The International Astronomical Union (IAU) defined a dwarf planet in 2006 as a celestial body that orbits the Sun, is round in shape, but has not cleared its orbital neighborhood of objects of ...

Explore planets, stars and more!

Free to print My Little Book of Planets—a fun, free printable space mini book for kids to color, trace, and learn about planets, space vocabulary, and more! Looking for a simple and fun way to teach ...

The ancient Greeks proved over 2,000 years ago that the Earth was round and figured out how big it was by using simple observations of the Sun. But how do people know this today? When you drop ...

Have you ever looked up on a clear night at the stars and noticed that some of them seemed to twinkle or dance? This twinkling is due to the Earth’s atmosphere. When light reaches Earth from a star, ...

Dr Rudi Kuhn does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...

Earth is quite special among its rocky terrestrial friends: Mercury, Venus and Mars. It is the biggest and heaviest of this group. If you think about it, Earth is quite big – about 12,700 kilometres ...

Why is Christian Science in our name? Our name is about honesty. The Monitor is owned by The Christian Science Church, and we’ve always been transparent about that. The Church publishes the Monitor ...