The atmosphere is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface; data from the Mars Exploration Rovers indicate that suspended dust particles of roughly 1.5 micrometres diameter.
Glutamate is a powerful excitatory neurotransmitter that is released by nerve cells in the brain. It is responsible for sending signals between nerve cells, and under normal conditions it plays an important role in learning and memory.
Glutamate. Glutamate is an excitatory relative of GABA. It is the most common neurotransmitter in the central nervous system-as much as half of all neurons in the brain-and is especially important in regards to memory. Curiously, glutamate is actually toxic to neurons, and an excess will kill them.