this post was submitted on 08 Jul 2026
11 points (100.0% liked)

Ask Science

17076 readers
14 users here now

Ask a science question, get a science answer.


Community Rules


Rule 1: Be respectful and inclusive.Treat others with respect, and maintain a positive atmosphere.


Rule 2: No harassment, hate speech, bigotry, or trolling.Avoid any form of harassment, hate speech, bigotry, or offensive behavior.


Rule 3: Engage in constructive discussions.Contribute to meaningful and constructive discussions that enhance scientific understanding.


Rule 4: No AI-generated answers.Strictly prohibit the use of AI-generated answers. Providing answers generated by AI systems is not allowed and may result in a ban.


Rule 5: Follow guidelines and moderators' instructions.Adhere to community guidelines and comply with instructions given by moderators.


Rule 6: Use appropriate language and tone.Communicate using suitable language and maintain a professional and respectful tone.


Rule 7: Report violations.Report any violations of the community rules to the moderators for appropriate action.


Rule 8: Foster a continuous learning environment.Encourage a continuous learning environment where members can share knowledge and engage in scientific discussions.


Rule 9: Source required for answers.Provide credible sources for answers. Failure to include a source may result in the removal of the answer to ensure information reliability.


By adhering to these rules, we create a welcoming and informative environment where science-related questions receive accurate and credible answers. Thank you for your cooperation in making the Ask Science community a valuable resource for scientific knowledge.

We retain the discretion to modify the rules as we deem necessary.


founded 3 years ago
MODERATORS
 

Title worded awkwardly, but I was thinking about the chemical makeup of our planet, and the other bodies in our solar system. Is the chemical makeup of our star system similar to every other star system? And if not, are we more similar to stars nearest to ours? Is it totally random? Like does every star system have roughly the same amount of iron, hydrogen, oxygen, etc. When averaged out? Has this even been studied?

you are viewing a single comment's thread
view the rest of the comments

This is a difficult thing to accurately assess. While we can use spectrometry to find chemical compositions of stars and nebulae and planet atmospheres/surfaces, we cant even be certain about the interior of planets and moons within our own solar system, much less the galaxy.

We can make educated guesses based on the mass/volume and the stability of elements but I don't think it’s an exact science.

However, i would imagine the answer to your question is No, the galaxy is not homogeneous. My reasoning is that near the center of our galaxy, stars are much closer together. This not only makes stellar collisions more likely to occur, but also means there will be significantly more cosmic rays in that space than out here near the rim.

Both cosmic rays and stellar collisions are the (theoretical) primary sources of certain elements. Berylium and Boron are created by cosmic rays fission, and as such id expect their concentrations to be higher in denser star clusters. And I’d expect higher concentrations of heavier elements due to both increased collisions AND due to the decay chains of unstable isotopes created by cosmic ray fission.

Cosmic rays are responsible for producing common isotopes like Carbon-14 here on earth, and we live in a pretty empty part of space near a relatively inactive star. So I’d imagine the amount of radioactive isotopes of all kinds would generally be higher in more dense stellar regions too.

All that being said, the most common elements will probably be the same. Hydrogen and helium are the most common in the entire universe, and many light elements like Oxygen and Carbon and even Iron which can be produced by fusion will probably be higher in concentration than any heavier elements regardless of where you are in the universe.