The two spring dates

Before the invention of calendars and other modern methods of tracking years and seasons, people relied on the position of the sun in the sky and obvious signs in nature to indicate the passing of time.

When the equator and the hemispheres of the Earth became common kn...

As mars orbits the Sun, it completes one rotation every 24,6 hours, which is very similar to one day on Earth (23.9 hours). Martian days are called sols—short for "solar day." A year on Mars lasts 669.6 sols, which is the same as 687 Earth days.

Mars' axis of rotation is tilted 25 degrees w...

1. Write a To-do list with all the items on your agenda today
2. Analyze which tasks can be completed quickly, in less than two minutes
3. Create a new list in the order of completion time
4. Schedule tasks that take a longer time to complete for later