Astronomers using theJapanese Subaru Telescope on Hawaii have detected frozen ethane on the surfaceof Pluto. Ethane, a substance prized on Earth as a component of natural gas,may have even greater significance on Pluto, where it could provide clues tothe evolution of the early solar system.
Indeed, the ethane ice maybe a remnant of the vast gas cloud that collapsed some 4.5 billion years ago tobecome the sun and planets. The substance may have been preserved since then bythe extreme cold that exists at the distance of Pluto's orbit.
Alternatively, the ethanemay have been created throughout the lifetime of the solar system from thereaction of methane and ultraviolet light. Further observations may determinewhich of these two theories is correct.
The ethane is dissolved ina bed of nitrogen ice that covers much of Pluto's surface at a temperature of-387 degrees F (-233 degrees C).
The Subaru Telescopeconducted the observations in June. The telescope, owned by the National AstronomicalObservatory of Japan, saw "first light" earlier this year but isstill under construction. It is scheduled for routine operation in 2000. Thetelescope's Cooled Infrared Spectrograph/Camera observed both Pluto and itsmoon Charon.