The location of the solar system's outer boundary is a point of contention among astronomers. There are three possible candidates, which "all have merit." But which one is best?

What is the most dangerous asteroid, how probable is an impact, and how much destructive power would a collision with Earth have? Here are 5 big space rocks that NASA is watching closely.

An illustration of the solar system (not to scale), including the sun, inner rocky planets, asteroid belt, the outer gassy planets, and—beyond Neptune—the Kuiper belt and the Oort cloud.

Our Solar System is full of mysteries, but if the inner planets are a puzzle, the boundary between the Solar System and interstellar space is a secondhand puzzle with half the pieces missing.

New evidence points to a carbonaceous asteroid from the outer solar system as the culprit for Earth’s most recent mass extinction. Skip to main content. Scientific American. August 14, 2024.

The answer depends on how you define coldest. Uranus boasts the lowest recorded planetary temperature in our solar system: about minus 370 degrees , according to University College London.

Most meteorites, however, originate from the solar system's main asteroid belt—a vast region between the orbits of Mars and Jupiter where more than a million asteroids circle the sun.

The curious minds at What If explore how the discovery of Kepler 22-b in our solar system would alter everything we know about space and life.

When the Solar System was forming from a molecular cloud around 4.5 billion years ago, temperatures in the inner region were too high for volatile chemicals such as water to condense.

A hidden structure at the farthest reaches of our solar system is challenging long-held theories. Using advanced simulations, a NASA supercomputer has revealed that the Oort Cloud, a vast shell of ...

NARRATOR: Our solar system is home to eight planets, near-perfect spheres spinning through the darkness of space. But the more we explore, the more weird and wonderful worlds we discover.