Astronomy
Kepler's first law - The reason why planets don't move in circles
Kepler’s first law revealed the true shape of planetary orbits. It is still used in modern Astronomy, for example, to predict the position of objects along their orbits.
How many moons does Pluto have?
Pluto’s moon system is one of the strangest in the Solar System. It has five moons (Charon, Styx, Nix, Kerberos, and Hydra). In this article, I’ll show you what makes each one different, why the Pluto–Charon pair is so unusual, and what scientists learned when New Horizons flew past in 2015.
Why is Pluto not a planet?
Pluto used to be the ninth planet. Many people born in the late 1990s still remember it that way. So why did its status change? The answer isn’t "because it’s too small". It is linked to a specific scientific definition agreed in 2006 by the International Astronomical Union.