After the last collider, there is still UHECR

[Astronuc]

After the last collider has finished, rare, ultra-energetic cosmic rays will continue revealing the Universe’s secrets.
https://bigthink.com/starts-with-a-bang/particle-physics-continue-last-collider/

In May of 2021, the second most energetic cosmic ray ever detected struck Earth, producing a shower of particles detected on the ground by the Telescope Array Collaboration. These particles achieve energies more than a million times greater than the maximum LHC energy, such that after humanity has built our last collider, the energy frontier will still be accessible from space, albeit extremely rarely.

https://en.wikipedia.org/wiki/Ultra-high-energy_cosmic_ray

he first observation of a cosmic ray particle with an energy exceeding 1.0×10²⁰ eV (16 J) was made by John Linsley and Livio Scarsi at the Volcano Ranch experiment in New Mexico in 1962.

https://en.wikipedia.org/wiki/Ultra...ay#Ultra-high-energy_cosmic_ray_observatories

https://en.wikipedia.org/wiki/Oh-My-God_particle

 

[sbrothy]

Good point. I guess that's the closest we'll get to a space-collider in the near future...

 

[mfb]

The LHC detectors start just centimeters away from the collision point (millimeters for LHCb). They can get momentum measurements of all decay products, particle identification, measure decay lengths, and more. They can study once-in-a-trillion collision products because they have quadrillions of collisions.

Cosmic rays don't get you any of that information because your detector is tens of kilometers away and high energy particles are way too rare to look for rare processes. They are interesting to study the universe, but they can't do the job of accelerators.