from the where's-Kevin-Costner-when-you-need-him? dept.
An international team of researchers led by Charles Cadieux, a Ph.D. student at the Université de Montréal and member of the Institute for Research on Exoplanets (iREx), has announced the discovery of TOI-1452 b, an exoplanet orbiting one of two small stars in a binary system located in the Draco constellation about 100 light-years from Earth.
The exoplanet is slightly greater in size and mass than Earth and is located at a distance from its star where its temperature would be neither too hot nor too cold for liquid water to exist on its surface. The astronomers believe it could be an "ocean planet," a planet completely covered by a thick layer of water, similar to some of Jupiter's and Saturn's moons.
[...] The exoplanet TOI-1452 b is probably rocky like Earth, but its radius, mass, and density suggest a world very different from our own. Earth is essentially a very dry planet; even though we sometimes call it the Blue Planet because about 70% of its surface is covered by ocean, water actually only makes up a negligible fraction of its mass — less than 1%.
[...] "TOI-1452 b is one of the best candidates for an ocean planet that we have found to date," said Cadieux. "Its radius and mass suggest a much lower density than what one would expect for a planet that is basically made up of metal and rock, like Earth."
[...] An exoplanet such as TOI-1452 b is a perfect candidate for further observation with the James Webb Space Telescope, or Webb for short. It is one of the few known temperate planets that exhibit characteristics consistent with an ocean planet. It is close enough to Earth that researchers can hope to study its atmosphere and test this hypothesis. And, in a stroke of good fortune, it is located in a region of the sky that the telescope can observe year round.
Journal Reference:
Charles Cadieux, René Doyon, Mykhaylo Plotnykov, et al. TOI-1452 b: SPIRou and TESS Reveal a Super-Earth in a Temperate Orbit Transiting an M4 Dwarf [open], AstronJ, 164, 2022. DOI: 10.3847/1538-3881/ac7cea
(Score: 5, Interesting) by Immerman on Friday August 26 2022, @12:54PM (17 children)
Speculation on what such a world would look like:
I did the math, and assuming a rocky core of Earthlike density surrounded by water at 1g/cc (and that my early-morning math is correct) I'm getting that 30% water by mass translates to:
- The rocky core masses 2.3x the water
- The rocky core extends 67% of the way to the water's surface
So we're talking an ocean thousands of miles deep, almost certainly nothing reaches the surface.
At the sea floor, would pressure heating already have heated the environment to the point that the rock is liquid or plastic? Or would water convection have mixed that heat more evenly?
Tectonic activity? Would there be energy-rich mineral plumes around volcanic vents to give proto-life a place to start?
(Score: 0) by Anonymous Coward on Friday August 26 2022, @01:08PM (7 children)
I wonder what large impacts would have done to a planet like that. It would have put a lot of energy into the water, moving a lot of it into the atmosphere for some amount of time, and perhaps disassociating some of the water to produce oxygen as well? I would assume a body with a lot of water would have a non-negligible amount of water vapor in the atmosphere, so you'd think you'd be generating ozone as well if there is enough UV coming from the host stars.
(Score: 4, Interesting) by Immerman on Friday August 26 2022, @01:27PM (6 children)
I suspect any oxygen produced that way would rapidly recombine with the hydrogen. Oxygen is so reactive that it's almost impossible to keep it around unless it's being continuously produced in large quantities. Though I suppose the hydrogen might escape into space.
Though without surface minerals to oxidize the options are really only that, or dissolving into the water. So if oxygen-producing life evolved there then you wouldn't see the huge lag times between oxygenating the oceans and oxygenating the atmosphere.
Of course, with an ocean a thousand times deeper than ours it would take a *lot* longer to oxygenate that. In fact it might be a real challenge to do so if a semi-molten sea floor was steadily dissolving non-oxidized materials into the water. Could it possibly be a world where oxygenation was functionally impossible?
(Score: 2) by JoeMerchant on Friday August 26 2022, @01:44PM (5 children)
Oxygen producing life isn't necessarily dependent on oxygen consuming life... seed that ocean with some phytoplankton and see what happens.
There may be a limit of how much oxygen the phytoplankton can produce, due to (extra)solar energy input and nutrient mix in the water, and that limit may butt up against the oxygen consuming processes in the deep ocean, reacting oxygen with minerals to make new minerals, but the pond scum should continue to crank it out in any case.
