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.
The carboxylate anions and salts of glutamic acid are known as glutamates. Glutamate is the most abundant excitatory neurotransmitter in the nervous system and it plays a key role in long-term potentiation. It is involved in most aspects of normal brain functions, including cognition, memory and learning.