Physicists: Ancient life might have escaped Earth and journeyed to alien stars

Jan 16, 2020
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If this transfer of Earthborn life to a comet could happen, then it would seem to be as likely that the reverse could be true. A comet grazing our atmosphere could deposit life from another world.
 
Feb 2, 2020
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It's not really a new theory, it's basically Fred Hoyle's Panspermia theory from the 1970s.
One interesting thought that would explain why we have never detected alien life would be that it originated on Earth. Perhaps very unlikely, but possible.
 
Feb 2, 2020
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my problem with this article is that i dont fill that enough time could have passed for a comet to arrive at another system and live evolve maybe in the future but not yet. i mean how fast would a comet have to be going to get to the nearest star anyway. plus it has to get thrown out of the system first not that it couldnt happen but. more likely it happened here than us someplace else.
 

dan

Feb 3, 2020
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my problem with this article is that i dont fill that enough time could have passed for a comet to arrive at another system and live evolve maybe in the future but not yet. i mean how fast would a comet have to be going to get to the nearest star anyway. plus it has to get thrown out of the system first not that it couldnt happen but. more likely it happened here than us someplace else.
Spell check please" survey says,
 
Apr 17, 2020
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In reply to "I mean how fast would a comet have to be going to get to the nearest star anyway?"

Comet speeds
There are relatively big varieties, but most of them is between 10 and 70 km/s. If a comet is a periodic comet, that means it needs to have an elliptic orbit around the Sun. That gives an upper limit to its speed of the escape speed from the solar system on the orbit of the Earth. That is around 40 km/s.

This is taking the fastest speed beyond which the comet would leave the Solar System.
Being near the Sun the comet would be travelling near its fastest.

At this speed I make it 4.367 / 0.133 years approx. 32.8 years to get to alpha Centauri.

I suspect my math might need rechecking, but Ihave taken fastest speeds throughout the calculation so it would be erring on the top side giving the shortest journey time.
 
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