Life | Pagina 9 | Hard Science Fiction

Ott 15 2018

When can we be certain that we’re the only civilization in the galaxy?

Are we alone in the universe? Most science-fiction authors would answer that question with a no. Scientists, however, aren’t so sure. SETI projects, such as Breakthrough Listen, have not produced any clear results, at least not yet. But assume we search and search and search – and find nothing. Will there come a moment when we can say with some certainty that we are alone in the universe – and can stop searching? Yes, says Claudio Grimaldi from the École Polytechnique Fédérale de Lausanne (Swiss Federal Institute of Technology Lausanne; EPFL). In a paper in PNAS, he calculated when…

Terraforming Mars: There’s not enough carbon dioxide

Life

Ago 2 2018

Terraforming Mars: There’s not enough carbon dioxide

The atmosphere of the red planet not only lacks enough oxygen, it is also very thin. Instead of a surface pressure of one bar on Earth, the surface pressure in Mars’s atmosphere reaches only 6 millibars, thus, less than one-hundredth of the Earth’s surface pressure. Consequently, to work on Mars, astronauts would have to wear pressurized suits. The atmosphere would have to be considerably denser for a respiratory mask to be sufficient. If the density were even higher, carbon dioxide, the main component of Mars’s atmosphere, could play its same role that is so dreaded on Earth, that of…

Life

Giu 17 2018

Life on distant moons?

In the search for Earth’s siblings, astronomers often focus on rocky planets, and for good reason: in our Solar System, planets similar to Earth are located only in the habitable zone. But this does not have to be the case in other solar systems. There, gas giants as big as Jupiter or even bigger could be located in the habitable zone of their host star. The habitable zone might even be larger in these systems, because these giant planets could also provide energy to the moons in their orbit. (altro…)

Organic matter on Mars – and a seasonal methane cycle

Life

Giu 7 2018

Organic matter on Mars – and a seasonal methane cycle

Researchers estimate that every year, 100 to 300 tons of organic matter from space must land on the Mars surface. If one considers that this process has been going on for billions of years, then there must be abundant organic deposits (which, to be clear, were produced from abiotic processes and thus have nothing to do with organic life) to be found on Mars. However, the first probes, which analyzed Mars’s soil with a gas chromatography, Viking-1 and Viking-2, found absolutely no traces of organic materials in the regolith samples that they analyzed. This was a source of astonishment…

Book now: NASA opens a travel bureau for exoplanets

Life

Mag 31 2018

Book now: NASA opens a travel bureau for exoplanets

NASA had a great idea there: At the "Exoplanet Travel Bureau" you can now book – fictious – trips to different exotic destinations in space. You have the choice between Trappist-1d (or 1e, NASA isn’t sure), Kepler-16b, Kepler-186f, and more. The program then beams you to the surface of the planet, where you can look around by clicking your mouse and learn about some of the sights. Of course the views are (for now) only from an artist’s imagination. (altro…)

Life

Apr 29 2018

Did life come from outer space?

How did the building blocks of life come about on Earth? So far, science has not given a very exact answer to this question. The most important experiment on this question was conducted in 1952 by Stanley Miller and Harold Urey at the University of Chicago. They mixed together simple chemical substances of a hypothetical young Earth atmosphere – water, methane, ammonia, hydrogen, and carbon monoxide, but no oxygen – and exposed this mixture to electrical discharges that were meant to replicate the energy supplied from lightning in thunderstorms. The result: after some time, organic molecules were produced. At…