Are period 5 elements common in most stars?

[Guilherme Franco]

My question might seem simple, however I couldn't find data on this.

Let me explain my situation: I'm involved in a project about the formulation of new criteria to avaliate exoplanetary systems for search of extraterrestrial intelligence.

The key question is mostly around the element Molybdenum. I've seen various books talking about this element's importance for intelligent life, however, I've never seen any of them actually state wether if only some stars have enough Molybdenum or if most stars have it.

Before I go into learning how to work with and fit spectral data from catalogs to detect Molibdenum in stars (I know it's possible because I've found articles of people who used data from such catalogs to detect this particular element), I must check one thing:

Do almost every star (in our galaxy) contain big amounts of period 5 elements (like amounts equal or greater than the ones in our Sun)?

Because this would seriously make all effort futile. Once the idea is to select candidates for the search program, then this criteria should be able to either exclude a great amount of stars or include a small amount. If every star I looked at had considerable amounts of Mo, then this would be futile.

Specially because intelligent life need relatively little Mo to work (the Sun for example is only 0,0000009% Mo and Earths crust is 0.0001% Mo, all of them by mass), and I think that any stars where Mo lines were clearly present would make valid candidates according to this one criteria.

Will there be many stars with Mo amounts much lower than the one found in our Sun?

Thanks!

 

[phyzguy]

Before you embark on this, I think you should examine the evidence that Molybdenum is important for life. The only references I've seen look like creationist nonsense. Do you have any peer-reviewed references that show the importance of Mo in the development of life?

 

[stefan r]

Do almost every star (in our galaxy) contain big amounts of period 5 elements (like amounts equal or greater than the ones in our Sun)?

UniverseAbundance 5 x 10^-7
SolarAbundance. 9 x 10^-7

Some metallic asteroids have high concentrations of rare elements. The composition of a surface may reflect the composition of meteor impacts.

Population 1 stars have more metals than population 2. Population 3 stars have extreme shortages of everything larger than helium.

Some stars have weird compositions. Przybylski's star for example.

Molybdenum is produced by the s-process in stars.

...
Let me explain my situation: I'm involved in a project about the formulation of new criteria to avaliate exoplanetary systems for search of extraterrestrial intelligence.

The key question is mostly around the element Molybdenum. I've seen various books talking about this element's importance for intelligent life, however, I've never seen any of them actually state wether if only some stars have enough Molybdenum or if most stars have it.

...

The population 2 stars are much less likely to have a rocky planet. Stars closer to the galactic core also have more metals than other population 1 stars. Increased frequency of super novas, collisions, and orbital instability have been proposed as harmful to animal life.

Molybdenum is used by eukaryotes (on earth). The lack molybdenum could be a filter. If we limit our "search for life" to "identical to Earth life" then we will only find similar life forms. Evolution of intelligent life might require some hardships. If life is too easy what will drive the evolution of intelligence?

I doubt that Mo enrichment above Earth's abundance would accelerate formation of intelligent life. Some pacific island have shortages of trace elements. Jared Diamond's book "collapse" included lack of trace element dust as a reason some remote island civilizations failed. Island civilizations closer to Asia's dust plume had a much higher survival rate. On an exoplanet other factors may be much larger than the abundance of Molybdenum in the crust. Plate tectonics, volcanic activity, and ocean depths will effect the availability of elements to a surface population. Also life on a planet evolves to match the environment. A molybdenum poor planet will find a different source of nitrogen or use less of it. Polynesian explorers and their plants evolved to live in a environment with excess trace elements.

It would be hard to set a minimum crust abundance of trace elements needed for intelligent life. How much nitrogen would an ediacaran need fixed in order evolve and feed a brain? Excessive growth of protein could have boosted the evolution of tribolites and helped to cause the extinction of ediacarans. Which steps accelerated the timeline toward evolving intelligence and which were set backs? We do not actually know that chordates evolve intelligence faster than ediacarans.

It would be fascinating to look at life on a planet that was like Earth but missing something. It would be a valuable piece of data. We can not currently determine if intelligence evolves within 4+ billion years of life in 1 out of a thousand planets or 1 out of millions/billions. A close look at any alien ecosystem would add a lot of information.

 

[OmCheeto]

Before you embark on this, I think you should examine the evidence that Molybdenum is important for life. The only references I've seen look like creationist nonsense. Do you have any peer-reviewed references that show the importance of Mo in the development of life?

You must have used different keywords in your search. I found the following:

Molybdenum cofactor (Moco) is a metal-containing prosthetic group common to nearly all molybdoenzymes and is ubiquitous to all kingdoms of life.​

My question might seem simple, however I couldn't find data on this.

I'm guessing your question is the title of this thread; "Are period 5 elements common in most stars?"

After an hour of googling, I came across an interesting web site: http://www.nataliehinkel.com/hypatia-catalog.html

The Catalog
The full database can be accessed at www.hypatiacatalog.com.

I study the element abundances in the solar neighborhood, or within 150pc of the Sun. I have put together the largest collection of stellar abundances, called the Hypatia Catalog, for 53 elements within +4,300 main sequence (FGK-type) stars as compiled from literature. Hypatia provides a wealth of chemical abundances and kinematic information which has implications for the evolution of our nearby galaxy, the formation of planetary systems, and astrobiology.​

Natalie appears to have put together a tool which might answer your question(s).

I say "appears" and "might", as I'm not an astrophysicist, and don't understand negative ratios.

 

[stefan r]

The full database can be accessed at www.hypatiacatalog.com.
​

​

You must have used different keywords in your search. I found the following:

Molybdenum cofactor (Moco) is a metal-containing prosthetic group common to nearly all molybdoenzymes and is ubiquitous to all kingdoms of life.​

I suspect molybdenum could be bypassed. Nitrogen fixing can be done by vanadium nitrogenase. Evolution solves many problems. Life can get stuck on one solution to a chemistry problem. For example all fish have vertical tails and all sea mammals have horizontal flukes. Both caudal fins and flukes get the propulsion job done. I do not know how evolving animals would replace Moco but it is hard to believe it is a major obstacle.