30 January, 1998. Comet Hale-Bopp contained over 30 molecules,
including methanol and formaldehyde. Isotope ratios confirmed that
the comet came from the outer Solar System before being hurled into
the Oort cloud. Observations of Hale-Bopp made with the Extreme
Ultraviolet Explorer satellite indicated that cometary X-rays
result from the solar wind energetically slamming into the comets'
comas.