We have an ocean several miles deep, almost covering the surface, and our "great oxygenation event" got us to 21% steady state today, would be higher without oxygen consuming life in the mix. I suspect that, given an oxygen environment even as low as 5%, oxygen consuming life would still evolve - starting with phytoplankton eaters and going from there.
Somethings that always bothers me about Sci-Fi universes with thousands+ of separately evolved species are:
A) how they all speak English - ok, explain that one away with AI translators - but how did translators that intelligent not turn into SkyNet?
B) how 90%+ seem to be four limbed bipeds with their brain on a stalk, human like mouth, etc. I know, it keeps the makeup department simple, but c'mon...
C) how 95%+ of them breathe compatible atmospheres - ok, explain that one away with: like mixes with like, the methane breathers keep mostly to themselves.
D) and this one is _rarely_ addressed: how we all function on basically the same timescale. You could try to explain it like C) but... certainly species that are only ~2x apart in basic functioning speed would still interact / intermingle quite a bit. You might say that the basic chemical processes run at similar rates, at least for life that's not radically faster (silicon computers, for example) or slower (Niven's hydrogen gas creatures) - but... even on Earth we've got Cheetah and Sloth in basically the same environment...
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Immerman on Friday August 26 2022, @01:59PM
Sure, oxygen producers evolved long before oxygen consumers - they kind of have to. And the toxic oxygen wiped out most existing life in between. I'm just thinking that a semi-molten sea floor might be so reactive that you couldn't have a great oxygenation event at all, even of the oceans, much less the atmosphere. That could possibly make for a much slower pace of life - oxygen is a great high-power fuel source.
(Score: 3, Interesting) by NotSanguine on Friday August 26 2022, @02:24PM (1 child)
There's an important reason for those things. Exemplified by JMS' [wikipedia.org] (creator of Babylon 5 [wikipedia.org]) answer when asked "how fast can Starfuries [fandom.com] go?" That answer being: "At the speed of plot."
When it comes to fiction, science must always bend to the needs of the storyteller.
No, no, you're not thinking; you're just being logical. --Niels Bohr
(Score: 2) by JoeMerchant on Friday August 26 2022, @07:25PM
>science must always bend to the needs of the storyteller
The world abounds with very needy storytellers, indeed.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by drussell on Saturday August 27 2022, @08:42PM (1 child)
According to Star Trek TNG S6E20, "The Chase," they all came from a common ancestor who intentionally spread their genetic material across the galaxy after realizing they were alone, the first beings to so develop in the entire galaxy at the time.
(Score: 2) by JoeMerchant on Saturday August 27 2022, @09:13PM
>TNG S6E20, "The Chase," they all came from a common ancestor who intentionally spread their genetic material across the galaxy after realizing they were alone
And that was a nice try. Still has a problem with time scales, with Earth in the early group of highly developed cultures - the progress Earth makes in 500 years as compared to the (scant) millions it would take to evolve the varying features shown in the alien species, Vulcan, Earth, Klingon, Romulan, etc. would be HIGHLY unlikely to be so closely matched in technological development after all that time.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by deimtee on Friday August 26 2022, @01:43PM (8 children)
At least some primordial hydrocarbons are going to float. You might have thousands of km of water, but floating on top you are going to get hundreds of km of oily scum. Probably a methane nitrogen atmosphere. If you can get some water vapor through the oil layer then stellar UV is going to give you lots of weird recombinations.
All up, it sounds like an excellent candidate for ET life even if it's just microbe level.
No problem is insoluble, but at Ksp = 2.943×10−25 Mercury Sulphide comes close.
(Score: 2) by Immerman on Friday August 26 2022, @02:21PM (6 children)
Where would the material for all these km of scum come from if the world has a roughly Earth-like composition, aside from all the extra water? We're not buried in km of oily scum here. Even if an entire 1 bar worth of atmosphere were somehow liquefied into scum you're still only be talking maybe 15m.
Also, current popular thinking is that protolife probably evolved in thin films on the surface of solids for some degree of structure - such as on the surface of rocks around hydrothermal vents (which provide energy-rich chemical fuel to the equation).
Floating scum-mats might provide that structure - but on the surface you also have to worry about UV destroying proto-life before it forms.
(Score: 3, Interesting) by JoeMerchant on Friday August 26 2022, @07:32PM (4 children)
Given all that geo-thermal energy and all those chemicals at the bottom of the ocean, I'd expect "first life" to be starting down there, rather than on the thrashing surface of the water-air interface in the (relatively) feeble light of the sun.
Once first life starts successfully spreading, it's pretty much game-over for the competition.
