Home Sweet Home
According to the Earther calendar, the date is March 21, 2392.
324 Bamberga. Why are we on the sixteenth largest asteroid in the main belt? Starhawk picked it. He said he would feel safe here because “It's big, but not one of the really big ones, so no one should bother us”. I think he just liked the name. I like it because it's as near as I can get to home – Mars – Gongen. Of the million asteroids with a diameter greater than a kilometer, we ended up on this medium-sized one. If you add up the mass of all of them it would not quite equal the mass of Luna. As long as it's safe and will allow us to plan, organize, store materials, and recruit, I think I can call it home – for a while. It's going to be a long road, and a tricky one, before we can convince our ignorant and arrogant peoples into forming the proper alliances, and force the eventual peace we have in mind. We had to establish a base as soon as possible. We chose the interior of this asteroid, to attract as little attention as possible. Work is progressing very slowly.
Mining was tough at first. We didn't want a halo of rocks and dust orbiting the asteroid. We didn't want to fly through that every time we lifted off or landed, so we had to avoid tossing up debris from the mining machines. Gravity here is extremely low, and it could take weeks for a casually kicked rock to land, so we had to erect a large rip-stop tent around the base before we started. The entrance to our sanctuary, and thus the beginning of our excavations, is in the deepest valley available. We hope the surrounding “hills” will provide some shelter from the coming storms.
Fortunately, Bamberga is a low density asteroid. At 1.8g/cm3, it is less dense than the Dwarf Planet Ceres (2.05g/cm3 ), and her sisters, Pallas (4.2g/cm3) and Vesta (4.3g/cm3). It is about a third as dense as Earth - near 5.5g/cm3, the highest in the Solar system. That makes it easier to mine since its materials are less well packed. Plus it has natural cavities that we are able to exploit. The ground here is mostly stable, but not consistent. Some regions are porous and easily broken, like volcanic ash. Other places are rich in metals, the ores containing the raw materials we will need later. There is another reason not to jettison materials as we mine them. We refine the rocks as we go. They take up less volume in their purified states, so the overall mass of this place does not change, and we have a ready supply of many useful substances. Even small amounts of water can be extracted, but not enough.
When we first arrived, it was eerie to stand topside and see this dark world curve away from us in every direction. It looked like we were on top of a mountain, but if we would walk in any direction, we would never actually get “down”. Growing up on Gongen, watching adventure vids, I got the impression that the Asteroid Belt was a dangerous place that could only be traversed by experts or madmen. Nothing could be further from the truth. We rarely get close enough to another sizable rock to be concerned. We know they are there, and we track them as we come and go, but they are easy to avoid because they are so spread out. Much more likely threats are pebble-sized, but they are present throughout the solar system. We take standard precautions and have had no problems with them.
How do we walk? Very carefully. On the surface it can be done, but only with training and patience. Since a 200lb person would weigh less than 1/3 of one pound when standing on the surface, most situations require the use of smart-jets. They give a small push on the top of your feet to keep you gently fixed to the ground. They activate when your feet are close to the ground, so you can even walk up cliff-faces if gravity is low enough. It's not a perfect system. It forces you to waddle like a duck and balance on one foot while relocating the other foot. It is slow and tiring, because you must fight against the thrust of the miniature rockets until you can pull your foot at least 10cm away from the surface. This asteroid has a mass of about 1.1X10^19kg and thus a surface gravity of only 0.014 m/s². If you jump off of a 1m high platform, it will take you 12 seconds to reach the ground. If you are standing on the ground and carefully jump up 0.25 meters in a controlled manner, it will take 12 seconds to get back to the floor. If you are careless enough to forget and you push as if you were on Earth, you will end up almost 1240m above the surface of Bamberga, and it will take you more than 14 minutes to get back down.
On the interior, we have other techniques. On a smaller asteroid that might spin faster, we would smooth the surfaces that face topside, and take advantage of the spin by walking with our feet toward the outside. If you walk fast enough, centripetal force would be much greater than gravity and you would be able to get from place to place with little difficulty. This technique is almost impossible for us to use, even in corridors that are parallel to the surface, because Bamberga spins so slowly – once every 1.23 Earth days. Instead we are making two varieties of corridor. Corridors between adjoining rooms will not generally need to be large, so we are making them straight, smooth and narrow, so we can use our hands and feet to maintain our position. In emergencies, we could simply launch ourselves at the far end and hope our aim is true. Larger corridors will be bored to specific “rooms” that will eventually house equipment, machinery, and larger necessities. Starhawk's people have developed a type of three-tracked vehicle that acts as an elevator and crane for large packages. Each chamber will be hemispherical to provide several advantages. This shape is easy to bore out of the interior of the asteroid, and creates large floor spaces without needing any extra ceiling support. Plus the roof can act as an extra walkway and allow for very tall shelves. We can't use spherical rooms because there IS some gravity. In a spherical room everything would eventually "fall" to one small section of the room. One must simply push off of the floor while in the right position to begin walking around on the vaulted ceiling. So when we run around the inside of one of our rooms, there is not much difference between the outer side and the inner side. It's almost as if our home isn't rotating at all. The deeper we bore, the less gravity there is. That is the other reason we began our project in the deepest valley we could find – so we would start out as close to the center as possible.
