COBALT DISELENIDE
Cobalt Diselenide is a biogenic weapon that attacks the nervous system. It is harmless to humans and most other humanoids, but lethal to Cardassians.

The agent can be synthesized from selenium and rhodium nitrite, and must be kept at a low temperature in order for it to remain stable.

This weapon was first mentioned in Star Trek, Deep Space Nine, Season 5 Episode 13.

BACKGROUND IMAGE
This picture of Saturn's moon Hyperion reveals crisp details across the moon's surface. The view was obtained during Cassini's very close flyby on Sept. 26, 2005.

Hyperion has a very low density, about half that of water. This is possibly due to a vast network of internal caverns making the moon partially hollow, and the composition which is believed to be a mix of water and carbon dioxide ice containing dust.

Hyperion might have had a major collision which blew part of the moon away. Its eccentric orbit makes it subject to gravitational forces from Saturn which have set it tumbling out of control. The moon's rotational period is not constant and varies from one orbit to the next.

Hyperion is actually the largest-known irregular-shaped body.

Radius: 205x130x110 km
Distance from Saturn: 1,481,100 km