Showing all posts about astronomy
IC 1101 is the largest galaxy identified, so far, in the universe
14 August 2026
Located one-point-one-five billion light years from Earth, the behemoth galaxy, at one-point-seven-million light in years in length, somewhat dwarfs our home, the Milky Way, which measures in at a mere one-hundred-thousand light years across.
Using kiloparsecs as a metric, the size difference between IC 1101 and the Milk Way, the comparison comes into sharp focus, at five-hundred-and-twenty kiloparsecs versus thirty to fifty, respectively.
For reference, a kiloparsec equates to one-thousand paresecs. A paresec is three-point-two-six light years, not quite the distance from the Sun and Alpha Centauri, the closest star to Earth.
IC 1101 however is minute beside Alcyoneus, a galaxy sixteen million light years in size. Alcyoneus however is a radio galaxy, a body somewhat different to the likes of IC 1101 and the Milk Way.
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There is no escaping the solar system, not at speed anyway
12 August 2026
The Voyager 1 space probe is almost one light-day away from Earth. But the craft has been on its trajectory since being launched in 1977.
Deep space flights carrying people will need to move at far greater speed if they are to, for example, reach Alpha Centaur, the star system closest to the Sun, in a reasonable amount of time.
But travel at high speed, even relatively high speed, such as twenty-percent the speed of light, poses another set of problems. Minute particles litter the interstellar voids, and could severely damage a vessel, should a collision occur.
An object the size of playing marble would strike a ship with bullet-like impact given the speed involved. Vessels could be fitted with shielding of some sort, but the sheer volume of particle strikes would eventually destroy any protective cladding.
Unless a way can be found to overcome this problem, or the laws of physics can (somehow) be bent, humanity may well not be able to venture too far from the solar system.
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astronomy, physics, science, space exploration
When is an exomoon not an exomoon? When it orbits a failed star, not a planet
29 July 2026
Astronomers may have discovered the first moon, or satellite, outside the solar system, about seventy-three light years from Earth.
Plenty of exoplanets, planets orbiting stars other than the Sun, have been found, but this might be the first time a moon accompanying one of these bodies has been located.
But there’s a problem. The apparent exoplanet in question is a brown dwarf. These unusual Jupiter size objects often referred to as failed stars. But they are neither planet nor star.
That’s not all though. The brown dwarf hosting the would-be exomoon, is it self orbiting another star. The situation has scientists puzzled. From what I can understand, the moon of the brown dwarf has some substance. It is of a decent size. It is a real moon.
Quite unlike, for instance, the multitude of pebble-size excuses of “moons” orbiting Saturn.
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Could a super-Earth called Hestia be better than planet Earth?
30 May 2026
You won’t find Hestia, a super-Earth planet, on any of the charts, for this is a body imagined by Kurzgesagt. But Hestia, on paper at least, is a super-Earth in more ways than one.
No polar regions are present, ditto continents, though there are a multitude of medium size island land masses. The planet also sports shallow oceans, and an atmosphere far denser than Earth.
Combined, these conditions make Hestia an ideal spawning ground for all manner of complex lifeforms, including, possibly, intelligent life.
This would-be super-Earth also orbits in the habitable zone of an orange-dwarf star. The Sun meanwhile is a yellow-dwarf. Proxima Centauri, the next nearest star to Earth, is a red-dwarf.
Orange-dwarfs represent — at face value at least — a happy balance between the two. They are usually highly stable, and boast long lifespans, up to seventy-billon years, compared to about ten billion for stars such as the Sun.
A planet particularly conducive to life, hosted by a stable, long-lived star, increases the likelihood of intelligent life coming into being. Red dwarfs also have long lives, upwards of one trillion years, but that doesn’t always make them the ideal host for potentially life bearing planets.
Hestia also comes with four moons. Imagine a night sky adorned by not one, but four moons? What more could anyone want in a planet?
While such a place might make for an ideal life-friendly environment, it probably wouldn’t be suitable for humans. The surface gravity of a super-Earth can be up to three time that experienced on Earth. We might be able to adapt that sort of force, but it would be heavy going.
Multiple moons might also pose problems, depending on their proximity. If they are too close, the host planet may see more boisterous ocean tides, and increased seismic and volcanic activity.
Then there’s the matter of Hestia’s thirty-six hour day, something that might take some getting used to. But, if we’re trying to find life elsewhere in the universe, planets like Hestia, orbiting in the habitable zones of orange-dwarf stars, are what we should looking out for.
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astronomy, exoplanets, science
Dust busters will be needed to keep Moon bases free of dust
20 April 2026
From the European Space Agency (ESA) blog:
The “lunar hay fever”, as NASA astronaut Harrison Schmitt described it during the Apollo 17 mission created symptoms in all 12 people who have stepped on the Moon. From sneezing to nasal congestion, in some cases it took days for the reactions to fade. Inside the spacecraft, the dust smelt like burnt gunpowder.
What a headache insignificant specks of dust will pose for the planners of future lunar bases. Airlocks will need to be designed so they keep Moon dust well away from the inhabitants of a base.
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astronomy, science, space exploration
Artemis II returns safely to Earth despite heat shield concerns
13 April 2026
Splashdown occurred at about ten o’clock in the morning in my part of the world. I had been dreading the fiery re-entry phase of the flight, after a number of commentators expressed doubts as to the integrity of the return vehicle’s heat shield. Thankfully all was well in the end.
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astronomy, science, space exploration
Forget artificial intelligence, aliens may usurp humanity instead
8 April 2026
When people are in competition, they work harder if the game seems winnable, and decrease effort if they think they’ll lose. It’s implied that because humans are so far behind aliens, we are uncompetitive and so should put in less effort.
