But the agency continues to study other short-lived radiological particles.
Launched on 8 November 1969 it studied the Van Allen belts, solar particles, and aurorae.
Complex mathematics are used to study subatomic particles and electromagnetic waves because they act in very strange ways.
Synchrotrons were originally designed for use by high-energy physicists studying subatomic particles and cosmic phenomena.
Physicists are able to study subatomic particles at energies far greater than those seen in ground-based particle accelerators.
In modern instruments, the beam is generally polarized, though other polarizations may be used especially when studying anisotropic particles.
Virologists also study subviral particles, infectious entities notably smaller and simpler than viruses:
Today, the number probably exceeds 1,000, astronomers being increasingly joined by scientists who study elementary particles and theoretical astrophysicists who rarely get near a telescope.
The National Science Foundation is considering building a deep underground laboratory, primarily to study wispy subatomic particles known as neutrinos.
The cloud chamber also needs time to reset between recording events and cannot keep up with the high-energy accelerators used in studying strange particles.