In a statement, the USPS noted this mission of ensuring security applies to the Cluster Box Units (CBU) as well. “Postal Service guidelines specify that the purchase, ...

In this week's Astronomy magazine podcast, we'll help you observe the Northern Jewel Box (NGC 6231), globular cluster M12, and the Bug Nebula (NGC 6302) in your July night sky.

Overview of Cluster Box Units. The audit sampled 78 individual CBUs from a total of 14,697 unique CBU addresses served by the Beechnut, Debora Sue Schatz, and T W House Stations in Houston, TX.

Previous surveys of single galaxy clusters have taken several months using existing instruments, says Carlstrom. “My group has measured about 60 clusters in a decade,” he says.