It is a refreshing fact that the prospects for human survival are substantially higher if we live on two worlds, instead of just Earth. The moon, say, or Mars… every extraterrestrial body poses unique technical challenges to colonization. Yet nearly all are at least potentially habitable – in theory. Our survival prospects climb higher for three worlds, higher still for four. The more worlds we colonize, the more likely a colony on at least one of them will still exist at any given future moment. It’s like flipping quarters: the more you flip, the greater the chance at least one will come up heads.
Last time: the Martians. This time: Half a Planet is Better Than None
Half a planet is better than none. You might not have heard of Ceres (pronounced like “series”), but it exists - in the asteroid belt between Mars and Jupiter. Though large by asteroid standards — it is the largest — it is officially classified as a ‘dwarf planet.’ With a diameter of 590 miles it is indeed dwarfed by Earth’s 7,920 miles, or thirteen times as much. Surface area is more relevant to colonization than diameter, however, and just as a foot has 12 inches but a square foot has 12×12 or 144 square inches, the surface area of earth is 13×13 or 169 times greater than that of Ceres. Yet, if you stood on its surface it certainly wouldn’t feel small. Geometry tells us that to a person standing on the surface, Earth’s horizon is only a little more than double Ceres’. That’s enough to give a similar sensation of distance, even though this dwarf planet is so much tinier than Earth.
On the other hand, other facts of day-by-day life on Ceres are downright out of this world compared to our experiences on mothership Earth. The Cerean day is a minute or so longer than its rotational period of 9 hours, 4 minutes and 27 seconds. (Similarly, Earth’s 24-hour day is 3 minutes 56 seconds longer than its rotational period of 23 hours, 56 minutes and 4 seconds. The Earth is orbiting around the sun at the same time as it spins around like a top. After spinning around exactly once, the Earth has also moved to a slightly different spot in its orbit, so the sun’s light comes from a slightly different direction, lighting up a slightly different half of the Earth. This has the effect of delaying sunrise on average by that 3 minutes 56 seconds.) Since a Cerean day is just a few minutes over 9 Earth hours, for convenience the Cereans may define their hour so there are exactly 9 of them in a Cerean day. The tiny difference between an Earth hour and a Cerean hour (half a minute) would be imperceptible.
Life with days of 9 hours would be an interesting experience. A circadian sleep-wake cycle within that time frame is probably ridiculous, but a 3-day (Cereans call it a “triday”) cycle of 27 hours might work nicely. You would rarely have trouble getting up, since the 27 hours compared to Earth’s 24 means that getting up late by Earth’s standards would still be early on Ceres, so you could get a few extra things done before leaving for work. And with everyone living in a bubble, the commute would be shorter too. The following typical schedule will help you prepare for your move (courtesy Ceres Bureau of Tourism and Immigration).
Table. Typical Cerean resident’s schedule.
6:00 a.m.: Morning sunrise. Jump out of bed if not already up (gravity is low, and you are well rested).
9:00 a.m.: Arrive at work.
9:59 a.m.: The hour only goes up to 9, unlike 12 on Earth, so in another minute it will be 1:00.
1:00 m.d.: Ante-midday (a.m.) period transitions to midday (m.) period.
1:30 m.d.: Midday sunset.
3:00 m.d.: Firstlunch.
3:30 m.d.: Back to work.
6:00 m.d.: Midday sunrise.
6:30 m.d.: Secondlunch.
7:00 m.d.: Back to work.
9:59 m.d.: Work will be over in another minute.
1:00 p.m.: Work over. Transition to post-midday (p.m.) period. Go home.
1:30 p.m.: Evening sunset.
5:00 p.m.: Bed time. You’ve been up 17 hours, and the Ceres Bureau of Health notes that it is easier to fall asleep while it is still dark. Your Earth-evolved 24-hour clock is perpetually trying to catch up to the Ceres 27-hour triday cycle, making you sleepy by now, yet alert by the time to rise. You are ready to begin 10 hours in bed. (Bureau of Health Memo 3862B suggests 9 hours of sleep out of 27 is commonly adequate, and provides suggestions for the remaining hour for those seeking guidance on the matter.)
6:00 p.m.: Nighttime sunrise. You are asleep.
9:30 p.m.: Approximate time to begin meditative wakeful state (was called “watching” on Earth before artificial lighting became common).
9:59 p.m.: One more minute before it is 1:00 a.m.
1:00 a.m.: Transition into a.m. period. New calendar date starts.
1:30 a.m.: Nighttime sunset. End roughly hourlong “watching” period and go back to sleep.
6:00 a.m.: Sunrise. Jump out of bed again if not already up.
Very low gravity. With gravity only about 1/36 Earth’s, things are different indeed. Try this now: jump just hard enough to get an inch off the ground. On Ceres, that would get you about 3 feet up. Can you jump a foot? On Ceres you’d fly up 36 feet (or hit the ceiling). Walking around, one would tend to bounce off the ground with each step, which might resemble a flying leap more than a step. Running would be effortless and fast. It would probably feel a lot like flying. For the grueling around-the-world trek that groups of young Cereans (called “trekkies”) take before being welcomed into adult society, they are trained to swing a long trekking pole at the ground, the tip hitting obliquely at about 20 miles per hour. This propels the youths forward at that speed (see notes), and up enough so their feet never touch the ground. Indoors, one would need to walk in a more controlled fashion, without pushing downward against the floor more during some parts than other parts of the average step, because that would tend to send you flying upwards, potentially making it hard to stop before careening into the nearest wall or even hitting your head on the ceiling. To walk the Cerean way, push backwards against the floor without any extra downward push, using your gluteal (buttock) muscles to “pull” your heel backward with each step. The trick is to not push off with the front of your foot. Try it! It feels odd at first here on Earth but, with a just a little practice, you’ll be ready for your Cerean adventure.
Extraterrestrial terrorism. Terrorists and gunslingers on Ceres could create a form of chaos not possible on Earth. Bullets could be fired into orbit. Where the orbit brings them nearly to the surface, they could actually hit an innocent bystander years after they were fired. There is no atmosphere to slow them down! Earth firearms work on Ceres. Muzzle velocities vary depending on type of gun. Some firearms cannot launch a bullet into Cerean orbit, while others fire a bullet so fast that instead of orbiting it escapes the gravity well of Ceres entirely and flies off into space. For intermediate power guns, the true velocity can be made more or less than the muzzle velocity by firing in the direction Ceres rotates, or against it, or some other direction. By the same principle, rockets here on Earth are often fired near the equator because the ground is moving eastward (which is why the sun rises in the east) around the South Pole-North Pole axis fastest there, and that gives the rockets a speed boost. Thus, fired carelessly or maliciously, many guns could put a bullet into an orbit that comes arbitrarily close to the surface.
Recently, a youth on trek nearly lost her life from an orbiting bullet! People talked about it non-stop for weeks (since normally, nothing happens on Ceres). She jumped up only ten feet (equivalent to jumping up about 3 inches on Earth), and an orbiting bullet punctured her space suit, grazing an elbow. Fortunately other youths in the party responded quickly, heroically patching her space suit before too much air was lost, then using a special tourniquet to temporarily apply pressure to the injury through the suit. While the trek is the bridge to adulthood on Ceres, no one wants such heroism to become necessary. Guns aren’t much use on Ceres anyway, except staple guns.