The Solar System
Planetary Educational Resources
Mercury is the closest planet to the sun and is the smallest planet in the solar system ever since Pluto got categorized as a dwarf planet. It orbits the sun once every 88 days and has an apparent magnitude of -2.o to 5.5. In spite of the respectable apparent magnitude, the planet is not easily seen from earth due to its lesser quotient of greatest angular separation form the sun. The physical framework of the planet is similar to the Earth�s moon, heavily cratered and has no atmosphere. Mercury has an astoundingly dense due to its large iron core. The surface temperature on the planet ranges from -180 to 430 degree centigrade.
Venus is the second closest planet to the sun and in the night sky only the moon surpasses it for brightness. Venus is similar to Earth in terms of size, gravity and composition and hence commonly referred to as the �sister planet�. Venus is veiled in a dense reflective cloud of sulfuric acid which has long prevented the surface form being seen from outer space. The atmospheric pressure on the planet�s surface is about 93 times stronger than that of the Earth.
The third planet from the sun and in terms of diameter, mass and density is the largest planet in the solar system. The planet is estimated to have formed 4.54 billion years ago and is home to millions of species. As of now it�s the only place in the solar system where life is known to exist.
The fourth planet from the sun named after the roman god of war and popularly referred to as the �red planet�. Mars has a thin atmosphere with a surface that is reminiscence of the moon, peppered with craters, volcanoes and deserts. The planet is the site of the highest mountain in the solar system, Olympus Mons. Mars has a rotational period which is pretty much similar to that of the Earth. There has been much speculation about the presence of liquid water on Mars�s surface.
Jupiter is the fifth planet from the sun is the largest planet in the solar system. The planet is a massive ball of gas and is almost two and half times larger than all other planets in the solar system combined. Together with Saturn, Uranus and Neptune they make the Jovian planets.
Saturn is the sixth planet from the sun and is named after the Roman God Saturnus. The planet features a prominent set of rings, comprising of icy particles, small rocks and dust. Sixty planets orbit the planet of which Titan is the largest.
Uranus, the seventh planet from the sun is the fourth most gigantic planet in the solar system. Uranus features an internal atmosphere that is different from the other gas giants in that it contains higher proportion of water, methane and ammonia.
Neptune is the eight and the most distant planet from the sun. Neptune is the fourth largest in terms of diameter and third largest in terms of mass. Named after the Roman God of sea, it was discovered by mathematical calculation rather than normal observation.