The study of astronomy in Gielinor started in the Fourth Age when Scorpius started to study the stars. He built himself a telescope and started to use the stars for divination, naming the constellations as he researched. He had an apprentice named Phyrrys. After he fell in with some Zamorakian worshippers, his work was destroyed by the kings of Ardougne. A grave was constructed in his memory just north of the Observatory, and it is here that you can speak to the Spirit of Scorpius. More history of Scorpius can be found in the Astronomy book.
The biggest telescope is on the top floor of the Observatory, which must be repaired during the Observatory Quest before being used. Its design is based on that of Scorpius, and it is currently run by the Observatory professor and Observatory assistant. Through it, players can view some of the constellations in the sky. On the walls of the lower floor in the observatory are some charts which show the 12 standard astrological constellations. (i.e. Capricorn, Aquarius etc.) There is also an Orrery in the Observatory reception, which is where players can find the Astronomy book.
Player-owned house studyEdit
Several pieces of astronomical equipment can be built in the study of a player owned house including telescopes, globes, orreries and astronomical charts. Players can use the telescope to look for Shooting Stars during the Distraction and Diversion.
Players can navigate by the sun using a Sextant, Chart and Watch. Coordinates are given in degrees and minutes, with the Observatory being the centre at 0 degrees north (equator) and zero degrees east (meridian). This is used in level 2 and 3 Clue scrolls in Treasure Trails.
The Mahjarrat hold their Ritual of Rejuvenation every 500 years, during a celestial event called a syzygy, when all the planets align. This has seemingly no magical significance, however, and it only serves as an easy way to identify when the ritual takes place. Several past rituals took place without the syzygy, and it was Wahisietel who first suggested to use it after hearing of it from human astronomers.
The villagers at Witchaven also seem to be waiting for a particular celestial alignment as they will tell you "Soon now... So soon. The stars are almost right."
Solar system of GielinorEdit
In the solar system of Gielinor, there appears to be two planets orbiting a star.
The inner planet in the orrery is light blue and its moons are grey. Calculated using the Large orrery's movements, the inner planet's year is about 1.75 seconds. The planet has two moons. One of which circles the planet in 0.5 seconds while the other revolves in 0.75 seconds. Assuming this planet is Gielinor which has an orbit of 365 days, the first moon's orbit is 104 days (0.5/1.75=0.29 years) long. The second moon's orbit is 156 days (0.75/1.75=0.43 years) long.
The light blue outer planet is twice as big as the inner planet and its moon is grey. Calculated using the Large orrery's movements, the outer planet's year is about 4.8 seconds and its moon orbits in 0.9 seconds. This means that the outer planet's year is about 1001 days (4.8/1.75=2.74 years) long and that its moon orbits in about 188 days (0.9/1.75=0.51 years).
There are some controversial theories based around known facts and this model.
Some people believe that one of the two planets is the area known as ScapeRune. ScapeRune is considered the opposite of RuneScape or Gielinor. Little is known about the location of ScapeRune, so it is possible. Critics counter that ScapeRune is a parallel universe because in a parallel world things are depicted as an opposite.
It is not known which of the two planets is ScapeRune, but many suggest that the small inner planet with two moons is ScapeRune because RuneScape only has one known moon. The smaller size would explain why RuneScape is larger than ScapeRune. Critics counter that the small inner planet should be RuneScape because it has the standard anti-clockwise orbit like Earth. If RuneScape is the outer planter, then it should be the one that is opposite. Either way, the opposite orbits explain why ScapeRune is opposite of RuneScape in most aspects.
The spherical shape of the orreries suggests that Gielinor is a sphere, no matter which of the two planets it may be. The map of RuneScape may at first suggest that RuneScape is flat. This is confirmed by the Unknown areas of RuneScape. When approached, the Unknown is a large black abyss. However, these are only areas where ships haven't travelled yet. This situation can be compared to the history of Earth which was at one time considered flat until exploration proved it spherical. The most accepted theory states that RuneScape is a sphere and that "The Unknown" on the east and west sides of Gielinor connect to make a large ocean similar to the Pacific Ocean on Earth.