Universal Time (UT), adopted in 1928 by the International Astronomical Union, is the time standard used in astronomical almanacs, referencing the 0° longitude meridian (Greenwich). For high precision, ...

The coming decade will see a resurgence in lunar exploration — including dozens of missions and plans to establish permanent bases on the Moon. The endeavours pose myriad challenges. Among them is a ...

In early January the sun does not rise in Kashgar, in China’s far west, until after 10am. Across the border, in eastern Afghanistan, it rises before 7am. That difference is the greatest jump in time ...