Two significantly large asteroids, or small moons/planetoids, became embedded in the underside of the city-sized JMC mining spaceship Red Dwarf at some point in the early years of it's mission. The two asteroids were already present before Red Dwarf left Earth's solar system, and were still embedded in the underside of the ship three million years later.
The background and purpose of these asteroids is unclear. In the early television series, the model of the ship made it appear as though the inclusion of the two asteroids was fairly jagged, implying that they had impacted into the underbelly of Red Dwarf.
Since it was a mining ship, it is possible and even likely that the inclusion of the asteroids into Red Dwarf was not a result of meteor impacts, but was deliberate and intentional on the part of the JMC. This would have given the crew a continual source of ore to mine from within the ship as they went on their rounds around the solar system. This appears more so in the remastered version of the ship, and also in the nanobot-upgraded ship of Series VIII, where it seems as though the ship had been constructed around the two asteroids.
- Early concept artwork for Red Dwarf (some of which can be seen in reconstructed episodes such as "Bodysnatcher" and "Dad") show that the two asteroids were originally to have been much bigger before the model was built, with the ship itself shaped by the contours of the asteroids. When the model was built it retained the asteroids, but toned them down in size and prominence somewhat.