why did the vikings go exploring in the first place?

[esta1989]

why did the vikings go on the journey that caused them to end up in north america?

[bernardo]

Imperialist colonisation and the search for resources to exploit.

[zmudge]

The Vikings were a jolly lot and simply loved the fun and mayhem that went with exploring. Late in the 8th century AD, strange ships began appearing along the coasts of Europe. They were strongly built of oak, and from 40 to 60 oarsmen sat on the rowers' benches. Each ship had a single mast with a square sail that was often striped in brilliant colors. Bright shields overlapped along the gunwale. The ships were pointed at each end and had tall curved prows, usually carved in the shapes of dragons. Dragon ships usually appeared in a bay at dawn. Armed with swords and battle-axes, the oarsmen loved to attack the  villagers and load and sail away with all the loot that their ships could carry. These happy marauders, or pirates, came from Scandinavia, now Denmark, Norway, and Sweden. whose people were Norsemen, or Northmen. Those Norsemen who took part in these swift, cheerful raids along the coast were called Vikings. Their name was given to the era that dated from about AD 740 to about 1050 -- the Viking Age. Norsemen loved games. They played ball games on the ground and on ice. Wrestling and fencing were popular sports. Norsemen used skates made of the bones of animals. According to a Norwegian historian, an unusual sport involved walking on oar blades while a boat was being rowed. When raiding European villages they extended their sense of humour to the fun and sport in arson, pillage, burning, looting, murder, kidnapping, raping women and killing children. 
 

[Romeo]

Simple - they were looking for more land to farm and settle, and to see if there was anything worth plundering. Unlike the later Europeans, they were not interested in setting up trading colonies and plantations, nor were they consciously seeking to build up a world empire.

[dothawkes]

Was it not just cos it was a bit warmer further south?

[Octavius]

They just got lost

[Octavius]

Here is a good article:

http://www.strangehorizons.com/2001/20010827/vikings.shtml