Showing all posts tagged: science
These are end days for the Voyager space probes
4 December 2024
It almost seems inconceivable that, one year soon, deep space probes Voyager 1 and 2, will cease to function. At some point their on-board power reserves will be completely drained, rendering the vessels unable to collect data, and send it to mission controllers on Earth. We know their batteries will go flat sooner or later, and what equipment that hasn’t yet failed, will eventually. But by the time that happens, they may have been operational for fifty-years.
Both probes have experienced numerous faults of some sort, which mission controllers have mostly been able to rectify. Despite them being almost a light-day distant. Boosting their supply of power, being able to somehow recharge the batteries though, is unfortunately not a solution that can be effected. Various on-board systems can be shut down, but that only acts to conserve power, not replenish it. It’ll be a strange day, the day we learn we’ll no longer hear from either vessel.
Still, the New Horizons probe, which flew passed Pluto in 2015, is still operating as far as I know, so maybe we’ll continue to hear from at least one of our deep space emissaries, after the lights go off on the Voyager probes.
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astronomy, science, technology
The Wow! signal, sun-like stars, and an abundance of hydrogen
28 November 2024
Did an extra-terrestrial intelligence attempt to message us in the distant past? Or did an Earth based radio telescope, nicknamed Big Ear, inadvertently eavesdrop in on a snippet of a conversation between two other alien civilisations? These are among some of the many explanations advanced to understand the so-called Wow! signal, a suspected narrowband radio transmission detected by Jerry R. Ehman, an astronomer working on an early inception of the SETI Project, almost fifty years ago.
Despite being a narrowband signal, which might indicate the presence of intelligent life somewhere, there could any number of explanations to account for the supposed transmission. Some sort of natural phenomena, one we do not yet understand, may well be the cause.
But that hasn’t stopped anyone from daring to live in hope, even though no identical, or repeat, signals have seemingly been observed since. Alberto Caballero, a Spanish astronomer, using data collected by the Gaia space observatory, analysed the area of the galaxy where the Wow! originated. He found about sixty stars, similar to our star, the Sun, in the region. For people searching for signs of extra-terrestrial intelligence, sun-like stars are a common starting point.
If intelligent life emerged here on Earth, a planet orbiting a G-Type main-sequence star, the Sun, then just maybe the same could happen on an Earth-like plant, around another star similar to the Sun, somewhere else. In his research, Caballero identified a candidate star of particular interest to him, with the catchy name of 2MASS 19281982-2640123, located some eighteen-hundred light years from us. Take a second to consider that. Travelling at the speed of light, the would-be transmission was sent during the height of the Roman Empire.
But, in a galaxy quite possibly devoid of intelligent life, with the exception of humanity — if current indications are anything to go by — how incredible would it be that a narrowband-radio-signal-transmitting-alien-civilisation turned out to be — on a cosmological scale — a mere hop, skip, and jump, away?
2MASS 19281982-2640123, and any planets the star may host however, was eliminated after a radio telescope scan last year. Observations, conducted by two radio telescopes, failed to detect any technosignatures, which would point to the presence of a technological civilisation. But not all is lost, there are another sixty or so possible stars Caballero, and other astronomers, could look at next.
Then again, for those hoping the Wow! was sent by someone, far, far away, perhaps all is lost. Fred Watson, an Australian astronomer, writing for Australian Geographic, says some new research conducted by American and Colombian scientists, has discovered numerous instances of Wow! signal like phenomena throughout space:
In research recently announced, a team from the USA and Colombia have used data from a since decommissioned radio telescope at Arecibo in Puerto Rico to look for similar phenomena to the Wow! signal. And they’ve found them, differing only from the original in their lower intensity. All these signals carry the wavelength signature of cold hydrogen, the most abundant element in the universe. It’s commonly expected to be the preferred wavelength for communication by intelligent extraterrestrials — hence the Big Ear’s tuning to this wavelength in the original SETI experiment.
