin of life

Nitriles, a class of organic molecules with a cyano group, i.e. a carbon atom bonded to a nitrogen atom via an unsaturated triple bond, are usually toxic. Yet, paradoxically, they are also an important precursor for molecules that are essential for life - namely, ribonucleic acid (RNA). Astrobiologists already knew that complex molecules are surprisingly common even in space, which is hostile to life. Now, a team of researchers from Spain, Japan, Chile, Italy and the United States has shown that a wide range of nitriles occur in interstellar space in the molecular cloud G+0.693-0.027, near the center of…

Life

Jun 28 2022

Worlds quite different from Earth could also harbor life

Are our ideas of the habitable zones around a star too Earth-centric? Of course. We've only found one example of life in the universe so far, so we all draw conclusions. But there are alternatives, as researchers from the University of Bern and the University of Zurich have just reported in a study published in the journal Nature Astronomy. According to the study, favorable conditions could even prevail for billions of years on planets that barely resemble our home planet. "One of the reasons water can be liquid on Earth is its atmosphere," explained study co-author Ravit Helled, professor…

Life

May 4 2022

More life on younger planets

Nowadays we know more than 5000 exoplanets. Among them are some that are similar in size to Earth, are also made of rock, and orbit their star in an area that astrobiologists call the habitable zone. Habitable here refers to life as we know it, which is based on water and carbon and therefore also requires liquid water on the surface. Which of these candidates should we look at first, for example with the new James Webb telescope, which will also be able to determine the atmospheric composition of distant worlds? Where are the chances of finding life the…

Jupiter’s moon Europa could have water near surface

Enceladus

Apr 19 2022

Jupiter’s moon Europa could have water near surface

Jupiter's moon Europa, like Saturn's moon Enceladus, is an important target for the search for extraterrestrial life. That a liquid, salty ocean exists beneath its ice crust seems clear since the visits of Voyager and Galileo. But to explore this body of water, visitors must first drill through at least 20 to 30 kilometers of ice. Or maybe not? At least that's what a new study based on data from the Greenland Ice Sheet, published in Nature Communications, suggests. The results could provide insights into the geophysical processes that led to the formation of Jupiter's moon. Riley Culberg, a…

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…

Life

Feb 13 2022

A planet that has outlived its star

Located 117 light-years from Earth, the star WD1054-226 is a white dwarf - the remnant of a star the size of our Sun that has reached the end of its life. It's about the size of Earth, but about as heavy as the Sun. And it's hot: 20,000 to 30,000 Kelvin on the surface, 20 million Kelvin inside. Fusion processes no longer take place, but it takes about 10 billion years for it to cool down completely - our sun has only been around for five billion years. During this time, of course, a habitable zone can form around…