# What is the most massive element that we observe in nature? **URL:** \ **Category:** Factual Questions\ **Created:** [December 8, 2008, 5:56pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274 "2008-12-08T17:56:53Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 8, 2008, 5:56pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/1 "2008-12-08T17:56:53Z")
I was just reading in wikipedia that we see californium in the spectra of supernovae. Do we see heavier stuff as well? Thanks, Rob ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [December 8, 2008, 7:32pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/2 "2008-12-08T19:32:54Z")
Aha! That might explain the creation of Planet Hollywood. ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 9, 2008, 1:37pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/3 "2008-12-09T13:37:53Z")
Gee, I thought this question would have been right up some dopers’ alley. Let’s see if a little bump works. Thanks, Rob ---
**Author:** ![flight](https://avatars.discourse-cdn.com/v4/letter/f/bbce88/32.png) [@flight](https://boards.straightdope.com/u/flight)\ **Post date:** [December 9, 2008, 7:01pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/4 "2008-12-09T19:01:28Z")
> [@cmyk](#): > > Aha! That might explain the creation of Planet Hollywood. I love you. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [December 9, 2008, 7:10pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/5 "2008-12-09T19:10:18Z")
I’d suggest that what we have here is two questions: 1 - What is the highest element creatable by nature? 2 - Have we looked for it and if so, have we found it? I recall reading that we have found the remains of transuranic elements - namely the decayed products - but cannot recall the cite. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [December 9, 2008, 7:13pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/6 "2008-12-09T19:13:41Z")
Depending on what you want to define as an ‘element’, Neutronium (what neutron stars are made from) is the densest we’ve ever observed. (It would, incidentally, sit on the periodic table at position zero, as it has no protons (or electrons, for that (degenerate) matter).) If you don’t like anything you can’t even contemplate making compounds of being called an element, then I think one natural reactor in Africa made substantial amounts of Plutonium out of Uranium well before most life as we know it even existed. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [December 9, 2008, 10:32pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/7 "2008-12-09T22:32:59Z")
Well, if you put it that way, surely the densest is whatever’s inside a singularity. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [December 10, 2008, 5:04am UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/8 "2008-12-10T05:04:28Z")
> [@Quartz](#): > > Well, if you put it that way, surely the densest is whatever’s inside a singularity. Inside a singularity physics as we know it breaks down. Neutronium is the best we’ll do with the knowledge we have. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [December 10, 2008, 6:05am UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/9 "2008-12-10T06:05:33Z")
He asked what’s observable - I don’t think neutronium exactly counts. According to Wikipedia’s article on supernova nucleosynthesis: > [@](#): > > Due to the large amounts of energy released in a supernova explosion, much higher temperatures are reached than stellar temperatures. Higher temperatures allow for an environment where elements up to the atomic mass of 254 are formed, **californium being the heaviest known** … Unfortunately, they don’t give a reference for that statement, but I suspect it’s D. D. Clayton, “Handbook of Isotopes in the Cosmos” 2003, the only recent reference given for the article. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [December 10, 2008, 7:16am UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/10 "2008-12-10T07:16:21Z")
**Nametag** : Neutron stars have to be made of something, no? I suppose there are varying degrees of observability: We can’t observe the backs of our own heads directly. Maybe it’ll be easier if we ignore degenerate matter, but that ignores a good deal of the wonder of the Universe as far as I’m concerned. It’s up to the OP. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [December 10, 2008, 10:01am UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/11 "2008-12-10T10:01:50Z")
> [@Derleth](#): > > **Nametag** : Neutron stars have to be made of something, no? Yes, but not 100% pure neutrons. Go read the Wiki [Neutron Star](http://en.wikipedia.org/wiki/Neutron_star) article for more. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [December 10, 2008, 10:16am UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/12 "2008-12-10T10:16:42Z")
> [@dtilque](#): > > Yes, but not 100% pure neutrons. Go read the Wiki [Neutron Star](http://en.wikipedia.org/wiki/Neutron_star) article for more. Ah, OK. I thought the matter was a lot closer to being settled than that. I suppose if we wanted to propose ultradense ultratheoretical matter that isn’t a mere singularity, we’d be talking about preon-degenerate matter. Since it seems that preons (no relation to the degenerate proteins called ‘prions’) might not actually exist, though, that would just be silly. ---
**Author:** ![sweeteviljesus](https://avatars.discourse-cdn.com/v4/letter/s/898d66/32.png) [@sweeteviljesus](https://boards.straightdope.com/u/sweeteviljesus)\ **Post date:** [December 10, 2008, 2:16pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/13 "2008-12-10T14:16:54Z")
I wasn’t referring to density. I was referring to atomic mass. And I guess that Cf is the answer according to the above post, unless someone can cite something higher on the periodic table. (I seem to remember reading one time that you could think of a neutron star as a single nucleus and as such, that would be the most massive element found in nature, but I may not be recalling that correctly.) If Cf, is indeed the most massive element observed, does that mean that there are no “islands of stability” in transuranic elements or that supernovae don’t have the requisite energy to create them? Thanks for your help, Rob ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [December 10, 2008, 9:19pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/14 "2008-12-10T21:19:25Z")
How dense would a quantity of superheavy element eka-thorium be? AKA unbibium? > **[Unbibium](https://en.wikipedia.org/wiki/Unbibium)** > > Unbibium, also known as element 122 or eka-thorium, is the hypothetical chemical element in the periodic table with the placeholder symbol of Ubb and atomic number 122. Unbibium and Ubb are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table of the elements, it is expected to follow unbiunium as the second element of the superactinides and the fourth element of the 8th... ---
**Author:** ![Simplicio](https://avatars.discourse-cdn.com/v4/letter/s/c37758/32.png) [@Simplicio](https://boards.straightdope.com/u/Simplicio)\ **Post date:** [December 10, 2008, 11:14pm UTC](https://boards.straightdope.com/t/what-is-the-most-massive-element-that-we-observe-in-nature/476274/15 "2008-12-10T23:14:33Z")
> [@sweeteviljesus](#): > > (I seem to remember reading one time that you could think of a neutron star as a single nucleus and as such, that would be the most massive element found in nature, but I may not be recalling that correctly.) I think most people would consider an element to be bound by the strong nuclear force. Since neutron stars are bound by gravity, I’d say that discounts them.