- 31,874
- 125,085
The Astronomy Thread
- Thread starter Araxen
- Start date
Tuco
I got Tuco'd!
- 45,426
- 73,489
Was my first thought too. I don't have any kind of education to even surmise it, but I just imagine that biological markers are only high confidence within a narrow set of assumptions.
Ukerric
Bearded Ape
- 7,920
- 9,571
The inorganic chemistry ("industrial production") doesn't seem that exotic too. Some phosphate inorganic compound, lots of heat (Venus, LOL), and a catalytic which is apparently the part that's "missing" for Venus. So my guess is that there's another, slightly more harder, inorganic pathway that can constantly produce small quantities of phosphine.
That one's probably far more likely than microbes, but since it's "unknown", while microbes are "known", the microbe hypothesis is considered top contender for now.
Lambourne
Ahn'Qiraj Raider
- 2,715
- 6,525
Even if it's microbes, you'd still want to know if they are Earth organisms that somehow ended up there or if it's truly independently formed life. Asteroids can travel from one planet to another, or maybe we put them there inadvertently. Don't think we can know for sure without a a sample return mission.
I do think life may well be common throughout the galaxy, even if intelligent life isn't. Some serious astronomers used to argue that the Sun might be the only star with planets, everything we've learned in the last 20 years indicates that planets are not only not rare but are in fact quite common. I can't think of a reason that would make Earth unique in a way that can't be replicated around some percentage of other stars.
I do think life may well be common throughout the galaxy, even if intelligent life isn't. Some serious astronomers used to argue that the Sun might be the only star with planets, everything we've learned in the last 20 years indicates that planets are not only not rare but are in fact quite common. I can't think of a reason that would make Earth unique in a way that can't be replicated around some percentage of other stars.
- 2
- 1
Ukerric
Bearded Ape
- 7,920
- 9,571
Everyone's chasing that elusive Great Filter.
(and yes, finding any non-Earthborne form of life IN our own solar system ends up pretty bad news)
Cybsled
Avatar of War Slayer
- 16,454
- 12,099
I still don’t buy that filter hypothesis. Is it reasonable that a civilization or species ends for various reasons? Sure, we see it all the time. But life being common in the universe doesn’t mean we’re fucked because we haven’t encountered advanced life.
- 2
Big Phoenix
Pronouns: zie/zhem/zer
- 44,633
- 93,239
iirc theres been like 7 or 8 probes that have either landed on the surface of Venus or floated in the atmosphere for some time.
Its an interesting thing to think about.
For example at 2g you basically need a rocket the size of a Saturn V to put just a person in low orbit. So high gravity really makes it hard if not impossible to build rockets that can deliver useful payloads into space. Too low gravity and maybe youre doomed to just end up like Mars, a planet with tenuous atmosphere incapable of supporting life.
Look at the radical differences between Venus > Earth > Mars. Why did Venus end up under going a runaway greenhouse effect while the Earth hasnt? Why did Mars lose almost all of its atmosphere?
Last edited:
Araxen
Golden Baronet of the Realm
- 10,248
- 7,595
- 2
Lambourne
Ahn'Qiraj Raider
- 2,715
- 6,525
Many things have been proposed to explain Earth's unique life-supporting status, particularly our relatively large moon which stabilizes Earth's axial tilt. Earth's magnetic field. Another is Jupiter's relatively nearby orbit, serving as protection from comets (it's hard to overstate just how massive Jupiter's gravitational influence is, it makes up nearly 3/4s of the total mass in orbit around the Sun by itself)
Mars is a warning to Earth really, It's plausible that it could have supported life at some point in the past, but it shows that the time that a planet can support life is limited. Earth's time will run out too, and at this point humans are the only species that can do something about it.
If there's a great filter, the leap to human level intelligence may well be it as life managed perfectly fine without it for a very long time. It might well have kept going as it was until the Sun died and took life out with it. Countless millions of species have been on Earth, from microbes to funghi to plants and animals, and only one has become smart enough to even see the danger life is in, and only in the last 60 years did we develop the technology to actually do something about it. Never did drugs but I imagine this is one of those things that could cause one existential dread on a trip.
Kiroy
Marine Biologist
- 34,621
- 99,926
Tectonic activity has a lot to do with keeping things going as well
- 1
Cybsled
Avatar of War Slayer
- 16,454
- 12,099
Venus had lots of things that impacted it: Slow rotation (a Venus day is pretty much the same as a year), no plate tectonics, no magnetic field. I would be curious if the slow rotation was the eventual result of the thick atmosphere, or if something else caused that. Slow rotation would have massively fucked up heat distribution.
Mudcrush Durtfeet
Hungry Ogre
- 2,428
- -758
- 4,107
- 4,043
a molten core also does the magnetic field stuff, right? But That must be a stage of a rocky planet's life cycle. I am guessing someday the earth's core will cool and that will radically affect the earth's strong magnetic fields. They won't be strong anymore.
I think that is how it works. Mars used to have a more molten core. Now it's like Navy coffee.
- 1
Burns
Golden Baronet of the Realm
- 6,118
- 12,324
The molten core allows the dynamo, that causes the magnetosphere, to exist and Earth's core wont cool as long as we have the moon. I think it goes something like this:
Due to the mass of our huge moon, in comparison to the earth, the center of rotation of the two celestial bodies is off center in relation to center of earth's rotation. This is enough to cause major currents in the core that keep the dynamo churning (along with other processes), and adds the energy to prevent the core cooling. We are slowly loosing the moon, but the sun goes red giant before the moon gets too far away to stop this, and allow the core to cool.
- 2
- 4,107
- 4,043
Ah!! I forgot about the Moon's role in all this. That's right, the Moon is a major part of our equation. Also for life evolution. Tides were probably the laboratory mechanism that gradually grew land life over time.
- 1
Blazin
Creative Title
- 6,397
- 33,557
Big Phoenix
Pronouns: zie/zhem/zer
- 44,633
- 93,239
Mercury has a magnetic field, though significantly weaker than Earth's. Venus has no magnetic field, but its rotation is also slower than it takes for Venus to go around the Sun.