关于一年的定义是一个星球围绕太阳旋转一周需要的时间。而一天是这个星球自转一周所需要的时间。

The scientific definition of a year is the amount of time it takes for a planet to make one revolution around the Sun. Earth’s neighbouring planet, Venus, takes 225 Earth days to revolve around the sun. The definition of a day is how long it takes for a planet to do one complete rotation on its own axis. It takes Venus 243 Earth days to do this. In other words, a day on Venus is longer than a year on Venus. The rotation of Venus on its axis is retrograde. It rotates in the opposite direction of Earth and the other planets in the Solar System (Uranus spins on its side).

The main interesting fact in this report is that Venus’s day is longer than its year.

The scientific definition of a day is the amount of time it takes for a planet to do a full rotation on its axis.

The report mentions Uranus because it is another planet that spins on its axis in a unique way. Venus spins backwards and Uranus spins on its side.