Trillions of neutrinos travel through your body every second without leaving a trace.

After photons—particles of light—neutrinos are the most abundant particles in the universe.

Learn about solar neutrinos—about 70 billion of which pass through your thumbnail every second

A beam of neutrinos can be created by firing a beam of high-energy protons at a target to produce unstable particles that decay into neutrinos.

The IceCube Neutrino Observatory has detected high-energy cosmic neutrinos since 2013 using an array of 5,160 sensors enclosed in Antarctic ice.

IceCube is a neutrino detector housed in a cubic kilometer of ice beneath the Antarctic surface.

Scientists can map Earth's shape and structure by measuring the ratios of certain particles arriving from different directions in space, as these ratios change with the density of the material particles travel through.

Some cosmic rays possess energies as high as 100,000,000 teraelectron volts—more than 10 million times the energy of particles accelerated in the Large Hadron Collider.

Antimatter was discovered by examining debris from collisions between atmospheric gases and cosmic rays—high-energy matter particles from space.

Earth's magnetic field, which deflects charged particles, helps protect us from cosmic rays, but the sensitivity of these particles to magnetic fields also makes it difficult for astronomers to determine their sources.

Scientists have determined the properties of cosmic rays by analyzing their trajectories in bubble chambers—containers filled with a vapor that clings to charged particles.

Explaining why solving the solar neutrino problem revealed that neutrinos could transform

Particles produced in cosmic-ray showers that would normally decay long before reaching Earth's surface are observed by ground-based detectors, as predicted by special relativity.

Fermilab's ICARUS experiment is searching for hypothetical sterile neutrinos

If particle accelerators did create black holes by packing tremendous energy into a small volume, then trillions would be created in Earth's atmosphere daily by cosmic rays.

Cosmic rays are thought to be accelerated to near the speed of light by repeatedly bouncing across shockwaves produced by high-energy cosmic events, such as supernovae.

In 1997, the Compton Gamma Ray Observatory identified 'positron geysers'—fountains of antimatter particles—emerging from near the center of the Milky Way.

Cosmic rays are evidence of incredibly powerful astronomical events—solar cosmic rays provide information about eruptions and flares on the sun's surface, while galactic cosmic rays shed light on dying stars.

Neutron stars, the remains of some massive stars after they explode in a supernova, are the densest directly observable objects in the universe.

Particle accelerators detect subatomic particles using millions of sensors

In 2017, a hidden chamber was found in the Great Pyramid of Giza by measuring particles created in the collisions between cosmic rays and atmospheric particles.

If the entire universe were replaced with antimatter, except for Earth, our planet would slowly be annihilated from the outside in as it moved through space.

View a ranking of the masses of fundamental particles, from the massless photon to the top quark, and a timeline of their discoveries.

At CERN's Antimatter Factory, researchers create and guide antiprotons and antielectrons together to form antihydrogen, and all these antiparticles are analyzed to help scientists study the behavior of antimatter.

Antimatter can be created from dark lightning—high-energy light emitted by deflected electrons after they are accelerated to near the speed of light by thunderstorms.

Leptons do not experience the strong nuclear force that binds quarks together

Why starquakes may explain various phenomena associated with neutron stars

Learn how to build your own cloud chamber to detect cosmic rays—particles from space that move near the speed of light—at home.

Research shows that cosmic rays may trigger the cascade of displaced electrons needed to produce lightning, which is also enabled by pointed ice crystals that create strong electric fields.

Antimatter's rarity across the cosmos is one of the biggest problems in modern physics because the high-energy environment of the early universe should have produced equal amounts of matter and antimatter.

Antimatter stars would appear identical to normal stars and be similarly powered by nuclear fusion, but they would be extremely short-lived in a matter-dominated universe.

Less common types of radioactive decay include emitting neutrons and antimatter

Fritz Zwicky predicted the existence of dark matter and neutron stars

Delays in the decay of unstable particles provide evidence for time dilation

Dark energy was discovered using Type Ia supernovae—exploding white dwarfs whose peak brightness can be calibrated to measure distances across the universe.

Each year, the Large Hadron Collider undergoes a winter shutdown—when electricity costs are highest—and bringing it back online requires weeks of tests, including some involving high-energy particles from outer space.

Despite fears of creating black holes, the Large Hadron Collider produces collisions with energies of 13.6 trillion electronvolts, about one million times smaller than the energy needed to create the lightest possible black holes.

As seen in the dark region of the Horsehead Nebula, clouds of space dust can block some forms of light from reaching telescopes, impairing observations and data collection.

Some theorists have suggested that dark matter consists of supersymmetric particles—massive, hypothetical versions of known particles, such as the sneutrino, which is the supersymmetric partner of the neutrino.

Plasma makes up 99% of the observable matter in the universe, despite being considered the fourth state of matter.

The hypothetical matter that neutron stars' cores may contain, including strange quarks

Cosmogenic nuclide dating reveals how long a surface has been exposed to air by measuring the abundance of rare isotopes produced when cosmic rays interact with minerals.

The Higgs boson is a quanta, or discrete piece, of the Higgs field, which gives elementary particles, such as quarks and electrons, mass as they travel through it.

View summaries of the most common types of radioactive decay and their associated particles

Learn about five of the largest particle accelerators on Earth, which, as of 2026, are led by the Large Hadron Collider at the European Organization for Nuclear Research.

Antimatter particles possess the same mass and spin as their normal particle counterparts, but possess an opposite charge and transform into pure energy upon colliding with normal matter.

A look inside neutron stars, which are thought to contain nuclear pasta

Explaining pulsars, the cosmic clocks and lighthouses of the universe

By measuring them in hot-air balloons during a partial solar eclipse and at night, Victor Hess discovered cosmic rays and concluded they came from beyond the solar system.

Cosmic rays can be detected using cloud chambers—containers where alcohol vapor condenses around trails of ions created by these high-speed particles from space.

It may be possible to create dark matter in particle accelerators