The Inner Planets Mercury, Venus, earth & Mars

The Earth is divided into several layers which have distinct chemical and seismic properties (depths in km): 0- 40 Crust \ 40- 400 Upper mantle 400- 650 Transition region 650-2700 Lower mantle 2700-2890 D'' layer 2890-5150 Outer core 5150-6378 Inner core Earth Earth is the only planet whose English name does not derive from Greek/Roman mythology. The name derives from Old English and Germanic The crust varies considerably in thickness, it is thinner under the oceans, thicker under the continents. Most of the mass of the Earth is in the mantle, most of the rest in the core; the part we inhabit is a tiny fraction of the whole (values below x10^24 kilograms): atmosphere = 0.0000051 oceans = 0.0014 crust = 0.026 mantle = 4.043 outer core = 1.835 inner core = 0.09675 The inner core and crust are solid; the outer core and mantle layers are plastic or semi-fluid.

Venus Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of love and beauty. The planet is so named probably because it is the brightest of the planets known to the ancients. (With a few exceptions, the surface features on Venus are named for female figures.) Venus' rotation is somewhat unusual in that it is both very slow (243 Earth days per Venus day, slightly longer than Venus' year) and retrograde. In addition, the periods of Venus' rotation and of its orbit are synchronized such that it always presents the same face toward Earth when the two planets are at their closest approach. Venus is sometimes regarded as Earth's sister planet. In some ways they are very similar: Venus is only slightly smaller than Earth (95% of Earth's diameter, 80% of Earth's mass). Both have few craters indicating relatively young surfaces. Their densities and chemical compositions are similar.

The second is the MESSENGER spacecraft, which mapped another 30% during its flyby of January 14, 2008. MESSENGER will make one more pass by Mercury in 2009, followed by orbital insertion in 2011, and will then survey and map the entire planet. Mercury Mercury is similar in appearance to the Moon: it is heavily cratered, has no natural satellites and no substantial atmosphere. However, unlike the moon, it has a large iron core, which generates a magnetic field about 1% as strong as that of the Earth Recorded observations of Mercury date back to at least the first millennium BC. Before the 4th century BC, Greek astronomers believed the planet to be two separate objects: one visible only at sunrise, which they called Apollo; the other visible only at sunset, which they called Hermes Mercury’s crust is believed to be 100–300 km thick.[19] One distinctive feature of Mercury’s surface is the presence of numerous narrow ridges, some extending over severa l hundred kilometers. Mercury's core has a higher iron content than that of any other major planet in the Solar System, and several theories have been proposed to explain this.

Mars (pronounced /mɑrz/) is the fourth planet from the Sun in the Solar System. The planet is named after Mars, the Roman god of war. It is also referred to as the "Red Planet" because of its reddish appearance. Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and \polar ice caps of Earth. Mars is currently host to three functional orbiting spacecraft: Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter. This is more than any planet in the Solar System except Earth. The surface is also home to the two Mars Exploration Rovers (Spirit and Opportunity), the lander Phoenix, and several inert landers and rovers that either failed or completed missions. Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. These may be captured asteroids, similar to 5261 Eureka, a Martian Trojan asteroid. Mars can be seen from Earth with the naked eye. Its apparent magnitude reaches −2.9, a brightness surpassed only by Venus, the Moon, and the Sun, though most of the time Jupiter will appear brighter to the naked eye than Mars.

This image compares the larger moons and smaller planets of the solar system. Note that both Ganymede (moon of Jupiter) and Titan (moon of Saturn) are larger than the planet Mercury. Our Moon is closest in size to Io.

PLANET MOONS MOON NAMES Mercury   Venus Earth 1 Moon Mars 2 Phobos, Deimos Jupiter 62 Io, Europa, Ganymede, Callisto, Amalthea, Himalia, Elara, Pasiphae, Sinope, Lysithea, Carme , Ananke, Leda, Metis, Adrastea, Thebe, Callirrhoe, Themisto, Kalyke, Iocaste, Erinome, Harpalyke , Isonoe, Praxidike, Megaclite, Taygete, Chaldene, Autonoe, Thyone, Hermippe, Eurydome, Sponde, Pasithee, Euanthe, Kale, Orthosie, Euporie, Aitne, plus others yet to receive names Saturn 33 Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas, Hyperion, Prometheus, Pandora, Phoebe, Janus, Epimetheus, Helene, Telesto, Calypso, Atlas, Pan, Ymir, Paaliaq, Siarnaq, Tarvos, Kiviuq, Ijiraq, Thrym, Skadi, Mundilfari, Erriapo, Albiorix, Suttung, plus others yet to receive names Uranus 27 Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Puck, Miranda, Ariel, Umbriel, Titania, Oberon, Caliban, Sycorax, Prospero, Setebos, Stephano, Trinculo, plus others yet to receive names Neptune 13 Triton, Nereid, Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, plus others yet to receive names Pluto Charon TOTAL 139

End of world predictions