THE SEARCH FOR POTENTIALLY HABITABLE EXOPLANETS HAS REVOLVED AROUND THE CENTRAL THEME OF AVAILABILITY OF SURFICIAL LIQUID WATER ON THE ROCKY BODIES1 2. HOWEVER IN ADDITION TO SURFICIAL LIQUID WATER THE PRESENCE OF LIFE-ESSENTIAL ELEMENTS SUCH AS N C AND S IN PLANETARY ATMOSPHERES PLAYS AN IMPORTANT ROLE IN THEIR DEEMED ABILITY TO HOST LIFE3 4. N MOLECULES AND COMPOUNDS LIKE N2