“It doesn’t alter our theory of what caused the extinction event—but it makes it less likely that sulphur contained in the impactor was the smoking gun,” co-author Philippe Claeys, a planetary scientist and professor at the Free University of Brussels in Belgium, said in a statement. “The fine debris thrown into the atmosphere would have [been] the primary factor.”

https://gizmodo.com/the-asteroid-that-killed-the-dinosaurs-may-not-have-done-it-exactly-how-we-thought-2000787712

How would they distinguish bolide sourced sulphur from the oto 10¹⁴ kg of SO₂ estimated to have been sourced from the extensive anhydrite deposits below Chicxulub?

Ref: Emission spectra of a simulated Chicxulub impact-vapor plume at the Cretaceous–Paleogene boundary

Edited Monday at 08:27 PM4 days by sethoflagos

I would think the impact crater itself would have a massive amount of sulfur, but there would be a thin film deposited all over the world at strata corresponding to 65M years.
Then again Sulfur 'melts at 115^o and burns at 200^o, while its dust is explosive, so what would atmospheric entry have done to this 'sulfur' asteroid if it wasn't mostly rock/metal ?

Wouldn't that amount of energy suddenly introduced into a closed system, cause a catastrophic system failure anyway?

3 hours ago, dimreepr said:

Wouldn't that amount of energy suddenly introduced into a closed system, cause a catastrophic system failure anyway?

What closed system?

20 hours ago, swansont said:

What closed system?

Isn't the Earth, essentially, a closed system?

1 hour ago, dimreepr said:

Isn't the Earth, essentially, a closed system?

No. Matter enters and leaves. Literally tons of space dust enters the earth’s atmosphere every day

https://www.universetoday.com/articles/getting-a-handle-on-how-much-cosmic-dust-hits-earth

But you said introduction of energy, and the relevant term would be isolated system, and it’s definitely not that.

32 minutes ago, swansont said:

No. Matter enters and leaves. Literally tons of space dust enters the earth’s atmosphere every day

https://www.universetoday.com/articles/getting-a-handle-on-how-much-cosmic-dust-hits-earth

But you said introduction of energy, and the relevant term would be isolated system, and it’s definitely not that.

You're the expert...

19 minutes ago, dimreepr said:

You're the expert...

You don't need to be an expert to understand that the impact wasn't powerful enough have a very big effect on the larger body of the Earth (as a body) , although the effect on life more generally was obviously immense.

The evidence for this is that the Earth was not shifted appreciably from its orbit, its spin was almost unaffected, it did not flip or shift spin axis appreciably.

It should also be noted that, although by far the largest factor in the extinction, there was also an accumulation over time of other important factors, unrelated to the impact.

The fine particulates theory has been a strong contender for quite some time, so maybe not as fresh as the article makes it sound. I was reading about dust-blocking asteroid winters back when Sagan et al had published their famous TTAPS paper (1983) on the mechanism of a potential nuclear winter, with parallels being drawn between the two.

On 7/20/2026 at 2:25 PM, sethoflagos said:

How would they distinguish bolide sourced sulphur from the oto 10¹⁴ kg of SO₂ estimated to have been sourced from the extensive anhydrite deposits below Chicxulub?

The OP paper said something about SO3 predominant. Let me look...

Recent laboratory experiments suggest that volatized sulfur was dominated by sulfur trioxide (SO3) not SO2

If so, then far less radiation blocking by SO3 than SO2.

SO2 is a relatively stable gas in the upper atmosphere. It persists long enough to disperse globally and acts as a precursor, reacting with water to form highly reflective sulfuric acid aerosols. But SO3 is highly reactive in the stratosphere, it reacts with water vapor almost immediately to form sulfuric acid, which limits its ability to spread evenly. Also, when exposed to solar radiation, certain byproducts of SO3 can break down, also cutting reflective effect.

Edited Wednesday at 02:14 PM2 days by TheVat
fjsrglogglty

19 minutes ago, studiot said:

You don't need to be an expert to understand that the impact wasn't powerful enough have a very big effect on the larger body of the Earth (as a body) , although the effect on life more generally was obviously immense.

The evidence for this is that the Earth was not shifted appreciably from its orbit, its spin was almost unaffected, it did not flip or shift spin axis appreciably.

I once worked out that it was the geometric equivalent of my house being hit by a dried pea. Helped me get my head around the scaling.

14 minutes ago, TheVat said:

The OP paper said something about SO3 predominant. Let me look...

I saw that. The thing is, the thermal shock of impact would have exceeded that needed to strip the oxygen from both SO_x, at least to SO, so I don't see how the dioxide/trioxide split could be diagnostic.

Edited Wednesday at 02:37 PM2 days by sethoflagos

21 hours ago, studiot said:

You don't need to be an expert to understand that the impact wasn't powerful enough have a very big effect on the larger body of the Earth (as a body) , although the effect on life more generally was obviously immense.

You may not, but if memory serves didn't the impact cause immense volcanic disruption on the opposite side of the world?

1 hour ago, dimreepr said:

You may not, but if memory serves didn't the impact cause immense volcanic disruption on the opposite side of the world?

I hoped I had provided enough information to explain what I meant about the effect of the impact.

If you want more detail please say and I will be happy to oblige.

As regards vulcanism, this was nothing new at that time. The Deccan traps eruptions started before Chicxulub and lasted three quarters of a million years, whilst the impact lasted a few hours.

Yes I think the Deccan was the second largest known system of volcanic eruptions, the largest being the Siberian traps nearly 200 million years earlier, which last a couple of million years.

But also I expect you are aware that human seismology detects activity, on the other side of the world, even from human sized explosions.

https://www.science.org/doi/10.1126/science.aau2422

22 hours ago, studiot said:

I hoped I had provided enough information to explain what I meant about the effect of the impact.

You all have, another gap in my understanding filled, thanks.