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Small BodiesStories, updates, insights, and original analysis from The Planetary Society.
Messengers of ice and time
Comets are ancient relics from the Solar System's formation that may have delivered water and the building blocks of life to early Earth.
How do you define a planet?
As our ability to study space has improved, our definitions of planets have evolved.
Beyond the unknown: The coming Kuiper belt revolution
Discoveries about the worlds of the Kuiper belt could revolutionize our understanding of the Solar System and its ancient past.
Why do some planets have rings and others don't?
The giant planets of our Solar System all have rings, as do some dwarf planets and even asteroids. So why don’t Mercury, Venus, Earth, or Mars?
What is comet 3I/ATLAS?
A roundup of key facts and surprising discoveries about the third known interstellar object.
Where do 3I/ATLAS and other interstellar visitors come from?
Interstellar interlopers like 'Oumuamua and 3I/ATLAS could be our best bet at exploring other stars.
Studying a distant visitor: What we know about Interstellar Object 3I/ATLAS
Key highlights from an interview with Dr. Bryce Bolin, lead author of a study on Interstellar Object 3I/ATLAS.
When space rocks get too close for comfort
Some of the best-documented encounters Earthlings have had with asteroids and meteorites.
Ten years after Pluto, New Horizons faces a new threat
The newly proposed budget for NASA would shut down the spacecraft midflight.
How astronomers rank dangerous asteroids (and what that means for you)
A breakdown of the Torino scale, designed to give a quick sense of how worried you should be about an asteroid or comet.
How to spot comet SWAN (C/2025 F2)
Catch this spectacular comet over the next few weeks.
Should you be worried about Asteroid 2024 YR4?
Experts weigh in about the recently discovered near-Earth asteroid 2024 YR4 that has about a 1% chance of impacting Earth on Dec. 22, 2032.
Hera launches to study the aftermath of an asteroid deflection test
The European Space Agency’s Hera spacecraft launched on Oct. 7, 2024, from Cape Canaveral, Florida. It will travel to the Didymos-Dimorphos asteroid system to study the aftermath of the first-ever field test of an asteroid deflection technique.
The Hera launch: What to expect
The European Space Agency (ESA) is preparing to launch a mission to study the aftermath of DART's impact on the asteroid moonlet Dimorphos.
Ramses: A new mission racing to land on asteroid Apophis
When a skyscraper-sized asteroid narrowly misses Earth in 2029, three spacecraft may be along for the ride.
Does Jupiter protect Earth from asteroids and comets?
Jupiter has often been thought to protect the inner Solar System from asteroids and comets, but new research has shown that the giant planet may actually increase the risk of an impact.
What are binary asteroids?
Binary asteroid systems can be found near Earth, in the main asteroid belt, beyond Neptune, and more.
What are asteroids made of?
C-type, S-type, and M-type are the three most common kinds of asteroids. Here's what each type is made of.
What DART has taught us so far
NASA's DART mission showed that if we detect a dangerous asteroid headed toward Earth, knocking it off course with a spacecraft is a potential option.
The hottest and coldest places in the Solar System
The worlds of our Solar System run the gamut of temperatures. Here are some of the hottest and coldest places we know of.