Galactic matters & supermassive black holes!

Been taking a break from the tsunami of "AI stuff" - pokes and pods about the Chat GPT and the absurd "moratorium petition" and such... and also from the USA's insane political meltdown. At a time when there are so many indicators that our confidence should be rising, not falling.

So... instead let's pause all that and take a break for science... especially spaaaaaaace.

Like wow. Let's start with an M dwarf sun with two Earth-sized worlds orbiting in the potentially habitable 'goldilocks belt.'

Indeed, roughly half of the galaxy’s sunlike stars may host rocky worlds in habitable zones where liquid water could pool or flow over the planets’ surfaces, according to one appraisal of Kepler mission data. By just that measure, the closest such world is probably within 20 light-years, and four should be within 33 light-years. Only, that doesn't even include the vastly bigger pool of ice-roofed ocean worlds like Europa that may exist near almost any star you see in the sky. Including those a mere 4 or 5 l.y. away.

How many alien civilizations are out there? “Of course, many factors determine whether a world in the habitable zone is truly friendly for life. Planetary characteristics such as magnetic fields, atmospheres, water content, and plate tectonics all play a role, and those are difficult to observe on small, faraway worlds,” writes Nadia Drake in National Geographic.

Expanding the search? It’s been almost 8 years since NASA scientists held a news conference predicting discovery of alien life within a decade. At least spectral signs of planetary atmospheres likely altered by biological activity, as our planet has been. While waiting for that milestone, what teams have appeared to accomplish is to survey 100,000 galaxies for the most blatant signs of total takeover by unrestrained techno ambition of super civilizations, of the sort seen in some garish sci fi. There may still be some Dyson Spheres and such, but not on a scale that would alter the smeared stellar light output of whole galaxies. So… there’s an upper bound, it seems. 

Disappointed? Wow, aren’t you the ambitious one.

== Galactic matters matter! ==

Only about 750 light-years apart, two supermassive black holes have been spotted feasting on cosmic materials as two galaxies in distant space merge. 

Also in the Milky Way, only 11,000 light years away, a pair of super massive stars whirl in a dance that recently produced one ‘fizzle’ supernova… and will likely then make another ‘fizzle’… followed eventually by a Kilonova spewing gold and other heavy elements across the galaxy. Beyond being amazing-fascinating… in my short story “The Tell” there is a beautiful spy named Kilonova. And why not?

Astronomers have spotted a runaway supermassive black hole, seemingly ejected from its home galaxy and racing through space with a chain of stars trailing in its wake. 

And what appears to be what is known as a dark galaxy. Aside from a small smattering of stars, the galaxy seems to be made up almost entirely of dark matter. The newly discovered dwarf galaxy located a mere 94 million light-years away is not emitting any optical light. In fact, it's barely emitting any light at all.

One possible explanation for “the dwarf galaxy problem is that  we're unable to detect some kinds of dwarf galaxy, such as those with very few stars, consisting primarily of gas and dark matter.  Found by radio observations of active hydrogen gas (galactic) without hardly any starshine. Calculations suggest that the galaxy is made up of around 98 percent dark matter.

A ’space tadpole” of gas may point to a rare intermediate scale black hole.

An interesting and well produced half hour video about the Rare Earth Hypothesis.

== Matters of scale ==

I already posted this content years ago… but the folks at Topia asked to publish a much glossier and more lavish version. “21 Cosmic websites you need to visit."

How big is space? Sci-fi legend David Brin investigates.” And now it’s even more fun than before.

Asteroid Apophis will skate by Earth in 2029, a terrific opportunity for orbit matching and deep study, if we start now. OSIRIS-REx, a spacecraft currently ferrying home samples from the surface of an asteroid called Bennu, will rendezvous with Apophis in 2029. Shortly after April 13, the craft — by then renamed OSIRIS-APophis EXplorer, or OSIRIS-APEX — will steer toward the asteroid until it is drawn into its orbit, eventually getting close enough to collect a sample from its surface.  But I think we should (and will) send more!

NASA discovers the perfect cave to live in on the moon: “Humans evolved living in caves, and to caves we might return when we live on the moon,” where there might be protection from radiation and meteorites and a balmy day-night (roughly) constant 63F temperatures and relative ease at sealing off large chambers. “Getting in and out of the pit wouldn’t be easy — the bottom is 328 feet below the moon’s surface, so it’d be like rappelling down a 30-story building.” (At NIAC we’ve funded a potential near-term lander to get a closer look at one of these!) “But if NASA can make it work, astronauts wouldn’t have to expend energy on yet-to-be-invented climate control systems for their future moon base.” Also one heckuva likely safer place!

Now to find one within reach of one of those polar ice fields… if so, you might start to change my mind about near-term NASA human-footprint missions like silly Artemis. But no, even this calls for robots first and then more robots to asteroids.

From the Mar Reconnaissance Orbiter: the HiRISE camera captured a Martian bear, its eyes formed by two craters. Or a case of pareidolia?

ABC reports that 12 new moons have been discovered orbiting Jupiter, which puts the planet's total to 92 - the most in the solar system.

A long, looping filament of plasma snapped over the sun's north pole, creating a 'polar vortex' that scientists can't explain.  If you want to come away with a vivid sense of 'being there'... may I recommend Sundiver?

== And yes SpaceX ==

I try not to use the name 'starship.' Anyway, the super-rocket (twice the thrust of Saturn V or SLS, almost) was a bigger success than it looked! It took off! It flew way up high past max-Q and near separation, despite lacking at least 4 thrusters that were likely smashed by chunks of concrete blasted from the launch pad. Sure the pad problems were kinda doofus and will take $$$$$ to fix. Still. Almost every failure mode that I saw looked solvable through the application of money and skill. I am optimistic.

== And speculatively… ==

Just watched a nice (if cursory/incomplete) survey post about alien machine probes that might be lurking in the Solar System, by the perceptive John Michael Godier. Very good and lots of fun, as usual.

I’ve long explored the “machine probe” concept from a lot of angles in both nonfiction and fiction – especially in Existence which dives into a very wide range of possibilities. (See the entertaining trailer).  That range of possibilities includes a huge variety of potential motives and speculations about probes that might be defunct, functional or somewhere in between. The classic scenario would be Arthur C. Clarke’s “The Sentinel” which became “2001/Odyssey”, though the Moon now seems off the table. Naturally, the asteroid belt seems a good maze in which to conceal such lurker machines, and indeed I deem that the one scenario to be the most likely to result in ‘alien contact’ during my remaining years. But there are recently discovered quasi-moons e.g those described by Jim Benford as possible lurker/observer sites.

I do disagree when Godier said that machine lurkers are similar to UFOs. Especially when you consider purported behavior… or indeed any other classic trait. In fact, I deem lurker probes and so-called UFOs to be almost polar opposites. One plausible, the other 99% blatant absurdity.  

If you want a Physicist-SETI-scholar, sci-fi author’s perspective on the recent UAP imbroglio, see my earlier posting: What's really up with those UAPs?  There are about 40 reasons why I give scant attention to UFO nuttery, even allowing for a slim 0.001% chance that - in defiance of Occam's Razor... a few 'sightings' might be silver guys flitting about in utterly nonsensical ways while demolishing every law of physics. Sure.

It's still not intelligent life. Nor is there much in that nutty crowd.