Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

New findings point to an Earth-like environment on ancient Mars

discover.lanl.gov

Post reply on HN
Print view View original

191–200 of 329 posts

Re: New findings point to an Earth-like environment on ancient Mars

#191

Post by Tuna-Fish »

adastra22 wrote: post #108
Tuna-Fish wrote: post #90

Earlier quoted context omitted.

> as the Sun cooled Huh? The Sun has consistently gotten hotter with age.

Thank you for the factual correction. It’s the geothermal (aerothermal?) heat that has decreased by more than the sun’s increasing luminosity, resulting in net temperature loss.

That's wrong too. While geothermal heat is going down, it's doing it very slowly and has very little impact on surface temperature. Earth was on average significantly colder in the past, to the point of there being several "snowball earth" episodes when the entire surface froze over. That's no longer possible, strictly because the Sun is warmer now.

Mars was somewhat warmer before, but that was not because of geothermal, but because it used to have a thicker atmosphere, and that retained heat better.

Re: New findings point to an Earth-like environment on ancient Mars

#192

Post by elorant »

xyst wrote: post #189
elorant wrote: post #175

This is scary on two fronts. One, whatever happened to Mars could happen to Earth, and two, it puts the Great Filter probably in our future. If our solar system had two hospitable planets then there should be plenty of Earth like planets around in our galaxy. In which case we end up with the Fermi Paradox. If life is so abundant in the Universe how come we haven’t been in contact with aliens?

That’s easy. Earthling tech is just too behind the curve and society is stuck in a state where we are considered primitive.

We could locate technosignatures though. Even if they don't wish to contact us we could tell if the galaxy was teeming with intelligent life.

Re: New findings point to an Earth-like environment on ancient Mars

#193

Post by obfuscator »

dylan604 wrote: post #170
walterbell wrote: post #65

Kurd Lasswitz wrote "Two Planets" in 1897, https://news.ycombinator.com/item?id=39598983 > Lasswitz's Martians differ little from man physically, but ethically, intellectually, scientifically, and socially they are the prototype of the ideal human being. They seek to educate man, asking in return only air and energy to supplement the diminished supplies in their own, older world. The story revolves around a group of…

> "They are already here among us – they just call themselves Hungarians." Do Germans also have jokes like "how many Hungarians does it take to screw in a light bulb"?

Those exist here at the expense of different peoples, depending where you are in Germany. Most popular, from what I can tell, are East Frisians, but that has to do with a comedian who made a lot of those jokes (Otto Waalkes).

Re: New findings point to an Earth-like environment on ancient Mars

#194

Post by octopoc »

vkou wrote: post #155
pdonis wrote: post #111

Earlier quoted context omitted.

> I'm not familiar with the extent of his crimes, if any. He was the Nazis' best rocket engineer, responsible for, among other things, the V2s that devastated much of London. By the standards of the Nuremberg trials, he probably should have been tried and convicted. But he was never even accused, because the US wanted his rocket expertise--by the time of the Nuremberg trials, he was already working for the US Army.

The damage the V2s inflicted on London paled in comparison to the destruction of continental European and Russian and Japanese cities. The V2 killed more (enslaved) people who were building it than it did in its attacks. It was only 'successful' as a propaganda weapon. ...And by the standards of the Nuremberg trials, the heads of every allied airforce, and all of their immediate subordinates and sub-subordinates shou…

> And by the standards of the Nuremberg trials, the heads of every allied airforce, and all of their immediate subordinates and sub-subordinates should have been dancing the hemp fandango.

That's a very good point, although the Nuremberg trials used torture to get confessions, so literally anybody could have been convicted.

Re: New findings point to an Earth-like environment on ancient Mars

#195

Post by airstrike »

gadflyinyoureye wrote: post #44
tokai wrote: post #11

Earlier quoted context omitted.

I don't remember where I read it, but somebody wrote that a geologist with a hammer could do more science in an afternoon than all our mars probes have done combined. Its hard to do science with a rc car, even if said car is cutting edge.

That’s true. Look at how many time SG-1 got into an issue even with the MALP. That’s with a much quicker wireless connection too.

Sounds like a great opportunity to rewatch one of my all time favorite episodes, "Revisions" (s07e05)

Re: New findings point to an Earth-like environment on ancient Mars

#198

Post by Qem »

jovial_cavalier wrote: post #85
adastra22 wrote: post #27

Earlier quoted context omitted.

You jest, but I seriously believe we are likely martians. Early panspermia from Mars settles a LOT of astrobiological questions about origin of life and LUCA complexity. To be clear, Mars’ descent into inhospitality was totally natural and the result of a smaller planet with stripped atmosphere just outside the habitable zone as the Sun cooled. I doubt Martian life developed to be multicellular. But I bet when we go…

What is your actual mechanism for life getting to Earth from Mars?

Early solar system had plenty of impact events happening. Mars has less gravity than Earth, so it's easier to eject material from there. Picture a comet or asteroid hitting early mars. Most ejecta falls back to Mars, but still tens of thousands of rock fragments are ejected into space, in random directions. Some fraction of them are likely to reach Earth a few years later, potentially carrying any microbial stowaways present in Mars by then.

Re: New findings point to an Earth-like environment on ancient Mars

#199

Post by aeonik »

Tuna-Fish wrote: post #191
adastra22 wrote: post #108

Earlier quoted context omitted.

Thank you for the factual correction. It’s the geothermal (aerothermal?) heat that has decreased by more than the sun’s increasing luminosity, resulting in net temperature loss.

That's wrong too. While geothermal heat is going down, it's doing it very slowly and has very little impact on surface temperature. Earth was on average significantly colder in the past, to the point of there being several "snowball earth" episodes when the entire surface froze over. That's no longer possible, strictly because the Sun is warmer now. Mars was somewhat warmer before, but that was not because of geother…

What? I thought the geologic record showed that it's been hot most of the time, punctuated by a few ice ages.

https://en.m.wikipedia.org/wiki/Geologic_temperature_record#...

Post reply on HN