Another ALMA antenna takes its place at Chajnantor

The tenth ALMA antenna arrives at the 5000-metre Chajnantor plateau in March 2011, carried on an ALMA transporter vehicle, joining eight others in the central cluster. Another antenna is not shown here, as it is placed about 600 metres away, allowing the astronomers and engineers to test the system���s performance with a longer baseline ��� the separation between a pair of antennas. When ALMA construction is completed in 2013, there will be a total of 66 antennas in the array.