A stunning photo shows the International Space Station caught passing directly between the Earth and the sun.
The remarkable composite image, which was taken by photographer Rainee Colacurcio, was selected as a NASA Astronomy Picture of the Day.
Even though the ISS is far closer to the Earth, the orbiting laboratory is still dwarfed against the immense surface of the sun in the background.
Ms Colacurcio took the image from Edmonds Beach in Washington.
‘That’s no sunspot. It’s the International Space Station (ISS) caught passing in front of the Sun,’ said Ms Colacurcio.
‘Sunspots, individually, have a dark central umbra, a lighter surrounding penumbra, and no solar panels,’ she added.
‘By contrast, the ISS is a complex and multi-spired mechanism, one of the largest and most sophisticated machines ever created by humanity.’
‘Transiting the Sun is not very unusual for the ISS, which orbits the Earth about every 90 minutes,’ Ms Colacurcio added.
‘But getting one’s timing and equipment just right for a great image is rare.’
In fact, this great picture is a really a combination of two images — one of the space station as it passed in front of the Sun, and another taken at the same time that captured details of the Sun’s surface.
The resulting composite pictured is also unusual for how it shows the Sun lacking any real sunspots.
These are darker patches that appear temporarily on the surface of the Sun and represent regions of relatively cooler temperatures thanks to localised magnetic fluxes which dampen convection.
The number of sunspots at any given time tends to vary with the 11-year solar cycle.
‘Sunspots have been rare on the Sun since the dawn of the current Solar Minimum, a period of low solar activity,’ Ms Colacurcio explained.
‘For reasons not yet fully understood, the number of sunspots occurring during both the previous and current solar minima have been unusually low.’