There’s — somehow — an idea, published on Marginal Revolution, that technologically advanced extraterrestrials have placed alien drone probes, which evade detection, across the solar system. These devices — if they exist — are apparently keeping an eye on what’s happening on Earth.
I even double checked the date the article was posted: Saturday 4 April 2026. So it wasn’t some sort of April Fool’s caper. On the other hand of course, Artemis II was on the way to the Moon by then.
The question though, what should we do if there are surveillance probes within the solar system? And who knows, maybe aliens are watching us. Maybe extraterrestrials indeed exist — there’s surely at least one intelligent alien civilisation somewhere in the universe — and they’ve found us.
But why they don’t make their presence known puzzles me. All those UAP sightings over the last several decades have somewhat given the show away, have they not? Let’s see you, not your incredible interstellar-space travel capable vessels.
But if we don’t want extraterrestrials to wipe us out, or simply stop us travelling beyond the limits of the solar system — things they may want to do — we need to lift our game. Work harder. Be more ambitious. Even if we remain uncompetitive in comparison. We also all need to work together.
If that’s possible. And if it’s not, I think that’s why they call it the great filter.
What a situation to be in.
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Fears the Artemis II heat shield may not be safe
1 April 2026
On the eve of the launch of NASA‘s Artemis II ten-day Moon flyby mission, Maciej Cegłowski warns that the heat shield of the Orion spacecraft and command module, which the crew will use to return to Earth’s surface, is not safe:
In a nutshell, Camarda argues that NASA is demonstrating the same dysfunction that led to the Columbia and Challenger disasters. Faced with an unexpected engineering failure, it has built toy models to convince itself that the conclusion it wants to reach (it’s safe to fly) are supported by evidence. These toy models are not grounded in physics, but because they appear to be quantitative, they create a false sense of security and understanding, an epistemic fig leaf for management to hide behind.
Cegłowski is not alone, and concerns about the re-entry vessel’s heat shield have been widely flagged in recent weeks. At this late stage in proceedings it can only be hoped NASA’s assurances that the heat shield is safe can be taken at face value.
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astronomy, science, space exploration
No sign of extraterrestrial life? Blame it on bad space weather
18 March 2026
In the search for evidence of intelligent extraterrestrial life, astronomers, and organisations like SETI, often seek out narrowband radio signals.
Space is full of radio signals, most of them broadband, which usually occur naturally. Neutron stars are but one generator of such signals. Narrowband radio transmissions, on the other hand, are somewhat more likely to be created by an intelligent civilisation. On Earth, for instance, TV transmissions and mobile phones, are among sources of narrowband radio signals.
It makes sense then to look out for such signals in deep space. But some recent research conducted by SETI suggests narrowband radio signals may be disrupted by chaotic flows of ionised gas, and other sources of turbulence in the cosmos:
A new study by researchers at the SETI Institute suggests stellar “space weather” could make radio signals from extraterrestrial intelligence harder to detect. Stellar activity and plasma turbulence near a transmitting planet can broaden an otherwise ultra-narrow signal, spreading its power across more frequencies and making it more difficult to detect in traditional narrowband searches.
We keep coming up with explanations to account for the apparent absence of intelligent extraterrestrial life elsewhere in the universe. Now we’re blaming the weather.
The smart money says there is intelligent life somewhere in the cosmos, but it may not be all that common, nor particularly close to us. There’s a lot of space out there, beyond the solar system.
The size of the galaxy, to say nothing of the universe, is something many of us struggle to comprehend. Even if humanity possessed the means to travel at speeds close to the velocity of light, it would take over four years just to reach Proxima Centauri, the star presently closest to the Sun.
To visit the centre of our galaxy, the journey would take over twenty-five thousand years.
That’s not insignificant. In fact, twenty-five thousand light years constitutes a vast amount of space. An alien civilisation could be tucked in there somewhere, but it might take thousands of years for evidence of their presence to become apparent.
On paper, the chances of the existence of intelligent extraterrestrial life are better than even.
There are potentially millions, if not more, of exoplanets with environments conducive to complex life in the Milky Way galaxy alone. And if intelligent life can take hold on Earth, it can surely take hold elsewhere. But there are those who think intelligent life on Earth is a fluke, and a lot of things had to go the right way, over a period of billions of years, for this to happen.
Bad “weather” in deep space may well be playing a part in concealing the presence of extraterrestrial technological civilisations. But their scarcity, and extreme distance — potentially tens of thousands of light years — from Earth, probably better explains why there is no sign, yet, of anyone else.
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Universe to astronomers: I am stranger than you imagine
4 December 2025
Kurzgesagt making sense of a non-sensical universe:
For decades, we’ve had a beautiful theory of the cosmos. One that explained how the universe began, what it’s made of, and how it’s supposed to behave. It matched our observations astonishingly well and made us feel like we’d almost deciphered the cosmic code. But in the last few years, as our telescopes got better and our data sharper, cracks started to appear. Strange mismatches between what the theory predicted and what we actually saw.
British astronomer Arthur Eddington wrote in a book published in 1927, saying: “not only is the universe stranger than we imagine, it is stranger than we can imagine.” He was riffing on the words of compatriot scientist J. B. S. Haldane, who wrote, also in 1927: “now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose.”
Stranger. Queerer. Take your pick.
These people nailed the nature of the universe one hundred years ago, with a fraction of the knowledge we have today. And what we know now will likely only represent a mere fraction what we’ll know in another one-hundred years. I think it’s a little too soon to say we’ve figured out the universe.
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