Pronunciation: (SEE-uhr)
Star system: Sol
Distance to Sol: 197,000 miles
Radius: 1,145 miles
Surface Area: 16.5M square miles
Volume: 6.3B cubic miles
Circumference: 7,190 miles
Moons: Cara, Fain, Fiach

Siur is the second planet in orbit around Sol, sharing its orbit with Terra, an arrangement which cause Terrans to consider Siur to be a sister planet

From the perspective of sentient terran humanoids, Siur is the source of alot of speculation. In a roughly opposite orbit, Siur remains a similar distance from Terra throughout the year. It has similar appearance and size to Terra, leading to beliefs that Siur has abundant water, and potentially plant, animal, and possibly even humanoid life. Siur is considered to be a “sister” planet to Terra