Vesta and Ceres, measuring 326 miles (525 kilometers) wide and 590 miles (950km) wide, respectively, are too small for observers to spot surface details using earthbound telescopes. You can, however, locate these bodies and track their positions. All you need is an up-to-date ephemeris, a sketchpad, a pencil, and binoculars or a scope.
NASA’s Jet Propulsion Laboratory made available a limited Web-based interface to its HORIZONS system, which provides solar system data and accurate ephemerides that you can tailor to specific observing dates and locations. Just head online to http://ssd.jpl.nasa.gov/horizons.cgi.
As luck would have it, both asteroids are currently viewable in the constellation Virgo the Maiden. (See “View Ceres and Vesta at their best” on p. 52.) Opposition (when an object lies opposite the Sun in our sky) occurs April 13 for Vesta. Around that time, it is visible to the naked eye at magnitude 5.8. Only two days later, Ceres brightens to 7th magnitude.