If you’ve been outside after it gets dark lately, you may have noticed the brilliant reddish star in the east. But that’s no star; it’s Mars! About every year and a half, the Earth passes Mars as they both orbit the Sun, very much like how a faster racing car on the inside track laps a slower-moving car on the outside track.

Mars will come into Opposition on January 29, 2010 in the constellation Cancer. Two days before, on January 27, 2010, the planet will have come to its closest approach to Earth during this apparition: 99.33 million km (0.66399 AU). This is not very close, as Mars will be quite close to its aphelion at the time of this opposition; the aphelion is passed on March 31, 2010. This opposition will occur during Northern Spring and Southern Autumn on Mars, so primarily observable will be the Northern hemisphere of Mars.

Jan 27, 2010
Closest approach of Mars and Earth (0.664 AU = 99.33 million km). Apparent diameter of Mars is 14.105″.

Jan 29, 2010
Mars opposition on Earth, Earth in inferior conjunction on Mars. Apparent brightness of Mars reaches -1.28 mag in constellation Cancer.

http://beautywithoutborders-mars2010.blogspot.com/

About mars opposition and the event:

http://marsprogram.jpl.nasa.gov/allabout/nightsky/nightsky03.html
http://blogs.discovermagazine.com/badastronomy/2010/01/25/hello-red-planet/