This is not the first time hydrogen has been theorised to be somehow responsible for the Wow!. In 2017, a group of researchers at the Center of Planetary Science said they had determined a hydrogen cloud, accompanying a comet, that was in the region of the galaxy where the Wow! was detected, was the cause. Other scientists, however, were not comfortable with the idea.
It remains to be seen what other astronomers make of the conclusion of the American and Colombian scientists. It seems to me though, the remaining, unchecked sun-like stars, and any surrounding planets, Caballero suspects may be the origin of the Wow!, should be looked more closely anyway. Because one never knows what lurks behind all that hydrogen.
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Unfortunately, colonising Mars is not a great idea
23 September 2024
There’s the challenge. There’s the adventure, the pioneering spirit, of setting off to another planet. Not everything is, or should be, easy. But are those really the right reasons for wishing to establish a human colony on the fourth rock from the Sun, Mars?
Mars does not have a magnetosphere. Any discussion of humans ever settling the red planet can stop right there, but of course it never does. Do you have a low-cost plan for, uh, creating a gigantic active dynamo at Mars’s dead core? No? Well. It’s fine. I’m sure you have some other workable, sustainable plan for shielding live Mars inhabitants from deadly solar and cosmic radiation, forever. No? Huh. Well then let’s discuss something else equally realistic, like your plan to build a condo complex in Middle Earth.
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Another day, another problem with Voyager 1, solved
20 September 2024
Data the nearly fifty-year old deep space probe was returning to Earth earlier this year, was getting all scrambled up. But dutiful mission controllers sorted that out. This despite Voyager 1 being so far away that it’d take a day to reach, assuming we had a vessel that could travel at the speed of light.
More recently, Voyager 1 has been having have trouble using correcting thrusters that keep the probe’s antenna pointed at Earth. Fuel pipes to the aging thrusters have begun to clog up, rendering them inoperative. Mission controllers, at the Jet Propulsion Laboratory, in California, however have been able to re-activate another set of thrusters — unused in decades — and effect a fix.
As a result of its exceptionally long-lived mission, Voyager 1 experiences issues as its parts age in the frigid outer reaches beyond our solar system. When an issue crops up, engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have to get creative while still being careful of how the spacecraft will react to any changes.
If you want a tricky problem solved, ask a mission controller from one of the automated space missions to help. And of course Apollo 13.
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astronomy, science, technology
Gravitational waves may reveal presence of warp drive starships
13 September 2024
Gravitational waves have been helping scientists and astronomers answer some of the big questions of the universe. But gravitational waves may be able to do something else: detect the presence of vessels with Star Trek like warp drive engines, as they move through the cosmos.
One problem with the warp drive space-time is that it doesn’t naturally give gravitational waves unless it starts or stops. Our idea was to study what would happen when a warp drive stopped, particularly in the case of something going wrong. Suppose the warp drive containment field collapsed (a staple storyline in sci-fi); presumably there would be an explosive release of both the exotic matter and gravitational waves. This is something we can, and did, simulate using numerical relativity.
I imagine a cloaking device wouldn’t be much help, if a vessel was trying to move about unnoticed. The gravitational waves generated by the ship’s warp drive would pretty much render it visible.
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Add new Australian volcanic activity to the list of worries…
6 September 2024
As if climate change, and the increasingly unstable weather it will bring, isn’t enough to worry about, parts of Australia may see an increase in volcanic activity. Not in the immediate future, thankfully, but at some point nonetheless:
It is much less likely that a volcano that has already erupted will start again. It is a lot more likely a new volcano will form somewhere else. That is almost a given. It is going to happen. The follow-up question is when is this going to happen? It may be in 100 years, or 5,000 years. We don’t know. We need to have more information to answer that question.
I’m unsettled by this lack of certainty here… one-hundred years isn’t really much. Nor, for that matter, is five-thousand years, speaking in geological terms. Let’s hope these new volcanoes appear later rather than sooner, or ideally, not at all.
