Life | Hard Science Fiction

Apr 19 2023

More life at the first stars?

The very first stars consisted only of hydrogen and helium - there were no other elements in the still young cosmos. When they died in gigantic explosions, they released what had accumulated in them: heavier elements, which were needed so that planets could form. The more heavy elements (cosmologists call them "metals," although chemically they aren't necessarily), the more planets can form, the better chance life has, right? Not quite. Whether life has a chance depends on more than just the composition of a celestial body. In fact, planets located in the habitable zones of metal-poor stars may be…

Life

Feb 21 2023

Life on Mars? We will not find it this way

The scientific instruments currently being used on Mars may not be sensitive enough to detect possible traces of life in this environment. Researchers explain this in a paper published in Nature Communications. Since the Viking missions in the 1970s, there have been several attempts to search for signs of life on Mars. Now, half a century later, even the latest sophisticated instruments on NASA's Curiosity and Perseverance rovers have detected only small amounts of simple organic molecules. Why aren't we making faster progress? It could be because of the nature of the substances in the Martian rocks - or…

Enceladus

Feb 18 2023

How life could be detected on Enceladus

The mystery of whether microbial alien life exists on Enceladus could be solved by a spacecraft orbiting Saturn's moon, according to a new study led by University of Arizona researchers. In a paper published in The Planetary Science Journal, the researchers show how a hypothetical space mission could provide definitive answers. When Enceladus was first surveyed by NASA's Voyager 1 spacecraft in 1980, it looked like a small, unexciting "snowball" in the sky. Later, between 2005 and 2017, NASA's Cassini spacecraft orbited the Saturn system, examining Saturn's complex rings and moons in unprecedented detail. Scientists were stunned when Cassini…

Why Venus died the heat death – and the Earth did not

Life

Nov 23 2022

Why Venus died the heat death – and the Earth did not

Venus, Earth's hot little sister, was probably once habitable, too, a long time ago. It basically orbits in the habitable zone. Surface temperatures of 450 degrees would actually not be expected there, were it not for the dense CO2 atmosphere that heats up the planet with its greenhouse effect. But why did this happen on Venus - and not on Earth so far? Volcanism is probably to blame, as researchers show in a new paper. According to the paper, volcanic activity that lasted hundreds to thousands of centuries and ejected massive amounts of material may have helped transform Venus…

Enceladus

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…