Less expensive. The cost difference between building a roundabout and a traffic signal is comparable. Where long-term costs are considered, roundabouts eliminate hardware, maintenance and electrical costs associated with traffic signals, which can cost between $5,000 and $10,000 per year.Roundabouts are also more effective during power outages.here long-term costs are considered, roundabouts eliminate hardware, maintenance and electrical costs associated with traffic signals, which can cost between $5,000 and $10,000 per year. Roundabouts are also more effective during power outages.
THE EARTH'S MAGNETOSPHERE. The magnetosphere is the Earth's magnetic environment. The Earth is a huge dipole (2-pole) magnet. The Earth's magnetic field is probably cause by its molten iron-nickel core. This magnetic field is aligned with the north and south poles, and has reversed many times during geologic history.
The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km (31 mi) to more than 1,000 km (620 mi).he atmosphere of Titan includes an ionosphere that ranges from about 1,100 km (680 mi) to 1,300 km (810 mi) in altitude and contains carbon compounds.