Hard Science Fiction

Oct 1 2020

Fresh frozen items delivered to Enceladus’s north pole too

No, unfortunately nobody’s opened a new Ben and Jerry’s on Saturn’s icy moon Enceladus. Not yet, at least. But a new paper just published in the magazine, Icarus, shows again just how valuable the images are from the joint NASA-ESA mission Cassini, even years after the probe was intentionally crashed into Saturn. Specifically, Cassini also delivered the most detailed global infrared images ever taken of Saturn’s moon Enceladus. Combined with photos of Cassini’s other cameras, they provide convincing evidence that the northern hemisphere of the moon is covered with relatively fresh ice from its interior. The scientists that were part of…

Astrophysics

Sep 28 2020

The giant and the dwarf

Size alone is not always the most important factor. Sometimes, large things also orbit small things – because the details of a system matter. Astronomers have now found a real example for this situation in space, about 80 light-years from us, using the TESS telescope. The discovery published in Nature shows the likely presence of a planet the size of Jupiter orbiting the white dwarf, WD 1856+534, once every 34 hours. “This planet is roughly the size of Jupiter, but it also has a very short orbital period – one year on this planet is only 1.4 days long, so…

Astrophysics

Sep 27 2020

How the Magellanic Stream was formed

The Milky Way does not travel through the universe alone. It is accompanied on its journey by smaller galaxies. The two largest are the Small Magellanic Cloud and the Large Magellanic Cloud, which are both visible as dusty twin smudges in the southern hemisphere. When the Magellanic Clouds started orbiting the Milky Way billions of years ago (astronomers are not certain about the timing and the gravitational bond, it’s possible that they are still on their first approach to the Milky Way), an enormous stream of gas known as the Magellanic Stream was ripped out of them. The stream…

Deformed disk around the triple star system GW Orionis

Space

Sep 26 2020

Deformed disk around the triple star system GW Orionis

Our Solar System is remarkably flat, because all the planets orbit in the same plane. But that’s not always the case, especially not for planet-forming disks around systems made up of multiple stars. GW Orionis, for example, which is located more than 1300 light-years away in the constellation Orion, has three stars and a deformed, broken-apart disk surrounding these stars. “Our images show an extreme case where the disk is not flat at all, but is deformed and has a slanted ring that has detached from the disk,” says Stefan Kraus, professor for astrophysics at the University of Exeter,…

Is dark energy hidden in the husks of burned-out stars?

Astrophysics

Sep 25 2020

Is dark energy hidden in the husks of burned-out stars?

The idea that the expansion of the universe is accelerating is taken as fact today. The cause is a repulsive form of energy, dark energy. But its nature remains a mystery. Now, a team of researchers at the University of Hawai’i in Mānoa have made an interesting prediction in The Astrophysical Journal: dark energy, which is responsible for this accelerated growth, could originate from a giant sea of compact objects spread out in the cavities between galaxies. Since the mid-1960s, physicists have known that the collapse of stars might not produce true black holes, but instead so-called “GEneric Objects…

Life

Sep 25 2020

Signs of life from the clouds of Venus?

Our hot sister planet, Venus, basically has no potential for life on its surface – the pressure and temperature are much too high. Nevertheless, in “The Clouds of Venus,” a team from NASA made an interesting discovery. I was reminded of this when I read a new press release from Cardiff University. Astronomer Jane Greaves and her colleagues have been analyzing Venus’s atmosphere for years and stumbled across an interesting substance: phosphane (older, but chemically incorrect name: phosphine). On Earth, phosphane, a compound of phosphorus and hydrogen (PH3), is a gas produced predominantly by anaerobic biological sources. The conditions on…

Panspermia: colonies of bacteria can survive in interplanetary space

Life

Sep 11 2020

Panspermia: colonies of bacteria can survive in interplanetary space

Deinococcus radiodurans is one tough bacterium. Neither the detonation of atom bombs nor the terrors of empty space bother it. But could it travel from planet to planet as a stowaway? Imagine microscopically small lifeforms being transported through space and landing on another planet. Bacteria that find suitable conditions for their survival on the new planet could then multiply and spawn life on the other side of the universe. This theory, which is known as “panspermia,” postulates that microbes could travel between planets and spread life throughout the universe. Panspermia has been debated for a long time, because it obviously…

Milky Way vs. Andromeda: the collision has already begun

Astrophysics

Sep 10 2020

Milky Way vs. Andromeda: the collision has already begun

It’s inevitable that the Milky Way and the Andromeda Galaxy will one day collide and merge, even though right now there’s still 2.5 million light-years between them. Thus, the light that we see from Andromeda today was emitted from there 2.5 million years ago. The two most massive members of the Local Group are approaching each other at 120 kilometers per second. In three to four billion years (so while our Sun is still alive), up to 1.3 billion stars of the two galaxies will encounter each other. After another maybe three billion years, the merger will produce a…