The international space station (ISS) is the biggest satellite ever made by human (109x73x28 meters). It can be easily seen with the naked eye on the night sky as a bright object travelling among the stars. Although its complete orbit takes around 90 minutes, it takes only approximately 5 minutes to cross the local night sky.
In a daytime it's generally not possible to observe the ISS, because the sky is too bright due to the Earth's atmosphere. And very rarely the ISS crosses the sky in the position where the Sun is located at this moment. This is what we call the ISS Solar Transit.
In the following pictures, taken by astronomers of the CESAR project from ESAC, you can see the Sun's chromosphere shadowed my a silhouette of the ISS. Even though the ISS was, at the time of the transit, in a distance of 1150 km from ESAC, the shape of its majestic solar panels is easily visible.
Please remember that observing the Sun is safe only when using a special telescope equipped with a tested solar filter.
