NASA has announced the fourth opportunity for scientists around the world to propose for observations using the NuSTAR X-ray space telescope. This Guest Observer (GO) Program is part of an extended mission plan approved by NASA that offers observing time for basic research investigations selected in a competitive process. Proposals for observations to be made within the four cycle of the NuSTAR GO program are due on Jan 19, 2018. Click through for more information.

To celebrate the fifth anniversary of NASA's NuSTAR space mission, the mission's lead scientist, Fiona Harrison of Caltech, talks about some of her favorite images.

A collection of images from NuSTAR's 2nd Birthday celebrations around the world.