Long ago, in a bash shell far far away, I "created" an artificial life sim.
Those bugs would typically bumble around with my "god given" genome, slowly reproducing, barely keeping the species going, until... some mutation would figure out the magic balance with which to rapidly reproduce without dying out due to energy expenditure on reproduction - then that thing would replicate itself like crazy, taking over the whole space of the simulation.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by Immerman on Friday August 26 2022, @08:19PM (3 children)
That's what I was thinking too.. but then I started thinking pressure.
They estimate this world at 70% larger than Earth - let's be conservative and say that's volume, so 20% larger radius. At 33% the planet's radius the ocean would be ~1,600km deep.
At that depth you're looking at over 150,000 atmospheres of pressure! Chemistry starts behaving strangely at high pressure - I understand one of the reasons life is so scarce on the floor of the Marianas trench is that a lot of biochemistry just stops working reliably at those pressures, and that's only ~11km down at it's deepest, and a bit over 1,000 atmospheres. It's unsettling to think the deepest highest-pressure depths of our ocean could be less than 1% as deep as this world's "shallows".
Life that evolved based on chemistry at those pressures might have a hard time spreading upwards. If there were enough dissolved nutrients and calories in the water I'm sure they still would eventually - every little improvement in low-pressure tolerance opens more uncontested territory after all. But the higher you go in the water column, the less calories are available, already consumed by life closer to the source. There might be a huge dead zone in the upper reaches of the water, without enough available energy to feed a surface population that could eventually evolve photosynthesis to provide an alternate energy source.
(Score: 2) by JoeMerchant on Friday August 26 2022, @09:43PM
Certainly would be interesting to visit, with a craft capable of exploring the surface and the depths.
I am guessing that there are "things" that work at all kinds of temperatures and pressures, and with a volume of soup that large the potential biosphere is on the order of 100x that of Earth.
It already amazes me how well creatures like air breathing whales function at 100 atmospheres of pressure when they go down for some calamari sushi, not to mention how easily the squid of the deep come to the surface and return to the depths as they like.
For that matter, I recently learned that human "freedivers" are extending their breath-hold times beyond 10 minutes, some beyond 20: https://www.guinnessworldrecords.com/news/2021/5/freediver-holds-breath-for-almost-25-minutes-breaking-record-660285 [guinnessworldrecords.com] I thought that brain damage started after five minutes, but maybe it still does in these people too... Throw a little biochemical evolution into the mix and all kinds of weird things are possible.
But "the Trench" yeah, that's pretty desolate - unless you're a beer can. If there were abundant thermal vents down there, I'm relatively sure life would find a way through the pressure problems, but with little energy and being such a relatively small biome, it does make sense that it appears desolate in our brief hit and run surveys. I also bet that if a research sub went down with good observational tools and had 400 hours to "look around" they'd find all kinds of living things that we're currently overlooking.
Україна досі не є частиною Росії Слава Україні🌻 https://news.stanford.edu/2023/02/17/will-russia-ukraine-war-end
(Score: 2) by legont on Saturday August 27 2022, @12:51AM (1 child)
I'd think life with less available nutrients would eat life with more.
What's more interesting, how would those guys get into space to concur the galaxy.
"Wealth is the relentless enemy of understanding" - John Kenneth Galbraith.
(Score: 2) by Immerman on Saturday August 27 2022, @02:19PM
Yeah, nutrients would probably be fine. Calories though run out - once you use the energy from your food, that energy is *gone*, someone who eats you won't get it. And if the only source of energy is geothermal chemistry being released a thousand kilometers below you, if there's enough life consuming it before it gets to you there's not going to be much left - and whoever eats you is getting even less of it.
I suppose you'd still likely get something akin to deep earth microbes though - living in extreme slow motion, eking out survival from the slight trickle of chemical energy they can scavenge.
(Score: 2) by deimtee on Friday August 26 2022, @09:58PM
Same place the thousands of km of water come from, the collapsing gas/dust cloud that formed the system. Look at the composition of the moons of Jupiter and Saturn, which is what the article compares it to. If the local star wasn't energetic enough to blow away most of the water (or dissociate it into H and blow that away), like the Sun did with Earth and Venus, then it won't have blown away the carbon either.
No problem is insoluble, but at Ksp = 2.943×10−25 Mercury Sulphide comes close.
(Score: 2) by isostatic on Saturday August 27 2022, @03:29PM
Oil you say? Sounds like we need to export some freedom to them!