Larger Molecules in Space
For many people one of the most interesting question ever asked is "is there life out there?". This simple question is one mankind has tried to answer for centuries and although many believe that there is extraterrestrial life we still lack the proof. The interstellar medium does suggest that it is possible for life to exist elsewhere in the universe.
Molecules have been found in the interstellar medium by sweeping the radio frequencies of the electromagnetic spectrum. Many simple molecules such as CO, CN and OH have been detected, but to many people it is the discovery of complex organic molecules, such as formaldehyde (H2CO) and methanol (CH3OH), which are of the most interest. Amino acids are the basic building blocks of life and all the reagents which are used in a laboratory to synthesize such molecules are available in the interstellar medium.
Most of these molecules are formed via a sequence of two-body, ion-molecule processes in the gas phase, using interstellar grains as a catalyst. The majority of molecules found in the interstellar medium are found in giant molecular clouds, where the density tends to be higher and the probability of a collision is appreciably higher. Another reason that molecule formation is favoured in large clouds is that in the core of these clouds is protected from ultraviolet radiation by the atoms, ion around the edges.
Diatomic
HD
deuterized hydrogen
CN
cyanogen radical
OH
hydroxyl radical
CO
carbon monoxide
SiO
silicon monoxide
CS
carbon monosulfide
SO
sulfur monoxide
C2
carbon
NO
nitric oxide
Triatomic
H2O
water
CCH
ethynyl radical
HDO
heavy water
HCN
hydrogen cyanide
H2S
hydrogen sulfide
HCO
formyl radical
SO2
sulfur dioxide
DCN
deuterium cyanide
4
Atomic
NH3
ammonia
H2CO
formaldehyde
HNCO
hydrocyanic acid
H2CS
thioformaldehyde
HC2H
acetylene
5
Atomic
CH4
methane
H2HCN
cyanamide
HCOOH
formic acid
HC3N
cyanoacetylene
6
- Atomic
CH3OH
methyl alcohol
HCONH2
formamide
8
Atomic
HCOOCH3
methyl formate
9
Atomic
CH3CH2OH
ethyl alcohol
11
Atomic
HC9N
cyanotetraacetylene