Physical Geography

Uranus is a real oddball in our solar system. Its spin axis is tilted by a whopping 98 degrees, meaning it essentially spins on its side. No other planet has anywhere near such a tilt.

The Milky Way is the galaxy that contains our solar system. This name derives from its appearance as a dim “milky” glowing band arching across the night sky, in which the naked eye cannot distinguish individual stars.

In both astrology and historical astronomy, the zodiac is a circle of twelve 30° divisions of celestial longitude that are centered upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year. Historically, these twelve divisions are called signs.

Mars is the fourth planet from the Sun and the seventh largest. The planet probably got this name due to its red color; Mars is sometimes referred to as the Red Planet as the iron oxide prevalent on its surface gives it a reddish appearance.

Comets go around the Sun in a highly elliptical orbit. They can spend hundreds and thousands of years out in the depths of the solar system before they return to Sun at their perihelion. Like all orbiting bodies, comets follow Kepler's Laws - the closer they are to the Sun, the faster they move.

The umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer in the umbra experiences a total eclipse.

The sunspots cause Aurora borealis and aurora australis, magnetic storms on the surface of the sun and polar auroras.

Eris is the largest dwarf planet in the solar system and is the largest object found in orbit around the Sun since the discovery of Neptune and its moon Triton in 1846. It has a diameter between 2,400 and 3,000 kilometres (1,490 to 1,860 miles) and is 27% more massive than Pluto.

Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. This refraction is due to the velocity of light through air, decreasing (the refractive index increases) with increased density. Atmospheric refraction near the ground produces mirages. Such refraction can also raise or lower, or stretch or shorten, the images of distant objects without involving mirages.

Jupiter’s dusty main ring system is harder to see than Saturn’s, but it’s there nonetheless. Jupiter’s largely invisible torus of ionized plasma continually being ejected from its third-largest moon Io. This ring of superheated plasma orbits around Jupiter at a staggering minimum temperature of 99,700 degrees Celsius, and drastically affects Jupiter’s magnetosphere and the other particles orbiting around Jupiter.

There are three sides to the moon that are visible to us on earth: the near side of the moon, the western far side, and the eastern far side. The side of the moon that is the most valuable is the near side of the moon since it faces the earth at all times and contains four of the five largest seas/oceans on the moon. These seas/oceans are: The Ocean of Storms (Oceanus Procellarum) - 2568 km in diameter, The Sea of Cold (Mare Frigoris) - 1596 km in diameter, The Sea of Showers (Mare Imbrium) - 1123 km in diameter, The Sea of Fecundity (Mare Fecunditatis) - 909 km in diameter, The Sea of Tranquility (Mare Tranquillitatis) - 873 km in diameter.

Geography (from Greek: geographia, literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of the Earth and planets. The first person to use the word geography was Eratosthenes (276–194 BC).

Galileo Galilei was the first to see Saturn's rings in 1610, although from his telescope they resembled handles or arms. It took Dutch astronomer Christiaan Huygens, who had a more powerful telescope, to propose that Saturn had a thin, flat ring.

Only one side of the Moon is visible from Earth because the Moon rotates on its axis at the same rate that the Moon orbits the Earth – a situation known as synchronous rotation, or tidal locking. The Moon is directly illuminated by the Sun, and the cyclically varying viewing conditions cause the lunar phases.

All the planets are satellites around the Sun. Almost every ship launched from Earth can be considered a satellite, as it is orbiting either the Earth or the Sun. Even though a space probe is going "out" from the Earth to Jupiter, it is still in orbit around the Sun, so it is still a satellite. It is certainly possible to set up a satellite so that it has a circular orbit (a circle is just an ellipse whose foci coincide). Gravity can only pull in the direction toward the planet.