Thursday 11 December 2014

Mars reaches perihelion.

The planet Mars will reach its perihelion (the closest point on its orbit to the Sun) at 8.27 pm GMT on Friday 12 December 2014, when it will be 1.38 AU from the Sun (i.e. 1.48 times the average distance between the Earth and the Sun, about 206 400 000 km). Mars has a significantly eccentric orbit, varying in distance from the Sun from 1.38 AU at perihelion to 1.67 AU (1.67 times the average distance between the Earth and the Sun, about 249 800 000 km) over the course of a 687 day Martian year.

The relative orbits of the inner planets. Wikipedia.

The orbit of Mars makes relatively little difference to the appearance of the planet from Earth; this does vary considerably over the course of a year, but is affected far more by the relative positions of the planets on their orbits (they are currently separated by about 60 degrees) than by the distance of either planet to the Sun. Nor does this variability have any notable affect on the planet's climate, which, as with Earth, is influences far more by the tilt of the planet.

See also...

Landslides on Mars typically have much greater runout distances than those on Earth, due to the planets lower gravity and thinner atmosphere. This can lead to areas of layered deposits from different landslides quite distant from the source, particularly within the larger canyons on Mars. Since it is possible to produce approximate ages for such deposits based upon the number of impact craters... Ice in Martian impact craters.                             The surface of Mars has been observed continuously by the Mars Orbiter Camera from 1997 to 2006 and the Mars Reconnaissance Orbiter since 2006. During the time that these observations have been occurring around 200 new impact craters have been observed...

The planet Mars will make its closest pass to the Earth since December 2007, coming within 92 000 000 km of us on 14 April 2014. This will make the planet a particularly bright object, visible in the night sky from anywhere on Earth in the constellation of Virgo, close to the star Spica.
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