UNIVERSE 

The combination of space and time 

The universe includes planets, stars, galaxies, and all other forms of matter and energy. While the spatial size of the entire universe is unknown,it is possible to measure the size of the observable universe, which is currently estimated to be 93 billion light-years in diameter. In various multiverse hypotheses, a universe is one of many causally disconnected constituent parts of a larger multiverse, which itself comprises all of space and time and its contents.