Red planet, the Mars(1)orbit and physical

 In the sky, there is a star that brights red. It is planet, the Mars.
In the 1920s, people believed Martians are exist. Because people think the Mars' canyon a canal. But Martians(that we can saw) don't exist. But once a go, many scientists think that life  lived in the Mars. Presence of Martian attract many people's curiosity. Let's learn about Mars' characteristic. The Mars is so exciting, so there will be 2or3 posts about Mars.

1.Mars' orbital characteristic
The Mars is about 1.6AU from the Sun.(http://travelingcosmos.blogspot.kr/2013/12/bodes-law.html
Mars is located in goldilocks zone, but it is too cold. It's orbit is almostly ellipse. It's orbit isn't simillar to circle.


Aphelion:249,209,300 km(1.665 861 AU)
Prehelion:206,669,000 km(1.381 497 AU)

The Mars' orbital period is less than 2 times of 1 year. Mars' day is called "sol" Sol is simillar to 1 day.

Orbital period:686.971days
Rotation period:24h 37m

2.Mars' physical characteristic

Mars' land is simillar to the Earth, but Mars is much smaller than the Earth.

Mass:6.4185×10²³ kg(0.107 Earths)
Volume:1.6318×10¹¹ km(0.151 Earths)
Surface area:144,798,500 km²(0.284 Earths)Polar Radius:3,376.2 ± 0.1 km(0.531 Earths)
Euqatorial Radius:3396 km(0.533 Earths)
Mean density:3.9335  g/cm³
Surface gravity:0.376 g