The Space Station Crosses a Spotless Sun

Explanation: That's no sunspot. It's the International Space Station (ISS) caught passing in front of the Sun. Sunspot s, individually, have a dark central umbra , a lighter surrounding penumbra, and no solar panels . By contrast, the ISS is a complex and multi-spired mechanism, one of the largest and most sophisticated machines ever created by humanity . Also, sunspots occur on the Sun , whereas the ISS orbits the Earth . Transiting the Sun is not very unusual for the ISS , which orbits the Earth about every 90 minutes, but getting one's timing and equipment just right for a great image is rare. Strangely, besides that fake spot, in this recent two-image composite, the Sun lacked any real sunspots . The featured picture combines two images -- one capturing the space station transiting the Sun -- and another taken consecutively capturing details of the Sun's surface. Sunspots have been rare on the Sun since the dawn of the current Solar Minimum , a period of low solar activity. For reasons not yet fully understood, the number of sunspots occurring during both the previous and current solar minima have been unusually low .