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Vacuum decay, one more existential threat to lose sleep over
22 August 2024
Tooth decay. Entropy. Heat death of the universe. These are things to worry about, and we’ve known about them for a long time. But recently scientists have identified something else to lose sleep over: vacuum decay:
Vacuum decay, a process that could end the universe as we know it, may happen 10,000 times sooner than expected. Fortunately, it still won’t happen for a very, very long time.
There’s a lot of theoretical physics (I think) involved, which is way over my head, so there’s not more I can say about vacuum decay. The good news however: vacuum decay will not bring about the end of the universe anytime soon.
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The physics of running and keeping fit on the Moon
8 July 2024
Rhett Allain, writing for Wired, looks at the physics of this important question.
If humanity is ever to establish bases on the Moon, ways of keeping occupants fit in the low lunar gravity need to be worked out. A wall of death sort of gizmo, that’s a little like a stationary hamster-wheel, but turned on its side, that emulates Earth-like levels of gravity, may be a solution. But there might be more effective alternatives.
But check out the article’s artist impression of a suited up astronaut “jogging” on the surface of the Moon. Straight up running in this way is a fanciful keep fit option unfortunately, as simple as the idea may at first seem. It’s too bad though, because what a sight it would be to behold: Earth floating in the lunar sky, as you ran.
I doubt Earth would be quite as big as depicted in Nzoka John’s image, but it still be quite the spectacle. And on the subject of what Earth might look like from the surface of the Moon, a gallery of images by American illustrator and writer Ron Miller, depicting how other planets in the solar system would appear from Earth, if they were as close as the Moon.
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art, astronomy, illustration, physics, science
Potentially habitable Earth size planet forty light years away
4 July 2024
That’s the good news. Tory Shepherd, writing for The Guardian, says the recently discovered exoplanet, dubbed Gliese 12b, might be able to host liquid water. We all know what that means. If there’s water, there may be life. Gliese 12b is so named because it orbits a star called Gliese. Now for the bad news. Gliese is a red dwarf.
I personally don’t have a problem with red dwarf, or M-type, stars. They’re actually kind of cool. And common. Up to seventy-five percent of stars in the cosmos are thought to be red dwarfs. The star nearest to Earth, Proxima Centauri, is a red dwarf. And while most stars in the universe have relatively short lifespans — for instance the Sun, which is about half way through its ten billion year life — red dwarfs live for trillions of years.
The last stars — as we currently understand them, at least — shining in the universe, will be red dwarfs. Go the red dwarfs. But, the problem is any planets orbiting in a red dwarf’s habitable-zone, will be tidally locked. That is, only one side of the planet will face its host star. That half of the planet therefore, in this case Gliese 12b, will be overly warm, while the other, dark side, will be rather cold.
This may not be particularly conducive to life. But some scientists have suggested life on planets orbiting red dwarfs in the habitable-zone, may take hold near the day-night terminator. This is where it will be neither too hot, nor too cold. But this would be an extremely narrow corridor, somewhat limiting the chances of life, especially intelligent life, developing.
Then there’s the red dwarfs themselves. They’re prone to regularly emitting intense radiation flares, which could have the effect of sterilising the surface of nearby planets. This points to the likelihood of Gliese 12b not being all that habitable at all. I think we need to reserve our excitement for the discovery of habitable Earth size planets, for maybe when they’re found orbiting other types of stars.
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Did the universe exist before the Big Bang? Maybe…
27 June 2024
What happened, or was there, before the Big Bang that is said to have brought the universe into being? Was there nothing, to which something came? It is the question of the ages.
In his recent documentary series, Universe, British physicist Brian Cox posits that the universe existed before the Big Bang. How long this pre Big Bang entity had been there, or its origins, remain unknown however. How fascinating these before-the-beginning sort of questions are.
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