Shooting stars are streaks of light produced by meteoroids

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

Shooting stars, or meteors, are fragments of asteroids and comets that burn up as they enter Earth's atmosphere, creating streaks in the sky called meteor showers.

A 101 on the science and history of meteor showers

Bits of rock, ice, and dust flying through space called meteors burn up in a spectacular display when they hit our atmosphere 60 miles up at an average of 30,000 mph. Some of these are isolated objects, but others are recurring phenomena caused by...

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

The importance of the mesosphere, the coldest part of Earth's atmosphere

Atmospheric gases are dense enough in this region to begin burning up debris traveling toward Earth's surface, producing meteor showers, or shooting stars. Although we normally associate decreasing temperatures with increasing altitude, temperatures increase beyond the mesosphere layer due to the absorption of high-energy ultraviolet radiation and X-rays.

Colorful thunderstorm phenomena can be viewed from the International Space Station

Transient luminous events are lightning-related phenomena that occur in the atmosphere above storm clouds. These events often look like columns of red light resulting from electrical discharge, but may also appear as purple tendrils or long blue jets.

Stellar photos from around the world of the 2020 Perseids

The annual Perseids meteor shower occurs in the Northern Hemisphere's summer, peaking usually around mid-August. The phenomenon is caused by the Earth's passing through a comet's debris trail of ice and dust, providing a weekslong spectacle for...

Aurora-like magenta streaks across the sky may not be auroras

The phenomenon, known as STEVE (Strong Thermal Emission Velocity Enhancement), has only been observed alongside auroras. Rather than light emitted by gases energized by collisions with ionized particles from the sun, STEVE is a high-velocity, high-temperature stream of particles that glows. (Some readers may experience a paywall.)

Scientists have tested atmospheric models by firing rockets into the aurora borealis

Functioning like components of a CT scan, the missiles transmit signals that can be used to identify charged particles and electromagnetic currents in slices. The slices are then combined to construct a computer-based model of Earth's atmospheric structure, which is used to compare the accuracy of physics-based models.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

Watch over a dozen fireworks effects

Adding pellets of salt to gunpowder within a fireworks shell causes them to explode with different colors, but the type of gunpowder used also has an effect. Finely ground gunpowder burns quickly, producing streaks that swiftly burn out.

Explore a guide to observing comets

Binoculars or telescopes can be used to see vivid tails, glowing comas, and brief bursts of brightness from these celestial objects. For photography, a DSLR or mirrorless camera with a wide-aperture lens, long exposure settings, and accessories such as tripods and star trackers is recommended.

What the stars once meant to ordinary people

The stars were a crucial aid for ordinary human beings in premodern societies, acting as regular timekeeping phenomena and celestial navigators. Today, light pollution and modern technology have rendered the stars a mere aesthetic delight for most of us, but their significance in history remains. Watch this brief video to learn how premodern humans used the stars for navigation, mathematics, and more.

Metal fragments can create glowing rings when sand chips them off helicopter blades

The Kopp-Etchells effect—named after two soldiers who died in action in Afghanistan—may occur when kicked-up material shaves off fragments from a helicopter blade's abrasion strip. Due to a property called pyrophoricity, the fragments react with air and ignite, producing halos.

You are 65,000 times more likely to be struck by lightning than to be hit by space trash

In 2023, about 1,500 pieces of space junk fell to Earth, with most consisting of payload fragmentation debris. The vast majority that falls back to Earth burns up before reaching the surface, making it three times less likely to be struck by space trash than by a meteorite.

Astronomers use a star's color to determine how fast it's moving

According to the Doppler Effect, light from objects moving away from Earth shifts toward the red end of the electromagnetic spectrum, with the severity of the shift correlating to recession speed. Due to the universe's expansion, light from the most distant galaxies can be moved from ultraviolet to infrared.

Fireworks make a loud booming sound after exploding due to air expanding faster than the speed of sound.

Ballistic experiments show that tardigrades are unlikely to be an alien species

Those fired from guns at speeds as high as 825 meters per second (1,845 mph) could be resuscitated after impact. Shock pressure from greater speeds tore apart the samples, suggesting they could not survive asteroid impacts if brought to Earth from outer space.

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

The different energy levels of each element result in unique colors when burned

When heated, electrons absorb energy and move to excited states within an atom. They promptly drop back down and release light energy corresponding to the size of the drop, which is unique to each element.

Cloud chambers use alcohol vapor to create trails behind passing cosmic rays

As cosmic rays travel through the air, they collide with molecules to form charged fragments called ions. Vapors in the chamber condense around these ions, creating streaks of tiny droplets that mark the paths where cosmic rays or their secondary particles traveled.

What are pulsars?

Pulsars are neutron stars created as part of stellar evolution and emit radiation beams visible from Earth. These beams pulse like a lighthouse's light due to the star's rotation, creating periodic high-energy emissions. Pulsars were first discovered as radio sources; it was also discovered they emit gamma rays. NASA uses its Fermi Gamma-ray Space Telescope to retrieve and analyze data from pulsars.

Dark stars are hypothetical stars that would have existed in the early universe

Primarily composed of visible matter, this celestial object would also contain a significant amount of dark matter that would annihilate with itself, converting its mass into energy. This energy would prevent the star from collapsing under its own gravity and from triggering nuclear fusion until its dark matter fuel was exhausted.

Tiny water droplets can blur a rainbow's colors into a foggy white

When sunlight enters water droplets, it can reflect from the inside and spread out into different colors, producing a series of colorful arcs—supernumerary bows—which we refer to as rainbows. For droplets a few hundredths of a millimeter in size, these arcs overlap onto each other, producing fogbows of white light.

The lifetime of a star is determined by its initial mass

More massive stars burn through their fuel at ever-increasing rates, causing them to have shorter lifetimes than less massive stars, despite starting with more hydrogen to fuse. In clusters of stars that likely formed together, observing what mass stars are no longer fusing hydrogen estimates the age of the cluster.

Fireflies light up to provide mating signals and warnings to predators

Variations in the illumination patterns and flight paths while emitting light have been observed across firefly species. Some species instead rely on pheromones if they are primarily active during the day or have lost the ability to illuminate.

Space tourism rockets emit up to 100 times more CO₂ per passenger than airplanes

Rocket launches release significant amounts of water vapor, nitrous oxide, and rocket propellants, which generate greenhouse gases and air pollutants. High-altitude emissions can persist for years, affecting the ozone layer.

Astronauts agree: The moon smells like gunpowder

Twelve astronauts have walked on the moon to date, and they all agree that our lunar neighbor smells like gunpowder. Scientists argue this scent comes from unstable minerals that cling to their suits and the rocks they return to the ship. Notwithstanding, space itself has a different smell, often compared to steak or metal, which experts believe, rather poetically, is the smell of dead stars.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

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

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

The deadliest aspect of volcanic eruptions is often not lava, but pyroclastic flows—avalanches of ash, gas, and rock that can move more than half the speed of sound.

See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

When caught in the mouths of cardinal fish, seed shrimp release glowing, bioluminescent chemicals, which alert predators of the cardinal fish, prompting the shrimp's ejection.

Apollo astronauts left items in the moon's 'toss zone,' including golf balls, family photos, and bags of human waste, to make room for lunar rocks.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

Georgia O'Keeffe's flower paintings are often assumed to be sexual, though the artist claimed she was simply interested in highlighting the beauty of flowers that most people neglect

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

See photos of Meteora, a mountainous site in central Greece, home to 14th-century monasteries perched atop soaring outcroppings.