From Destinypedia, the Destiny wiki
ARENA DESIGNATION: First Light
What was once an unassuming exobotany laboratory complex turned into ringside seats to the end of the world during the Collapse. Immense fissures in the Moon's crust spew a sickly yellow miasma, and hint at the utter destruction going on deep beneath the surface. Whatever the Hive are up to, they've been at it a long time, and they're not overly concerned with keeping Luna in one piece.
First Light is a sloped map, with steep hills and cliffs (one team starts at a higher elevation) and is medium-large in size, and includes light vehicle combat, use of Pikes, Interceptors, and Sparrows to quickly get from place to place, and large area control.
Occupying the high ground does not necessarily confer an advantage, as numerous access points allow players to flank or rear attack. Occupying the large structure in the middle of the map allows players to access most other areas of the map and return to safety swiftly.
Three stationary turrets placed around the map provide heavy firepower for quickly destroying vehicles or groups of enemy players, but are not accurate from a distance and contain little in the way of defense. A well-placed sniper rifle shot or a sneak attack from behind can quickly end a turret streak.
The Interceptor is slow-moving but easily outguns other vehicles and players on the map. Counter the Interceptor by attacking it from a turret, with heavy weapons, or shooting the driver when the vehicle is facing away from you. The Pike provides less firepower but more speed, and can be countered in a similar manner.