Brandon Q. Morris's Blog, page 19

How a steam-powered robot could explore Enceladus

The thing designated SPARROW that engineers from NASA’s Jet Propulsion Laboratory want to send to the icy moons of Enceladus and Europa has nothing at all in common with its namesake bird. Americans and scientists love acronyms, and the designation SPARROW came from the name “Steam Propelled Autonomous Retrieval Robot for Ocean Worlds.” The project is part of the “NASA Innovative Advanced Concepts” program (NIAC), whose current candidates were announced by NASA earlier in Spring 2020.

SPARROW st...

Too heavy to be a neutron star, too light to be a black hole

Sometimes (always?), new research instruments like the Ligo-Virgo gravitational wave detector collaboration not only provide long expected answers to old questions, but also create completely new questions too. Take, for example, GW190412, which is the designation given to the latest conundrum, for which physicists can thank Ligo-Virgo. It refers to a gravitational wave burst that reached Earth on 14 August 2019. From the measured data, the researchers determined that a relatively lightweight ob...

How many civilizations are there in the Milky Way?

Are there other thinking creatures in the universe? Researchers recently determined that life should be at least relatively common. In terms of intelligence, however, the results, which were based on an analysis of its development on Earth, were less clear.

A new article published in the Astrophysical Journal has come to somewhat more encouraging results. Astrophysicist Tom Westby, one of the authors, explains his group’s approach: “The classic method for estimating the number of intelligent civ...

Sunspot problems in older stars

Sunspots caused by magnetic fields have plagued our Sun for ages. Their frequency changes approximately every eleven years, but even in the worst case they never cover more than 0.4 percent of the Sun’s surface. However, the Sun is pretty big, which you can appreciate from the fact that a sunspot can be about as large as a whole cross section of the Earth.

On a cosmic scale, however, our Sun is only a small light and, just like there are people with more or less freckles, there are also stars th...

Where are the very first stars hiding?

Stars like the Sun are made largely from waste – leftover matter ejected billions of years ago during the death of previous star generations. We know this is the case from their content of heavy elements, their metallicity. When the universe was still young, there was only hydrogen, helium, and a little lithium, nothing else. These elements formed the very first stars a long, long time ago. The first stars are called “Population III” stars, while the current generation, which also includes the S...

Giant stars prevent the formation of planets

The chance for a young star to raise some planetary offspring apparently depends a great deal on the neighborhood it lives in. This, at least, is one finding that astronomers have discovered with the help of the Hubble Space Telescope. For three years, they observed the open star cluster Westerlund 2 which contains about 5,000 stars, including some real giants, within a relatively small space.

Westerlund 2 is only one to two million years old. That makes it an ideal candidate to test theories on...

What a rare ring galaxy reveals about cosmic history

Ring galaxies like the well-known Cartwheel Galaxy can form for two reasons:

First – a spiral galaxy is involved in a collision with another galaxy, which punches through the spiral galaxy, thereby clearing away its center.
Second – the bar of a barred spiral galaxy becomes unstable because its rotational velocity becomes too high.

Events like these are rare, so ring galaxies themselves are also rare.

All the more reason for astronomers to celebrate, because with R5519, they have now found an...

2019 LD2: the unruly comet

Asteroids and comets are generally thought to be different classes of celestial objects. But is the strict distinction really justified? The interstellar visitor ʻOumuamua, for example, was initially thought to be a comet, but didn’t develop either a coma or a tail and was then classified as an asteroid. In the meantime, its trajectory has been calculated so precisely that it must have lost mass – which means it is definitely a comet.

The object 2019 LD2 discovered by the Asteroid Terrestrial-im...

How a planet grows up

AB Aurigae, 520 light-years from Earth in the constellation, Auriga (the charioteer), is far from grown up: the star is a so-called Herbig Ae/Be star, which has not yet started to fuse hydrogen in its core. Despite its youthful age of only a few million years, however, it already appears to be concerned with trying to produce offspring. And so, as humans are wont to do, they don’t look away considerately, but instead direct their eyes (and their telescopes) right at the action, full of curiosity...

How common is life in the universe?

The question is basically unanswerable. The well-known Drake equation feigns a certain degree of precision but suffers from the fact that it is nearly impossible to reach agreement on values for any of its seven factors. Right now, we have only one example for intelligent life, and for us to draw conclusions for the entire universe from just our own existence would, indeed, be very human, but would be scientifically problematic.

There is, however, an alternative. We could ask what the likelihood...