Space

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

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…
How to send a spaceship to the closest star using lasers Proxima

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

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…
How heavy is the Milky Way? Space

How heavy is the Milky Way?

How much does our home galaxy, the Milky Way, weigh? It’s not a very easy task to determine the true dimensions of an object when you live inside that object. Imagine trying to measure the size of your house while sitting at the kitchen table. On top of that, a large part of its mass is not even visible, because it’s dark matter. Scientists estimate there are about 100 to 300 billion stars in the Milky Way. That gives a visible mass of approximately 900 billion Suns at a diameter of 170,000 to 200,000 light-years. But the visible mass…
4000 stars: there’s a river of stars flowing through the Sun’s neighborhood Space

4000 stars: there’s a river of stars flowing through the Sun’s neighborhood

And from the cluster sprang forth a river: that’s not an attempt to be lyrical, just cosmic reality. When stars are born in a star cluster, they often only spend their youth in this group. As time goes on, the entire star cluster starts to feel the effects of gravitational forces from nearby galaxies. Like all stars of the galaxy, the cluster is flung around its core, deforming it over time, with the cluster becoming longer and longer and finally forming a stellar stream – a group of stars traipsing together through the galaxy. (more…)
Where is the universe hiding its missing mass? Space

Where is the universe hiding its missing mass?

Black makes a person look thin, people like to say. The universe apparently knows this trick too. In any case, it looks significantly skinnier to astronomers than they think it is in reality. Scientists think this because they can calculate how much matter was originally released by the big bang (this refers only to normal matter, not dark matter). If we add up everything that we can see in the sky today, however, we only get to two-thirds of this original amount. Where is the universe hiding the other third? This “Missing Baryon Problem” is an important question, because…
The universe in your living room: Sega Toys Homestar Flux Space

The universe in your living room: Sega Toys Homestar Flux

How does a science fiction writer best prepare for work? By looking into the universe, of course! Right now, however, it’s not very cozy outside at night, when the curtain has been raised for the universe’s spectacular show, so I bought myself the less-than 200 dollar home planetarium Homestar Flux. The device comes in well-designed packaging. In addition to the projector, you also receive a USB power cord (handy, because then you can also operate the projector from portable power banks), a small manual, and two “Star Discs.” They look similar to Mini-DVDs, but they are actually thin plastic…
Dark energy changes over time Space

Dark energy changes over time

Dark energy is thought to be the reason why the universe continues to expand faster and faster, instead of contracting. Yet researchers still don’t have a well-founded theory on what exactly this mysterious form of energy is. If current theories of the universe are correct, dark energy must account for up to 72 percent of the total matter of the universe today. But what about in the past? Current theory assumes that dark energy had little influence early on. So, the expansion of the universe must have changed significantly over time. Now, with the help of NASA’s Chandra X-ray…