  Juno spacecraft's spectrometer JIRAM recently observed the moon Europa in the
2-5 {\mu}m wavelength region. Here we present analysis of the average spectrum
of a set of observations near 20{\deg}N and 40{\deg}W, focusing on the two
forms of water-ice - amorphous and crystalline. We also take this as an
opportunity to present a novel Bayesian spectral inversion framework for
reflectance spectroscopy. We first validate this framework using simulated
spectra of amorphous and crystalline ice mixtures and a laboratory spectrum of
crystalline ice. We next analyze the JIRAM data and, through Bayesian model
comparisons, find that a two-component intimately mixed model (TC-IM model) of
amorphous and crystalline ice is strongly preferred (at 26{\sigma} confidence)
over a two-component model of the same species but where their spectra are
areally/linearly mixed. We also find that the TC-IM model is strongly preferred
(at > 30{\sigma} confidence) over single-component models with only amorphous
or crystalline ice, indicating the presence of both these phases of water ice
in the data. For the highest SNR estimates of the JIRAM data, the TC-IM model
solution corresponds to a mixture with a very large number density fraction
(99.952 +/- 0.001 \%) of small (23.12 +/- 1.01 microns) amorphous ice grains,
and a very small fraction (0.048 +/- 0.001 \%) of large (565.34 +/- 1.01
microns) crystalline ice grains. The overabundance of small amorphous ice
grains we find is consistent with previous studies. The maximum-likelihood
spectrum of the TC-IM model, however, is in tension with the data in the
regions around 2.5 and 3.6 {\mu}m, and indicates the presence of non-ice
components not currently included in our model, primarily due to the limited
availability of cryogenic optical constants.
