Multi-epoch observations of the β Pictoris b exoplanet. The planet was imaged in 2003 (left image) in the L' band (3.8 μm) in the plane of the circumstellar disk surrounding the star (not seen here). It was detected again October 2009 (middle) when it had moved to the other side of the star. The new observations made March 2010 at 2.18 μm are shown in the right panel. The planet has moved yet again relative to its position measured in 2009. Astronomy & Astrophysics