MARS: CLOSEST APPROACH 2007
In December 2007, the Mars closest approach and
opposition will occur within a week of each other.
This is an exciting time for astronomers and planetary
geologists to image and study our planetary neighbor.
On December 18, Mars will be the closest it has
been in the last two years, reaching a distance
of 55 million miles from Earth. This series of images
was taken with Hubble's Wide Field Planetary Camera
2 on December 1-7, within two weeks of its December
2007 closest approach. Each image shows the planet
rotating about 90 degrees from the next image. This
gives astronomers a full-globe look at the Red Planet.
Mars and Earth have a "close encounter"
about every 26 months. These periodic encounters
are due to the differences in the two planets' orbits.
Earth goes around the Sun twice as fast as Mars,
lapping the Red Planet about every two years. Both
planets have elliptical orbits, so their close encounters
are not always at the same distance. In its close
encounter with Earth in 2003, for example, Mars
was about 20 million miles closer than it is in
the 2007 closest approach, resulting in a much larger
image of Mars as viewed from Earth in 2003.
The planet appears free of any dust storms during
this closest approach, however, there are significant
clouds visible in both the northern and southern
polar cap regions. The resolution is 13 miles (21
kilometers) per pixel.
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA),
J. Bell (Cornell University), and M. Wolff (Space
Science Institute, Boulder)