Comet

A comet is a small System Body that orbits the sun and, when close enough to the sun, exhibits a visible coma (atmosphere) or a tail—both primarily from the effects of solar radiation upon the comet's nucleus. Comet nuclei are themselves loose collections of ice, dust and small rocky particles, measuring a few kilometres or tens of kilometres across.

A Comet is an icy asteroid-like body orbiting stars in a highly eccentric orbit. In Aurora, Comets move towards the central star in a straight line and then turn 180 degrees, until they reach aphelion, then turn around 180 degrees again. Comets are a great source of material if you can harvest them. A few things to note:

1. Comets, like asteroids, have too little gravity and require expensive underground Infrastructure-based colonies or orbital habitats if you want inhabited settlements.
2. Comets always have moderate amounts of multiple minerals with high accessibility.
3. Comets can be mined with both Asteroid Mining Modules and Automated Mines.
4. Comets move slowly, but surely, on very large, irregular orbits.
5. Comets do not leave their system, but they will go billions of kilometers away from the central star before returning.

Minimum Comets per System is a New Game parameter. If you really like comets, you can set a minimum number per system. Comets are good in the sense that they usually have accessible mineral deposits, often in the ten of thousands of tons range, but bad in the sense they may disappear into the Oort cloud with your mining colony and come back in a few thousand years. Short period comets are much better for mining or you can make hay while the sun shines if a long period comet happens to be in the inner system for a while.

Obviously they provide a unique challenge, but can be quite valuable. Comets often have as much material as a small mineral rich planet, with the accessibility of an asteroid. A good way to tap them is to drop as many automated mines as you can and a mass driver on them while they're close, then use the mass driver to deliver the minerals to the most convenient stable solar body, be it a permanent colony or a way-asteroid to be freighted through a jump point. Since the packets neither slow down nor collide, even if the comet moves to the other side of the system the minerals will still reach your colonies eventually.