Atmosphere of Mercury Atmosphere of Mercury Mercury has a very tenuous and highly variable atmosphere (surface-bound exosphere) containing hydrogen, helium, oxygen, sodium, calcium, potassium and water vapor, with a combined pressure level of about 10 bar (1 nPa). The exospheric species originate either from the Solar wind or from the planetary crust. Solar light pushes the atmospheric gases away from the Sun, creating a comet-like tail behind the planet. The existence of a Mercurian atmosphere had been contentious before 1974, although by that time a consensus had formed that Mercury, like the Moon, lacked any substantial atmosphere. This conclusion was confirmed in 1974
Imiloa Astronomy Center of Hawaii gift shop, and Sky Garden café are open to the public Tuesday through Sunday. An evening "Maunakea Skies" star talk is held in the planetarium on the last Saturday of each month. In the Hawaiian language, ‘Imiloa means "exploring new knowledge." It is located at 600 ‘Imiloa Place in Hilo, just north of Hawaii Route 2000 (Pūʻāinakō Street). In September 2012 the Sagan Planet Walk, until then located only in Ithaca, New York, was extended with a statue representing Alpha Centauri installed at the Imiloa Astronomy Center. This made the Sagan Planet Walk the world's largest exhibition. Imiloa Astronomy Center