Sunday, September 13, 2009
Ceres has for too long been thought of as simply being a large asteroid, and along with this most are not even aware of its existence. This is a pity because not only is Ceres a fairly large world of its own worth exploring, but it may be a better location than Mars for human colonization, and it's this nearly complete lack of knowledge about the (dwarf) planet that keeps it from being discussed in the public sphere as a destination for human exploration as is the case with the Moon vs. Mars.
Even when the diameter of Ceres is known it still doesn't mean all that much. It has a diameter of 950 km or so, but since diameter doesn't mean much when trying to visualize the grandeur of a celestial body, this once again doesn't mean much. What is important is surface area, and even better is a comparison of the surface area compared with locations we know here on Earth.
On that note, here are two images of Ceres (not a real image since we are still lacking in images from up close; this is from Stellarium) with some cities from Europe and the US (plus Canada) in order to show just how much there is to explore on Ceres. Each one of these is only one half of its surface area so all the cities could fit inside. The scale is quite rough but still accurate enough to give an idea of how much room there is to explore and develop on the surface of the planet.
As you can see, Ceres has a surface area that easily encompasses a number of well-known countries, and the total population that could comfortably live there (looking at surface area alone) is easily a few hundred million. Certainly not just a big asteroid. In fact, when Ceres was first discovered it was categorized as a planet (that's why it has a planetary symbol of its own), and it wasn't until later that it was demoted and largely forgotten.
The Dawn spacecraft will arrive at Ceres in 2015 so when that happens there will certainly be a great deal of attention paid to Ceres, but hopefully it will be possible to begin discussing it as a possible destination even before then, which will not only build anticipation for Dawn's arrival but also hopefully influence policy - a rover mission to the surface would be the next logical step after Dawn, and perhaps if the decision is made to begin exploring near-Earth asteroids before the Moon we will begin thinking about other alternative destinations as well, including Ceres. The Moon is naturally still the easiest target after a near-Earth asteroid, but if manned missions to Mars are to be debated then there's no reason to not include Ceres as well. After all, launch windows are much more frequent:
and it apparently has more ice water within it than all the fresh water on Earth.