Over the last few weeks, an enormous balloon has been spotted circling Earth's Southern Hemisphere in the upper reaches of the atmosphere, sparking fears that it may be a spy balloon like the UFOs that were shot down above North America in February.
But the massive floating bubble is actually NASA's latest telescope, the Super Pressure Balloon Imaging Telescope (SuperBIT). And rather than spying on unsuspecting people below, the telescope is peering into the cosmos above in search of dark matter.
