Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

This artist’s concept depicts one of the solar system’s inner planets slamming into Earth after being nudged on a collision course by a passing star. Such a world-shattering cataclysm is extremely ...

Mercury has long baffled astronomers because it defies much of what we know about planet formation. A new space mission ...

The newly identified cluster of Kuiper Belt objects lies about 4 billion miles from the Sun, offering fresh clues about how ...

There are a couple of ways that scientists can date planets, so which planets formed first in our solar system? When you purchase through links on our site, we may earn an affiliate commission. Here’s ...

For the first time since Pluto was demoted, the idea of a true ninth planet is edging from speculation toward something ...

The Sun's formation caused temperature differences in the surrounding disk of gas and dust. Inner, hotter regions formed rocky planets from less volatile elements. Outer, colder regions allowed ...

How many dwarf planets are there in our solar system? The recent discovery of 2017 OF201 makes the tally anywhere between five and 18, plus hundreds of potentially undiscovered ones, depending on whom ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

A tiny meteorite is rewriting what scientists thought they knew about the origins of our solar system. New evidence found in shavings from a meteorite known as Northwest Africa 12264 — a 50-gram (1.8 ...

Snapchat Planets, part of the Snapchat Plus Friend Solar System, ranks you in a friend’s top 8 based on your interactions, from Mercury (#1) to Neptune (#8). Each friend has their own solar system ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...