As of now, The International Space Station (ISS) is the Largest Man Made artificial object in the Sky.
The ISS maintains an orbit with an altitudeof between 330 and 435 km (205 and 270 miles). It completes 15.54 orbits per day and is one of the most visible space objects from Earth. Below is a long exposure photograph of the Space Station crossing the sky.
The ISS could be so bright at times, it becomes brighter than Venus - the brightest object we see in the sky apart from the sun and the moon. The below picture indicates the moon and ISS - ISS is the bright object (Dot) to the left of the moon.
Additionally, the spotting the ISS crossing the disk of the Sun and the moon also can be described as phenomena that one should not miss.
The passes of the ISS over a given Geographic location could be calculated and informed to the public.
Below is a video of the ISS passing over land.
NASA also provides a 24x7 live feed from the ISS - Enjoy the view of earth from space below.
Enjoy the sky watch !