Length of day

The length of the day is how long a day is. On Earth, a sidereal day is 23 hours and 56 minutes long, and a solar day is 24 hours. There are other planets with different types of day.

 Length of the day on other planets 
This uses Hours time and days on earth.Enchanted Learning.com
 Mercury - about 1,416 Hours/59 days
 Venus - 5,832 hours/ 243 days
 Earth - 1 day
 Mars - about 1 day, 0.6 hours
 Jupiter - 9 hours
 Saturn - about 10 hours
 Uranus - about 13 hours
 Neptune - about 15 hours

 Increasing day length on Earth 
The Earth is constantly losing angular velocity and rotational energy through a process called tidal acceleration, which leads to a slow lengthening of the day. Tidal acceleration is an effect of the tidal forces between an orbiting natural satellite (e.g. the Moon), and the primary planet that it orbits (e.g. Earth). This is adjusted by leap seconds.

A century ago, the average day was about 1.7 milliseconds shorter than today.McCarthy D.D. & Seidelmann P.K. 2009. Time: from Earth rotation to atomic physics. Weinheim: Wiley-VCH, pp. 88–89 In the late Neoproterozoic about 620 million years ago a day had only about 21.9±0.4 hours.

 Related pages 
Sidereal day
Rotation period

 References 

 Other websites 
 Day -Citizendium

Category:Days
Category:Earth sciences