Earth is outside most likely life region of galaxy

News about space exploration and scientific advancements. What do you find interesting?

Moderators: SDS Members, SDS Owner

Forum rules
The forum is intended only for space and science information. Discussions about how it applies to Starfire is encouraged - there might be some great ideas we can use!

1. Nothing obscene.
2. No advertising or spamming.
3. No personal information. Mostly aimed at the posting of OTHER people's information.
4. No flame wars. We encourage debate, but it becomes a flame when insults fly and tempers flare.

Earth is outside most likely life region of galaxy

Postby southwestforests on Mon 18 Jan 2021 21:27

Hmm. Okay, so what does it mean when the only known occurrence of a thing is not within the most likely range of parameters for it to occur?

Computer Model Predicts When and Where Extraterrestrial Life Is Most Likely to Emerge in Our Galaxy (Spoiler: It's Not Here)
Earth sits outside the region of the Milky Way where life is most likely to have arisen, say astronomers.
The Physics arXiv Blog December 29, 2020 5:00 PM

https://www.discovermagazine.com/the-sc ... ost-likely

But there is another set of factors that also determine the likelihood of life and these have been less well investigated. Back in 1983, the Soviet astronomers Leonid Marochnik and Lev Mukhin suggested that technological civilizations might be most likely to emerge in a “belt of life” around the center of our galaxy.

Other astronomers have since toyed with the idea of a “galactic habitable zone” where conditions are ripe for the emergence of life. This region is essentially a donut-shaped zone around the center of the galaxy, where life appears more likely to emerge. But just how this likelihood changes over time has yet to be explored.

Now that changes, thanks to the work of Jonathan Jiang at NASA’s Jet Propulsion Laboratory in Pasadena working with a couple of colleagues. This team has created a three-dimensional model of the galaxy that simulates the likelihood that life might emerge on Earth-like planets and suggests regions of the galaxy where life seems most likely to have arisen.
Screw the rivets, I build models for atmosphere, not detail
User avatar
southwestforests
Captain
Captain
 
Posts: 214
Joined: Mon 27 Aug 2012 21:01
Location: Boonville, Missouri - a little antebellum burg on the Missouri River

Re: Earth is outside most likely life region of galaxy

Postby krenshala on Sat 23 Jan 2021 14:21

To my mind, either the model is flawed, or the inputs to the model have issues (most likely due to insufficient data being available to us). A good enough model, with the correct/accurate data inputs should always have results that match reality (within whatever its error bars are) when given starting parameters that match reality.
-- krenshala
None survive the harvest!

Yeah, I'm finally back (again)! Sometimes, life (and 13yo son's) don't leave you time to play SF and earn a paycheck. :/

No, really! Matt actually made me an admin here!
krenshala
SDS Member
SDS Member
 
Posts: 2931
Joined: Thu 02 Jul 2009 17:13
Location: Austin TX, NorAm, Sol III

Re: Earth is outside most likely life region of galaxy

Postby aramis on Sat 26 Mar 2022 16:31

krenshala wrote:To my mind, either the model is flawed, or the inputs to the model have issues (most likely due to insufficient data being available to us). A good enough model, with the correct/accurate data inputs should always have results that match reality (within whatever its error bars are) when given starting parameters that match reality.

The default assumption that Earth is typical may be utter bollocks.
the Sol system is very much not typical.

The modal star is class m. the modal planet found is a super earth. the modal found GG is a hot jovian.

only some of those can be discounted as sampling issues.

thatstar detection is biased towards large stars means the dominance of small M_V means they are over-represented. (That types N and S were originally scheduled to be sub-M9v stars... but they coukdn't find them... and so the N and S codes got reassigned to other, special cases... and then we started discovering lots of sub-M9v stars... so they got high numbers... to m`5... then redefined with L, T, and Y.... (Y technically aren't. stars, nor are some T's...)

Hot Jovians are easier to detect than cold...
Superterrestrial worlds are easier to detect than smaller ones... but we lack both a hot gas giant annd a superterrrestrial...
aramis
Rear Admiral
Rear Admiral
 
Posts: 354
Joined: Mon 01 Mar 2010 00:42
Location: Eagle River, Alaska

Re: Earth is outside most likely life region of galaxy

Postby Cralis on Thu 31 Mar 2022 21:35

First, it should be noted that we've found what? 5000 planets? or something like that? So planets aren't exactly rare.

So then I would posit that our sample size is ridiculously and statistically insignificant.... aka too small ...to form any kind of model and expect it to be realistic.
Image
User avatar
Cralis
SDS Member
SDS Member
 
Posts: 11841
Joined: Tue 30 Jun 2009 19:27
Location: Oregon, USA

Re: Earth is outside most likely life region of galaxy

Postby aramis on Fri 01 Apr 2022 02:57

as of right now, 5009 confirmed, 8738 more not confirmed.
https://exoplanets.nasa.gov/

So, over 13k.

When I was running the numbers for stars back in 2012, I ran the numbers for stars based upon number in detection range volume for that size star. That gives as fair a system as one can in a sample that's size:range biased.
That was before the real awareness of a bunch of rogue planets, too.

Of those, 70 exos or candidates are rogue...

https://www.newsweek.com/astronomers-70 ... h%20worlds.
aramis
Rear Admiral
Rear Admiral
 
Posts: 354
Joined: Mon 01 Mar 2010 00:42
Location: Eagle River, Alaska

Re: Earth is outside most likely life region of galaxy

Postby Cralis on Tue 05 Apr 2022 19:34

Wow, I haven't been paying enough attention...
Image
User avatar
Cralis
SDS Member
SDS Member
 
Posts: 11841
Joined: Tue 30 Jun 2009 19:27
Location: Oregon, USA


Return to Space and Science

Who is online

Users browsing this forum: No registered users and 4 guests