I found a Golden Chest on the Moon. Is it just for simple loot? Are there others on the moon? How many are there?
Golden Chests just contain loot, yes. It's also worth noting that they scale on the area, not your level. So it's best to find them asap. You also are given an item for finding all the golden chests on a single planet. I know that you get a Sparrow from Earth and an Emblem from the Moon.
There's a few on each of the planets in-game at the moment. There are 5 on the moon
1 - Found during the The World’s Grave mission inside the cave full of cocoons.
2 - Head to the mission marker located in the large yellow building. Proceed until you find the green gas pit. Look nearby for a rock formation and orange lights.
3 - Another in The World’s Grave. When defending your Ghost search a nearby room with a little pool of water
4 - Inside the Temple of Crota during the Chamber of Night mission.
5 - The Summoning Pits Strike mission. After the final boss fight walk to the edge of the room and drop down onto a small platform
I'm affiliated with Gamers Heroes and we have a guide on the topic should you need more direction: Destiny Gold Chests Moon