by apodman » Fri Jul 25, 2008 7:43 pm
According to
NASA/Spitzer ...
"Spitzer is particularly adept at observing [PAHs], which are useful indicators of organic chemistry and the possibilities for life throughout the universe."
and
"To an astronomer, PAHs are powerful tools for exploring the building blocks necessary for the origins of life in the stars and galaxies beyond the Earth."
and
"PAHs provide a useful probe into such regions, and provide clues to the abundance of potentially life-bearing chemicals."
So it appears that the presence of PAHs is taken to be a good sign for the possibility of life.
However, according to
APOD ...
"PAHs are likely destroyed ... by energetic radiation in intense star forming regions."
So if I want life around my star, do I want it to be formed somewhere other than an "intense" star forming region?
If I want life around my star that was formed in an "intense" star forming region, how long do I have to wait after the radiation dies down for the galaxy's dust clouds to drift by and seed my system with organic molecules?
It appears to me they're not saying that PAHs are building blocks of life, but that they're an indicator that useful organic building blocks might be nearby. And I'm taking the leap of concluding that if the radiation destroys PAHs, it will do the same for other organic componds.
---
Hello emc and bystander,
Thanks for asking, answering, and providing the example for linking to a post. I wanted to know but didn't want to ask. You can also constuct the link manually (the hard way) if you have the post number - which you can get by viewing the html source code, finding the post, and looking for the <a name="nnnnn"> tag. Substitute the actual "nnnnn" digits (twice) in a link of the following form:
http://asterisk.apod.com/vie ... 5869#95869
(The "95869" in the example above is the number for
this post.)
Whoops! The question and answer to which I refer are in another topic and so I will duplicate them here:
bystander wrote:emc wrote:How did you link to RJN's post?
- Go to Asterisk Search.
Type in the desired username in Search for Author:.
Limit the search by Category, Forum, Keywords, etc.
Click Display results as: Posts.
Start your search,
Select the appropriate post and
Copy the shortcut.
According to [url=http://www.spitzer.caltech.edu/features/articles/20050627.shtml]NASA/Spitzer[/url] ...
"Spitzer is particularly adept at observing [PAHs], which are useful indicators of organic chemistry and the possibilities for life throughout the universe."
and
"To an astronomer, PAHs are powerful tools for exploring the building blocks necessary for the origins of life in the stars and galaxies beyond the Earth."
and
"PAHs provide a useful probe into such regions, and provide clues to the abundance of potentially life-bearing chemicals."
So it appears that the presence of PAHs is taken to be a good sign for the possibility of life.
However, according to [url=http://apod.nasa.gov/apod/ap080725.html]APOD[/url] ...
"PAHs are likely destroyed ... by energetic radiation in intense star forming regions."
So if I want life around my star, do I want it to be formed somewhere other than an "intense" star forming region?
If I want life around my star that was formed in an "intense" star forming region, how long do I have to wait after the radiation dies down for the galaxy's dust clouds to drift by and seed my system with organic molecules?
It appears to me they're not saying that PAHs are building blocks of life, but that they're an indicator that useful organic building blocks might be nearby. And I'm taking the leap of concluding that if the radiation destroys PAHs, it will do the same for other organic componds.
---
Hello emc and bystander,
Thanks for asking, answering, and providing the example for linking to a post. I wanted to know but didn't want to ask. You can also constuct the link manually (the hard way) if you have the post number - which you can get by viewing the html source code, finding the post, and looking for the <a name="nnnnn"> tag. Substitute the actual "nnnnn" digits (twice) in a link of the following form:
http://asterisk.apod.com/viewtopic.php?p=95869#95869
(The "95869" in the example above is the number for [i]this[/i] post.)
Whoops! The question and answer to which I refer are in another topic and so I will duplicate them here:
[quote="bystander"][quote="emc"]How did you link to RJN's post?[/quote][list]Go to [url=http://asterisk.apod.com/search.php]Asterisk Search[/url].
Type in the desired username in [b][i]Search for Author:[/i][/b].
Limit the search by [b][i]Category, Forum, Keywords[/i][/b], etc.
Click [b][i]Display results as: Posts[/i][/b].
Start your search,
Select the appropriate post and
Copy the shortcut.[/list][/quote]