Hard Science Fiction

Apr 14 2019

What dark matter is (not) made of

“When you have eliminated the impossible, whatever remains, however improbable, must be the truth,” the detective, Sherlock Holmes, says to Dr. Watson in “The Sign of the Four.” Cosmologists searching for dark matter, which should make up 85 percent of the universe’s mass, seem to be following a similar process right now. They are eliminating one component after another. Recently, they succeeded in eliminating two more possibilities. Dark matter is not made up of tiny black holes. This result was shown by astronomers with the help of the Japanese Subaru telescope. Their strategy was very interesting. According to theories…

The weather for HR 8799 e: 1000 degrees Celsius with clouds of iron and silicate dust

Astrophysics

Apr 9 2019

The weather for HR 8799 e: 1000 degrees Celsius with clouds of iron and silicate dust

HR 8799 e is a rather inhospitable place. The celestial body discovered in 2010 and orbiting the 30-million-year-young star HR 8799 at a distance of 129 light-years from Earth is a gas giant similar to Jupiter. But its host star shines nearly five times brighter than our Sun, creating a significantly hotter atmosphere for HR 8799’s innermost planet (despite the “e,” HR 8799 e is the closest planet to its host star) than Jupiter. That is quite astonishing because at approximately 14.5 AU, HR 8799 e is almost five times farther from its host star than Jupiter is from…

What does the interior of Neptune or Uranus look like?

Astrophysics

Apr 7 2019

What does the interior of Neptune or Uranus look like?

Exploring the interior of icy giant planets is not an easy task. Without more advanced technology, we won’t be able to use probes to make measurements on site, so researchers must rely on models. These models are based on what scientists know about the substances that make up these ice giants such as Neptune and Uranus. However, we can’t rule out that these models might contain errors. For example, it was previously assumed that carbon always took the form of diamond under very high pressures. Carbon and hydrogen are among the most abundant elements in the universe and make…

How to send a spaceship to the closest star using lasers

Proxima

Apr 5 2019

How to send a spaceship to the closest star using lasers

The StarShot program wants to accelerate mini-spaceships by means of laser bombardment to a velocity of one-quarter the speed of light so that they can reach our neighboring star, Proxima Centauri, within the foreseeable future. The technology sounds feasible, but still must overcome a few hurdles. Imagine you had to keep a ball floating in the air using a hairdryer. You will automatically think of a ping-pong ball floating a few inches above a fan. But could you accomplish this feat with a soccer ball located thirty feet above you? The hairdryer would have to be much larger and…

Mars

Apr 3 2019

Is it possible to fly on Mars?

Of course, it’s possible to fly to Mars – but how about on Mars? The red planet’s atmosphere is significantly thinner than Earth’s. Atmospheric pressure at Mars’s surface is 0.00636 bar, which is one-hundred-fiftieth of the pressure at Earth’s surface. For a heavier-than-air aircraft to take off, it needs lift. It’s difficult to generate enough lift in such a thin atmosphere – but engineers at NASA’s JPL have apparently done it. In any case, on NASA’s Mars 2020 rover mission, they want to include a small helicopter that could fly autonomously there at a height of up to five…

Astrophysics

Mar 20 2019

Physicists turn back time – a bit

“Man! If only I could turn back time!” According to an article in the science magazine Scientific Reports, physicists have apparently succeeded in doing just that – at least in the quantum realm and with very small particles. However, it’s still impossible to manipulate the wheel of time, because the Second Law of Thermodynamics distinguishes between the past and the future. Most other physical laws are reversible. But when the Second Law comes into play, nature behaves very stubbornly, and everything progresses in only one direction. The house of cards collapses, it doesn’t build itself. Without external influences, heat…

Astrophysics

Mar 17 2019

How to look inside a black hole

When mass is so strongly concentrated that not even light can escape its gravitational field, physicists call this phenomenon a black hole. In reality, however, the name doesn’t quite fit its true physical nature. This is because some radiation, so-called Hawking radiation, is indeed emitted from a black hole. In addition, black holes set their surroundings in so much turmoil that in no way do they remain invisible: the matter falling into the hole forms an accretion disk around it, there are all kinds of swirling, turbulent magnetic fields – there’s little reason to fear falling into a black…

Life

Mar 15 2019

Where are we most likely to find signs of extraterrestrial life?

Today, astronomers know that most stars develop a planetary system during the course of their life. It is estimated that the total number of planets exceeds the total number of stars. On average, each star has between one and two planets. With its 200 billion stars, the Milky Way therefore might have around 300 billion planets. Of course, there is a huge amount of variability in these planets. There are gas giants that rotate on very tight orbits and are almost as hot as their host star. There are icy planets on the distant outskirts of their systems, like…