  The MicroBooNE neutrino experiment at Fermilab is constructing a liquid-argon
time-projection chamber for the Booster Neutrino Beam to study neutrino
oscillations and interactions with nucleons and nuclei, starting in 2014. We
describe the experiment and focus on its unique abilities to measure cross
sections at low values of $Q^2$. In particular, the neutral-current elastic
scattering cross section is especially interesting, as it is sensitive to the
contribution of the strange sea quark spin to the angular-momentum of the
nucleon, $\Delta s$. Implications for dark-matter searches are discussed.
