More than 1 million asteroids left over from the early formation of our solar system orbit the sun in the main asteroid belt between Mars and Jupiter. Tens of thousands more orbit outside that belt.
Hours of research by our editors, distilled into minutes of clarity.
The biggest of these (that we know of) is 16 Psyche. Measuring 140 miles across, its iron and nickel content is potentially worth 10,000 quadrillion dollars. NASA’s mission to Psyche—reaching the asteroid in 2029—will study it to learn about its formation.
Even those large enough to cause local or regional damage are too small, dim, and far away to be observed readily from cosmological distances. New tools, like NASA's NEO Surveyor telescope, aim to address gaps in detection systems.
Most of this matter comprises small particles, with any smaller than 33 feet in diameter burning up in the atmosphere. Larger asteroids can reach the ground, and those larger than several thousand feet cause global damage, including earthquakes and tsunamis.
Astronomers identified asteroid 2024 YR4 in early 2025, initially giving it a 3.1% chance of hitting Earth in 2032—the highest ever probability for a large asteroid. This sparked global planetary defense plans, but further observations soon ruled out any significant impact risk, bringing relief worldwide. Here's the story of how it unfolded.
A new study suggests that Venus' co-orbital asteroids—space rocks that lag ahead or behind the planet—could potentially destroy cities if they strike Earth. While no observed co-orbitals currently pose a threat, observational bias prevents observation of those of greater risk.
Isotopic evidence confirms the rock was a carbon-rich asteroid, likely born beyond Jupiter and later knocked into Earth’s path after billions of years of orbital drift and gravitational nudges. Its path spanned over four billion years and ended in the extinction of 75% of life, including all non-avian dinosaurs.
This three-minute video overview explains NASA's ambitious test to slightly alter the course of an asteroid by slamming a fast-moving space probe into its surface. Scientists hope to one day, if needed, use the technique to protect Earth from an asteroid impact.
The Kuiper Belt is a collection of extraterrestrial objects that might've been a planet if it hadn't been for Neptune. Still, the belt is a fascinating collection of dwarf planets, rocks, ice, and comets. Extending beyond Neptune's orbit, the Kuiper Belt provides an endless selection of interesting objects and anomalies for astronomers to explore.
This article explores how mammals and other critters that would eventually evolve into humans managed to survive and thrive after an asteroid smashed into Earth 66 million years ago, wiping out dinosaurs. The asteroid slammed into the Yucatán Peninsula of present-day Mexico with the force of more than 1 billion nuclear bombs, according to this article, setting off a chain of baneful events, including earthquakes, tsunamis, and darkened skies filled with soot. Only about 7 percent of mammals are estimated to have survived the initial blast and ensuing chaos, and they likely were aided by their generalist diets and ability to give birth to live young.
Asteroids are zinging by our planet regularly, and some of them you can see without a telescope. Here's a regularly updated list of the next five asteroid approaches.
Since our ancient human relatives began using stone tools to perform tasks, humans have harnessed scientific knowledge and new technologies to expand the boundaries of our understanding of the natural world. From quantum computing and microplastics to artificial intelligence and memory, explore these topics and more with our concise yet informative overviews and expert-curated resources.