Brandon Q. Morris's Blog, page 20

Salty Mars puddles no place for life

On the surface of the Red Planet, normal bodies of water cannot exist for long periods of time under today’s conditions. It’s possible, however, that very salty “puddles” or reservoirs of liquid (“brines” in technical language) could remain stable on or just below the surface for some amount of time, especially during the Mars spring and summer months, when ice deposits thaw. Whether these puddles are suitable for life as we know it, however, remains questionable.

In 2018, reports sparked headli...

What the cloud layers above Saturn’s hexagon are made of

Jupiter has its Great Red Spot – Saturn, in contrast, has its enormous hexagon. For a long time, a six-sided structure with a diameter of 29,000 km (18,000 miles) has been rotating around Saturn’s north pole. Thus, the hexagon is considerably larger than Jupiter’s spot, which is only 16,000 km (10,000 miles) across and more than twice as large as the whole Earth. The hexagon was first discovered in 1981 by Voyager 1 (photographed in infrared in the image below).

Starting in 2006, the Cassini pro...

Life in a hydrogen-rich atmosphere

The exoplanet K2-18b, about 124 light-years from Earth, is a kind of mini-Neptune, as astronomers discovered this past year. It is seven to ten times heavier than Earth and its radius is 2.7 times larger. K2-18b orbits its host star, a red dwarf, once every 33 days. Thus, it is located in its stars habitable zone.

For astronomers, however, it has one other special noteworthy feature: hydrogen, helium, and water vapor have been detected in its atmosphere. In the media, K2-18b has even been...

Silent Sun: The phenomenon of our quiet star

The Sun is rather quiet. Thats the premise of my novel Silent Sun. But now researchers at the Max Planck Institute for Solar System Research (MPS) in Göttingen, Germany have also proved it with a systematic comparison published in Science. In such analyses, of course, it is important to make sure you are not comparing apples with oranges. Red dwarfs, for example, are considered much more active. But even among the class of yellow dwarfs like the Sun, there can be big differences.

Therefore,...

Pulsars: of black widows and redback spiders

Double-star systems end like many marriages: one of the partners almost always dies before the other. When a star dies, if it was not too large, all that remains is a neutron star. This contains a big portion of the mass of the original star, but has a diameter of only about 20 kilometers (12.4 miles). So, like a figure skater who pulls in her arms to spin faster, the neutron star must rotate very quickly about its axis. In doing so, it emits radio waves like a lighthouse for astronomers it...

How monster galaxies feed off of their neighbors

In very large, ancient galaxies, usually more than ten billion light-years away from us, many stars behave differently than in the Milky Way, where the large majority of stars obediently follow the motion of arms rotating about the center of the galaxy. Why is that? It seems galaxies have something in common with people: when theres too much substance around their mid-sections, its usually a result of too much eating. Giant galaxies have swallowed up too many of their neighbors, one after the...

Blown to dust: the first exoplanet visible in a telescope is no more

In 2008, researchers looking at images from the Hubble Space Telescope found a bright spot moving around the star Fomalhaut located 25 light-years from Earth. At 400 million years old, Fomalhaut is still relatively young. The star, twice as heavy as the Sun and 17 times brighter, is also circled by a dust disk that the researchers identified as a remnant from planetary formation.

Fomalhaut b was thus the first exoplanet detected through direct, optical imaging, not just indirectly through...

Searching for the super supernova

A supernova is a powerful explosion at the end of the life of many stars. All massive stars with an initial mass greater than eight solar masses will eventually be torn apart by a supernova, but that fate also awaits smaller stars that are unlucky enough, after their actual end as a white dwarf, to accrete more material from a partner star, with which they form a binary system. Without supernovae, there would be no life, because its the only way heavy elements can be spread around the cosmos....

Einstein was right – and Sagittarius A* is a giant black hole

Physical theories have one downside that physicists are very aware of: they cannot be proven true for always. Instead, they can be considered correct just until someone can demonstrate that theyre wrong. That applies to Einsteins theories too. His General Theory of Relativity, however, has been amazingly robust so far. Einstein himself proposed three tests for his revolutionary theory, which wasnt based on experimental findings, but on an almost philosophical line of thinking.

His first test...

Kepler-1649c: an Earth twin with a short-tempered host star

The Kepler telescope has already been shut down, but astronomers are still finding new exoplanets in its data. Kepler-1649c, which is 300 light-years from Earth, is one of these recently discovered treasures. The planet was overlooked by the first, automated search through the data. The rocky planet has one very intriguing characteristic: it is the most Earth-like exoplanet discovered to date.

Kepler-1649c is only 1.06 times larger than Earth. Its host star supplies it with about...