Venus crescent phase about one month before or after inferior conjunction. Venus fades to about magnitude −3 when it is backlit by the Sun. The planet is bright enough to be seen in a clear midday sky and is more easily visible when the Sun is low on the horizon or setting. As an inferior planet, it always lies within about 47° of the Sun. Venus "overtakes" Earth every 584 days as it orbits the Sun. As it does so, it changes from the "Evening Star", visible after sunset, to the "Morning Star", visible before sunrise. Although Mercury, the other inferior
Solar power in Spain The Andasol 1 power plant went online in November 2008, and has a thermal storage system which absorbs part of the heat produced in the solar field during the day. This heat is then stored in a molten salt mixture and used to generate electricity during the night, or when the sky is overcast. A 15 MWe solar-only power tower plant, the Solar Tres project, is in the hands of the Spanish company SENER, employing molten salt technologies for receiving and energy storage. Its 16-hour molten salt storage system will be able to deliver power around the clock. The Solar