NASA sent the Lunar Reconnaissance Orbiter (LRO) to the Moon to spy out sites for future manned missions. It doesn't look like they'll be sending anybody to the Moon, but LRO has documented the Apollo landing sites. Astronomy writer and space expert Ian Ridpath takes us to the Moon for a look.

The Prime Meridian of the World is “where time begins” at zero degrees of longitude. By international agreement in 1884, it was located at Greenwich, England. But if you stand on that meridian and look at the GPS on your phone, it won't read zero. What happened?

Achievements may be honored with prizes and medals, but few get represented as children's toys. However Lego responded to a proposal to showcase women in space and astronomy by making a Lego set representing four such women and their major contributions. Who were these women?

We walked on the Moon. Rovers explore Mars. The International Space Station has been continuously inhabited since 2000. We're in contact with the world and the cosmos via satellite. We take it for granted, but there had to be a first time for everything. How many of these space firsts do you know?

In the ABC of astronomy, astronomy itself is the first and most important item. What is astronomy and how does it differ from astrology? What are the main specialist areas in astronomy and how do they contribute to the overall picture?

Pluto's not the last planet, it's the first Kuiper Belt Object. The Kuiper Belt is made up of millions of icy bits left over from the beginning of the Solar System. It starts at 30 AU - that's 30 times farther from the Sun than the Earth. From there it stretches for another 2 billion miles!

White dwarfs are the corpses of medium-sized stars that have run out of fuel. They typically have the mass of the Sun, while being about the size of the Earth. It's no wonder that early twentieth century astronomers were dumbfounded by them.

There are three constellations named for dogs, but what about cats in the sky? There is astrocat Felicette who went into space and returned safely to Earth, but also constellations of big cats and a pawprint 50 light years across.

No one could possibly say that a star is the smallest one in the whole Universe. But the smallest known star is 2MASS J05233822-1403022, which is a pretty big name for a star that's about the size of Saturn. Could there be even smaller ones as yet unknown?

Betelgeuse is the star that represents the right shoulder of Orion the hunter. It's also one apex of the Winter Triangle, and it marks the center of the Winter Hexagon. Being bright red-orange and part of the hunter's commanding presence, it's not hard to find in the winter sky.