U and Th content in the Central Apennines continental crust: a contribution to the determination of the geo-neutrinos flux at LNGS

Ultra-Low Delta-v Objects and the Human Exploration of Asteroids

Ultraviolet and visible photometry of asteroid (21) Lutetia using the Hubble Space Telescope

Ultraviolet Spectroscopy of Asteroid (4) Vesta

Unbiased Inclination Distributions for Objects in the Kuiper Belt

Unbound or Distant Planetary Mass Population Detected by Gravitational Microlensing

Undisturbed Mesosphere Optical Properties from Wide-Angle Frequent Twilight Sky Polarimetry

Unprecedented accurate abundances: signatures of other Earths?

Unstable Planetary Systems Emerging Out Of Gas Disks

Upper limits for undetected trace species in the stratosphere of Titan

Upper Limits on the Number of Small Bodies in Sedna-Like Orbits by the TAOS Project

Upsilon Andromedae b in polarized light: New constraints on the planet size, density and albedo

Uranus and Neptune: Shape and Rotation

Using Kepler transit observations to measure stellar spot belt migration rates

Using Kuiper Belt Binaries to Constrain Neptune's Migration History

Using Satellites to Probe Extrasolar Planet Formation

Using Star Spots to Measure the Spin-orbit Alignment of Transiting Planets

Using Stellar Densities to Evaluate Transiting Exoplanetary Candidates

Using the Sun to estimate Earth-like planets detection capabilities II. Impact of plages

Using the Sun to estimate Earth-like planets detection capabilities.I. Impact of cold spots