Possible exposure of Earth to dense interstellar medium 2-3M years ago
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Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#2The geologic time record shows a pretty noticeable drop in this time frame, before the glacial period started & temperatures started swinging up & down. https://en.wikipedia.org/wiki/Geologic_temperature_record#Ov...
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#3The geologic time record shows a pretty noticeable drop in this time frame, before the glacial period started & temperatures started swinging up & down. https://en.wikipedia.org/wiki/Geologic_temperature_record#Ov...
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Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#4Very interesting paper! Proposes (with lower bound of 1.3% chance) that the solar system may have passed through a local interstellar cloud, which would have caused the heliosphere to shrink to smaller than the orbit of the earth (0.22 au) some 2-3 mya. This may have affected the Earth's atmosphere and climate. Scroll down for some cool illustrations of a simulation showing how the heliosphere would have been tiny with an elongated tail in a denser interstellar medium. There's also a map showing the interstellar cloud relative to the trajectory of the solar system.
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#5Are there fossil records that correspond to higher levels of dense interstellar medium radiation 2-3M years ago?
Punctuated equilibrium: https://en.wikipedia.org/wiki/Punctuated_equilibrium
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#6Every square meter of a space ship passing through this at the speed of light would interact with ~3e13 hydrogen atoms per second.
I don't know if I did this correctly but that's only ~27kJ per second of mass energy. I thought it would be a lot more.
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#7Are we able to determine if other star systems have experienced the same type of encounter? (Not statistically, I mean detection or instrument based)
I'm assuming it's either difficult or impossible to measure another star's heliopause. It would be fascinating to see the effects of a cold cloud interaction in "real" time!
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#8Presumably it has happened before in the history of the earth but it would be interesting to know what effects it had on life on earth and, by extension, the arrival and development of modern humans.
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#9Presumably it has happened before in the history of the earth but it would be interesting to know what effects it had on life on earth and, by extension, the arrival and development of modern humans.
Before the history of the earth?
Re: Possible exposure of Earth to dense interstellar medium 2-3M years ago
#10Why does this make me feel a little dirty and exposed?
Like, who knows what kinda alien DNA strands or spores are carried by the ISM?!
I wonder if it would be possible to track biodiversity increases caused by the transit? Assuming there is biological material in the ISM, perhaps some of it made it into our biosphere!
Very fun!