Solar System
How big is the Solar System?
The scale of our Solar System is gigantic. There’s more to our cosmic neighbourhood than eight planets and an asteroid belt.
How long is a year on each planet?
Black on white or white on black? The mystery of Saturn's weird two-toned moon
Patrick Moore reveals interesting facts about Saturn's strange black and white satellite in this archive article.
Strangest things in our Solar System
How many stars are there in our Solar System?
A simple answer to a simple question is key to our understanding of the Universe.
Astronomy explained | The Planets
A guide to the planets of the Solar System, their order in distance from the Sun, and facts about the rocky terrestrial worlds and the gas giants.
The planets return! Solar System worlds will be spectacular in the latter half of 2024. Here's how to see them
The worlds of our Solar System make a spectacular return to the night sky in the second half of this year.
A guide to rings around planets and across the Solar System
Our Solar System is full of rings, and not just around the planets.
Star Diary | 15 to 21 July 2024
Strike! 10 biggest impact craters in the Solar System that show how chaotic our cosmic backyard really is
What are the biggest impact craters on Earth and across the Solar System?
How we learned to put the Sun at the centre of the Solar System. Geocentrism vs heliocentrism explained
Earth orbits the Sun, right? It turns out this simple fact wasn't always so simple.
How astronomers weighed the Kuiper Belt
Using data from the Cassini mission, astronomers have come up with an ingenious method of calculating the mass of trans-Neptunian objects.
How many planets are there? It's a trickier question to answer than you might think...
What makes a planet? How many are there in our Solar System and the wider Universe?
Voyager 1 is back in working order after five months of silence
Which planet and Solar System bodies have largest oceans?
Saturn's moon Mimas has an ocean
A newly discovered ocean on Saturn’s moon Mimas could provide a unique place to study the habitability of our Solar System.
Where's the edge of the Solar System, and what do we find in the outer realms of our cosmic neighbourhood?
Where is the edge of the Solar System, and what's going on out there?
How long is a day on Mars? This is how NASA scientists measure the length of a day on the Red Planet
Mars days vs Earth days, sidereal vs solar: how long would you have if you spent a day on the Red Planet?
How old is the Solar System? Astronomers calculate its age by studying rocks that fall from space
How do astronomers know the age of the Sun and planets?
What is the biggest planet in our Solar System and in the known Universe?
Find out which is the biggest planet in our Solar System and some of the biggest exoplanets.
Why Neptune is blue? A recent discovery suggests we've been given a false view of the planet for decades
What makes planet Neptune blue and why did a recent discovery claim its colour is actually more like Uranus's than conventionally thought?
Why is Venus the hottest planet, if Mercury is the closest to the Sun?
Mercury orbits closer to the Sun, so why isn't it hotter than Venus?
Saturn's moon Titan may have 'magic' disappearing islands floating on its liquid methane seas
Transient isles form then dissolve on Saturn moon’s seas
Moons of Uranus
Discover facts about Uranus's moons, when they were discovered, who they're named after, which are the biggest and smallest.