Archive · 15 Sep 2026
CERN Experiment Recreates Cosmic Ray Collisions in Earth’s Atmosphere
Scientists used CERN’s Large Hadron Collider to copy what happens when space particles hit Earth’s air.
They made oxygen beams collide with proton beams in a controlled experiment.
These collisions can help explain how cosmic rays create showers of particles in the atmosphere.
Such particle showers are connected to effects including the Northern Lights.
Before this, scientists mostly used computer programs to predict the collisions.
Those programs sometimes produced different answers.
The researchers took millions of detailed pictures of the collision results.
Their findings should help scientists better understand particles arriving from the Sun and exploding stars.
The ATLAS Collaboration recreated high-energy cosmic ray interactions with atmospheric gases at CERN’s Large Hadron Collider.
Researchers collided oxygen beams with proton beams to simulate particles entering Earth’s atmosphere.
The experiment produced the first laboratory measurements of these cosmic-ray atmospheric collisions, according to the researchers.
A 100-million-pixel camera recorded millions of collision outcomes to measure particle numbers, energies, and angles.
Published in Physical Review Letters, the results indicate that earlier models of these interactions were significantly inaccurate.
- Who
- The international ATLAS Collaboration, including researchers led by Jesse Liu, conducted the study.
- What
- Researchers recreated high-energy cosmic ray collisions with atmospheric oxygen by colliding oxygen and proton beams.
- When
- The timing of the experiment is not specified; the results were reported in Physical Review Letters.
- Where
- At CERN’s Large Hadron Collider.
- Why
- To improve understanding of cosmic-ray interactions, atmospheric particle showers, and the origins of cosmic particles.
- Research group
- ATLAS Collaboration
- Facility
- CERN’s Large Hadron Collider
- Collision beams
- Oxygen and proton beams
- Measurement
- Particle numbers, energies, and angles
- Imaging equipment
- A 100-million-pixel camera
- Publication
- Physical Review Letters
- Main finding
- Earlier models of this interaction were significantly inaccurate