Tag: science & technology

Terrestrial planets are rocky planets that are primarily composed of silicate rocks and metals. In our solar system, the four terrestrial planets are Mercury, Venus, Earth, and Mars - all located in the inner solar system. Jupiter, Saturn, Uranus, and Neptune are gas/ice giants, while Pluto is a dwarf planet.

In astronomy, Uranus and Neptune are classified as ice giants because they are composed mostly of elements heavier than hydrogen and helium, such as oxygen, carbon, nitrogen, and sulfur. Jupiter and Saturn are gas giants, and Pluto is a dwarf planet.

As of current astronomical classification, the International Astronomical Union (IAU) officially recognizes 5 dwarf planets in our solar system: Ceres, Pluto, Eris, Haumea, and Makemake. There are several other candidate dwarf planets that may be added to this list in the future.

Nicolaus Copernicus was the first to develop a comprehensive mathematical model (heliocentric model) proposing that Earth revolves around the Sun, published in his work 'De revolutionibus orbium coelestium' (1543). While Aristarchus of Samos had proposed the idea earlier, Copernicus was the first to provide mathematical predictions and a complete model.

Both Venus and Mercury have no natural satellites (moons). This is relatively uncommon in our solar system - most planets have at least one moon. Mars has two small moons (Phobos and Deimos), Earth has one, and the outer planets have many.

Proxima Centauri is the closest known star to the Sun at approximately 4.24 light-years away. It is part of the Alpha Centauri star system and is a red dwarf star. Ross 248 and Alpha Centauri are also nearby but not the closest, while Sirius A is much farther at about 8.6 light-years.

Earth is the only planet in our solar system known to sustain life, due to its suitable distance from the Sun, presence of liquid water, oxygen-rich atmosphere, and protective magnetic field. Mercury is too hot and has no atmosphere; Mars has thin atmosphere and no liquid water on surface; Jupiter is a gas giant with extreme conditions.

This tests knowledge of telecommunications technology. CDMA (Code Division Multiple Access) is a channel access method used by various radio communication technologies. The other options are either made-up or refer to completely different concepts.

This tests knowledge of mobile telecommunications standards. GSM (Global System for Mobile Communications) is the standard developed by the European Telecommunications Standards Institute. The other options are either incorrect variations or unrelated concepts.

This tests knowledge of mobile technology components. SIM (Subscriber Identity Module) is the smart card that stores mobile network identification and key information. The other options are either incorrect or refer to completely different technical concepts.