Instructions
Fly towards the ice planet, which is located at the coordinates 73, 83. You'll receive a warning saying that there are space sharks ahead. Three sharks will be circling the ice planet, preventing you from landing.
Shoot any one of the sharks to get its attention. It's also possible to get their attention by flying close to them. Fly towards the coordinates 84, 47. Fly slowly enough for the shark to remain on the same screen as you. If you fly too quickly and lose the shark, then the shark will go back to guarding the planet instead of chasing you.
Fly close to the black hole at 84, 47 and the shark will get sucked into the vortex. Go back to the ice planet at 73, 83 and repeat this process for the two remaining space sharks. It is also possible to lure all three sharks away at the same time, but that greatly increases the chances of one of the sharks destroying your ship. Once you have lured all the sharks into the black hole, you will be able to land on the ice planet.