Enceladus

[billy rubin]

you can call me gringo though

everybody else does

whether i step on my dick or not

[Recusant]

Meanwhile, back at the icy moon . . .

"If We Find Life on Europa or Enceladus, It Will Probably Be a '2nd Genesis'" | Space.com

An up-close look at the "tiger stripes" on Saturn's moon Enceladus, which
is thought to harbor a big ocean of liquid water beneath its icy surface.
Image Credit: NASA, ESA, JPL, SSI, Cassini Imaging Team

If there are creatures swimming in the buried oceans of the outer solar system, they're probably not related to us, new research suggests.

Some scientists believe that life has hopped from world to world around the solar system, aboard chunks of rock blasted into space by comet or asteroid impacts. Indeed, there's a school of thought that the life teeming here on Earth is actually native to Mars, which likely boasted habitable conditions earlier than our own planet did. (This rock-riding idea is known as "lithopanspermia," a subset of the broader panspermia notion, which envisions spread by whatever means, either natural or guided by an intelligent hand.)

But what are the odds that such putative pioneers could colonize the habitable real estate much farther out — specifically, the Jupiter moon Europa and the Saturn satellite Enceladus, both of which harbor big oceans of salty liquid water beneath their ice shells?

Purdue University geophysicist Jay Melosh tackled this question and presented the results last week during a talk here at the annual fall meeting of the American Geophysical Union.

Melosh used computer models to follow the fates of 100,000 simulated Mars particles launched off the Red Planet by an impact. He modeled three different ejection speeds: 1, 3, and 5 kilometers per second (about 2,240 mph, 6,710 mph and and 11,180 mph, respectively).

In the simulations, a tiny percentage of the particles ended up hitting Enceladus over the course of 4.5 billion years — just 0.0000002% to 0.0000004% of the number that impacted Earth. The numbers were about 100 times higher for Europa; that moon got 0.00004% to 0.00007% of Earth's particle share.

[. . .]

These results might seem to bode well for life's spread; after all, it might take just one impact of a microbe-bearing rock to turn Europa or Enceladus from habitable to inhabited. But there are more factors to consider, and they tamp down the optimism.

For example, Melosh found that the median transit time for a Mars meteorite that ends up hitting Enceladus is 2 billion years. Microbes are tough, but that's a long time to endure the harsh conditions of deep space. And the simulations indicated that these incoming Mars rocks would hit Enceladus at between 5 and 31 km/s (11,180 mph to 69,350 mph). The lower end of that range might be survivable, but it's hard to imagine anything living through those more extreme impacts, Melosh said.

"So, the bottom line: If life should be found in the oceans of Europa or Enceladus, it is very likely that it's indigenous rather than seeded from Earth, Mars or (especially) another solar system," Melosh said during his AGU talk. (His calculations peg the probability of an exoplanet meteorite impacting Earth over the past 4.5 billion years at just 0.01%. The chances are much lower for Europa and Enceladus, he said.)

[Continues . . .]

[Magdalena]

Meanwhile, back at the icy moon . . .

Yeah, guys, come on pay attention.

No more enchiladas or Micheladas. (Those are good, though.    )

Sorry, please, continue.

[Recusant]

It wasn't meant as any sort of harrumphing. As I've said before, I'm happy for people to use any thread that I start for whatever they like, within the rules of this site. This certainly isn't a classroom, and I'm not expecting serious responses, though they're welcome. I was merely posting another item about Enceladus. Carry on. 

[Magdalena]

It wasn't meant as any sort of harrumphing. As I've said before, I'm happy for people to use any thread that I start for whatever they like, within the rules of this site. This certainly isn't a classroom, and I'm not expecting serious responses, though they're welcome. I was merely posting another item about Enceladus. Carry on. 

I know.

These guys are funny.

Come on guys, stick to the rules of the site.

[billy rubin]

there are rulez?