November 12, 2009
You must need patience to work on Europe’s Rosetta comet mission. Launched in 2004, the spacecraft won’t arrive at its main destination, Comet 67P/Churyumov-Gerasimenko, until 2014. That’s longer than New Horizons is taking to get to Pluto. The reason is that it requires a lot of energy to meet up with a comet orbiting at five times Earth’s distance from the Sun. In fact, Rosetta has had to repeatedly pump up its energy by making three close swings past Earth and one past Mars.
Tomorrow morning comes the last of these gravitational boosts: Rosetta will pass within 1500 miles of a point above the Indonesian island of Java at about 8:45 a.m. European central time.
The picture above is Rosetta’s most recent view of Earth, returned just today from a distance of 393,000 miles as the spacecraft approached our planet.
But I prefer the beauty below, taken during the probe’s last visit exactly two years ago. It isn’t often that you see both the color sunlit crescent (bottom) and the lights of Earth’s cities at night.