| Both comets and asteroids are the left-over building blocks of the planets in our solar system. |
| It has been suggested that impacts with comets and asteroids provided Earth with much of its water. |
| They will be studying water, carbon monoxide, ammonia and methanol four of the most abundant gases from comets. |
| In contrast, Jupiter-family comets tend to have predictable, well-determined orbits with short periods and low inclinations. |
| According to Brownlee, the loose aggregate of particles seen on comets may represent the first generation of solids in the solar system. |
| In many ways asteroids and comets are likely to offer more varied and abundant natural resources than the Moon. |
