Life | Hard Science Fiction

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…

Life

Feb 7 2022

Did a deadly poison lead to life on earth?

Compounds between carbon and nitrogen are called cyanides. The carbon atom is triple-bonded to the nitrogen atom. It therefore has one valence left to become hydrocyanic acid with hydrogen, for example, or potassium cyanide ("cyanide") with potassium. These are usually highly toxic. however, there are more complex molecules in which the cyanide is so tightly bound that it is no longer toxic. For example, the additive E536 (potassium hexacyanidoferrate(II)) is approved as a food additive. Cyanides could also have prepared the way for the emergence of life in the early days of the Earth, four billion years ago. This…

Mimas has an ocean under the surface too

Enceladus

Jan 20 2022

Mimas has an ocean under the surface too

Saturn's moons Enceladus and Titan have one, as do Jupiter's moons Ganymede, Callisto and Europa and the dwarf planet Pluto: a liquid ocean beneath their icy surfaces. Perhaps the same is true of Saturn's moon Mimas, as a Southwest Research Institute scientist suspects. Dr. Alyssa Rhoden, a specialist in the geophysics of icy satellites, actually set out to prove that Saturn's tiny, innermost moon is a frozen, inert satellite. Instead, she found evidence that the moon also has a liquid inner ocean. One of the most fundamental discoveries of the past 25 years in planetary science is that worlds…

Life

Jan 16 2022

Earth cools faster

Earth is hot: up to 3500 degrees Celsius (6300 °F) in the mantle, 5000 degrees Celsius (9000 °F) in the outer core and 6000 °C (10,800 °F) in the (solid) inner core. This brings us some advantages. Not only us, but all life on Earth. There is, for example, the magnetic field, which is fueled by iron currents in the outer core and protects us from cosmic radiation. But also plate tectonics, which not only gives us mountains, volcanoes and earthquakes, but has also favored the emergence of complex life forms. If it stops at some point, erosion will…