Terrestrial planet from the original solar nebula. The Solar System has four terrestrial planets: Mercury, Venus, Earth, and Mars. Only one terrestrial planet, Earth, is known to have an active hydrosphere. During the formation of the Solar System, there were probably many more terrestrial planetesimals, but most merged with or were ejected by the four terrestrial planets. Dwarf planets, such as Ceres, Pluto and Eris, and small Solar System bodies are similar to terrestrial planets in the fact that they do have a solid surface, but are, on average, composed of more icy materials (Ceres, Pluto and Eris have densities of 2.17,
Oil and gas law in the United States for it is paid without deducting costs of drilling, completing, or operating the well. Whether or not the operator can deduct costs of treating, transporting, or marketing the oil and gas, if not specified in the lease, has been a matter of legal dispute. The traditional royalty rate for oil and gas in the United States was one-eighth (12.5 percent), although today it is often higher. Some states, such as Pennsylvania and West Virginia, have set the legal minimum royalty for private oil and gas leases to one-eighth. In an "unless-delay rental" lease, a lessee agrees to pay delay rentals