A New Spectral Feature on the Trailing Hemisphere of Europa at 3.78 microns

Understand

We present hemispherically resolved spectra of the surface of Europa from ~3.1--4.13 microns, which we obtained using the near infrared spectrometer NIRSPEC on the Keck II telescope.

• These include the first high-quality L-band spectra of the surface to extend beyond 4 microns.
• In our data we identify a previously unseen spectral feature at 3.78 microns on the trailing hemisphere.
• The longitudinal distribution of the feature is consistent with that of a radiolytic product created by electron or Iogenic ion bombardment.