There are other benefits to being here. Bamberga does occasionally get close to Gongen because of its high eccentricity. At perihelion it's only 1.775 AU's from the sun. At aphelion it goes out to 3.591 AU's. Mars generally resides around 1.5 AU's. With its long year (4.4XEarth) we will be in a window to make a quick trip “down” to Gongen twice per Bamberga year and 4 times for Earth. The escape velocity is a mere 0.23 km/s (one fiftieth that of Earth's). It is difficult to comprehend, and even more difficult to sense, but our average orbital speed around the sun is less than 19 kilometers per second. We must rocket ahead or Bamberga and accelerate to more than 23 kps to rendezvous with Gongen and almost 30 to meet with Earth. However we must fly retrograde and slow down to “climb” up to Jupiter's orbit. Nature's ironies never cease to amaze.
Because we are about 2 AU's from Sol, it is only one fourth as bright as it would appear from Earth. That makes the night sky even more beautiful than I could have dreamed. The atmosphere of Gonden and Earth and their proximity to our home star combine to block out most stars. When traveling in a ship there are moments when you can see the uncountable stars, but those moments are fleeting. Since we rotate about once every 1.226 Earth days and have positioned our observation room on the "equator", we have a long slow night almost 15 hours long, full of stars.
We can risk leaving here about once every 30 sleep cycles. We must stockpile water, food, tools and weapons. The first several weeks were the hardest since we had to live on the ship until the first “rooms” were complete. We had to purchase air purification and re-breathing systems, but we were able to fabricate our own heater systems. Without these, the average temperature, 172K (-101oC), would make things more than a bit uncomfortable.
I miss Gongen. Going from a world half the size of Earth to a rock with a diameter of 230 kilometers takes some getting used to. It does not seem to affect Starhawk. He has lived much of his life on moons and aboard ships. When I look out into space, Earth and Gongen/Mars are both fairly bright at the moment but that changes from month to month. I wonder if either my family or perhaps my sensei ever look up at this rock. Why would they? This rock is not conspicuous, moving slowly across a background of stars. A child looking through a telescope might think this was a star, but every astronomer's computer can tell him that it is not so far away after all. I do not want my people to know that I am here. Not yet.
Bamberga is both a C-type and a P-type asteroid. It is carboniferous and metallic with low albedo. This it not actually a good thing. Because of its low reflectivity, our activities may be more obvious than they would be on a bright world, so we must be extra careful with engine flares and other energy emissions.
Obviously we couldn't go to Ceres. That's the busiest part of the asteroid belt. It is the biggest asteroid by far and the only truly round one. Fortunately, we have friends that do have access to its water supplies. Ceres, a G-type asteroid with a 4.6 year orbit, has as much ice as Earth has fresh water, so the relatively small amounts we purchase may not catch anyone's attention.
I was taught in history classes that Ceres was discovered on January 1, 1801, and was classified as a planet, as were 2 Pallas (B-type protoplanet), 3 Juno (S-type) and 4 Vesta. As soon as astronomers realized that there were perhaps millions of asteroids, it was demoted and for almost 100 years, the solar system was back to having 8 planets. Although Pluto became planet number 9 for the better part of a century, early in the 21st century they reclassified Pluto and Ceres as Dwarf Planets. Ceres is so useful today, that the distinction doesn't matter. Pluto, on the other hand, is still useless.
It was Herschel that first coined the word Asteroid, right?
We thought about going to Vesta. That would have been a purely symbolic gesture because the Earthers are so afraid of the debris from Vesta. Many NEAs seem to be from old Vesta impacts. Although there is plenty of room in Vesta to make a home, we opted for a more secluded area.
Kirkwood gaps... (when plotting orbital periods vs number of asteroids) There are gaps in the main belt. At those distances from the sun the period (according to Kepler's 3rd law) would be in resonance with Jupiter and thus affected by Jupiter's gravitational pull greatly, thus eliminated from that distance, eventually.
Based on spectra which has to do with surface content... C-group (contains C-type, B-type and G-type) type carbon S-type silicon X-group (contains M-type metal)