The photograph above shows the International Space Station (ISS) against the fiery backdrop of our Sun. Without a sunspot to speak of, the ISS stands out against this strangely uniform background as the only blemish on the star's surface, because we're currently in a solar minimum - a deeply quiet phase of the Sun's 11-year cycle.
The dazzling picture, taken in broad daylight by photographer Rainee Colacurcio, shows just how insignificant in size the ISS truly is. Using a dedicated hydrogen-alpha solar scope, which can help us view the Sun in all its blazing glory, Colacurcio managed to catch a glimpse of the ISS at the precise moment it passed between Earth and our Solar System's magnificent centre.
Appearing like a dark splotch in the corner of the disk, the station's H-like silhouette can barely be made out against the burning background. And while it may look like a sunspot at first, it's far too uniformly dark to be mistaken for one. (Sunspots have a dark central umbra, followed by a lighter penumbra ring surrounding it, and obviously this is the ISS, not a sunspot).
Pictures like this one are quite hard to manage. As the ISS orbits Earth every 90 minutes, the station's passage across the Sun has to be perfectly timed. In this case, the image was put together using two photos that were taken simultaneously: one of the space station transiting the Sun, and the other of the Sun's surface.
Source: Science Alert.com CARLY CASSELLA 26 July 2019
Image at Top: courtesy Rainee Colacurcio, via APOD