Talerra is the world on which my terrestrial campaign is based. As such, the material presented here is but a fraction of my ever-growing collection of notes and scribbles. The information below is geared towards Spelljammer campaigns, glossing over the day to day, groundling activities.
Talerra is an average-sized terrestrial world. It has enough axial tilt to produce seasons, and a magnetic field to allow the use of a compass for navigation. The planet's surface has young mountain ranges—and the rare volcano here and there—surrounded by lush forests, dense jungles, open planes, arctic tundras, and so on. Oceans, in the form of salt water, cover more than three-quarters of the planet.
Talerra's moon is a dry, inhospitable place. From Talerra, it appears as a silver disk, bringing the sun's reflection to a cold night. Its radius is over one quarter that of Talerra, and it is the second brightest object in the sky. The moon is tectonically dead, and has no magnetic field. It's also a desert; no surface water can be found anywhere, making cloud cover nonexistent. The temperature on the moon's surface ranges wildly from searing heat during the day to well below freezing after sunset. This rapid change creates strong, dusty winds in the moon's thin (treat as fouled) atmosphere. Anybody caught unprotected out in the open will have difficulty breathing.
The moon's surface is covered with tall, jagged mountains which jut up like bony-fingers pointing to the stars. These mountains range in height from several hundred yards to several miles, but have bases smaller than one quarter this distance. They are spread out uniformly over the entire surface, ranging yards to miles apart. The space between the mountains is filled with a fine dust "sea". This dust is very difficult to walk on. Anybody attempting to move about on this "sea" will sink up to their knees. There are patches of dust which are less dense than their surroundings, causing creatures to sink deeper—sometimes over their heads. (If this happens, follow standard suffocation rules.) Rafts and boats could be used to get around this, though normal, sea-going vessels will sit very high (due to the density of the dust) and may tip over.
It is not known how the mountains were formed as the planet is geologically dead, though evidence suggests a great catastrophe. One possibility is that the moon was once a much larger, hollow world which collapsed in upon itself. Whether any life existed and/or survived is unknown. Whatever the catastrophe was, it had an effect on the moon beyond changing its shape: magic doesn't function well on the surface. This effect extends out a few miles into space. (Treat spellcasters as being three levels lower for the purposes of determining a spells affects. If level is less than that required to cast the spell, then it cannot be cast.) Only a handful of explorers have been on the surface over the millennia, and none have tried any excavation.
Though uniformly boring and unpleasant, the moon does have one point of interest. On a relatively smooth section near the base of an unusually tall peak are the remains of a small ship (treat as 5 ton cog). Next to the wreckage is the well preserved corpse of an elderly human wearing robes. Inside the ship's only room is his diary and spellbook along with some spoiled food and water. The diary documents the wizard's journey into space from Talerra over a century ago, using a combination of Levitation and Fly spells, and his new Fast Travel spell. Together, these spells allowed him to leave Talerra's atmosphere and travel to the moon, where his ship failed due to the moon's weak magic. His spellbook contains various spells appropriate to a 14th level wizard, including Fast Travel.
The Fast Travel spell allows the caster to enchant a vehicle with the ability to travel great distances very quickly. It only works in space away from large gravity wells—same requirements as needed for a normal helm to attain spelljamming speed. It allows the ship to travel 100,000 miles per day. This is only fast enough to get a ship to the moon or a nearby planet in the inner system, but it doesn't make a mage lose all his spells. Fast Travel provides no other locomotion—the ship either flies quickly or doesn't move at all. Other forms of propulsion—like Levitate or Fly spells—are required to leave the atmosphere.
The material components are feathers from a swallow's tail, a vial of quicksilver and two loadstones.
