Our Solar System

Mankind has always been making discoveries about the celestial bodies that surround us. The solar family is a blend of opposites – of unimaginable giants, of hundred metre asteroids, of extremely hot lands and of freezing cold atmospheres. So, who are these members journeying around the sun?

OUR SOLAR SYSTEM

The solar system consists of the sun and other astronomical bodies orbiting around it under the influence of its gravitational field. These celestial bodies include the planets, their satellites and meteorites. While satellites revolve around their planets, and the planet around the sun, it is intriguing to note that the solar system too, keeps revolving around the nucleus of Milky Way at a distance of about 30,000 light years. So, what is a light year? To analyse astronomical distances the units that we come across daily viz., metre, foot are extremely inadequate. Instead, imagine the distance light could travel in a year when it can cover 30,00,00,000 m in a second! As the name says, this is what is termed as a light year.

The sun, which has a diameter that can fit hundred and nine earth-sized bodies, is the ultimate fuel for life on earth. Contrary to the popular belief that the sun is a stationary star, it moves with the solar system at a spectacular speed of 828,000 km/hr!

What seem to be merely floating about the Sun, are not just some spherical masses of various sizes. Unique in their own way in almost every aspect, these distant bodies have kept people right from the ancient times to the modern ages wondering about their veiled mysteries, giving rise to fascinating mythologies and startling scientific discoveries.

MERCURY VENUS

Mercury, the planet closest to the sun is a god of trade in Roman mythology. (Doesn’t the name sound similar to ‘merchant’?) Venus, though resembles the Earth in many ways, is highly uninhabitable – it has a dense atmosphere of carbon-dioxide and sulphur brought about by extensive volcanic activity.

MARS JUPITER

The red planet Mars, is usually associated with wars and masculinity in mythologies. Mars has the same colour as that of rust. Can you now guess what could be the compound behind its brilliant hue?

While planets closer to the sun, namely, Mercury, Venus, Earth and Mars are ‘terrestrial’, the outer planets, Jupiter, Saturn, Neptune, and Uranus are actually ‘gas’ giant. (Pluto is no more considered a planet now.) In fact, the ringed-planet Saturn is so gaseous that, it is buoyant enough to float on water! (No, Jupiter sinks!) The answer lies in Archimedes’ Principle. The hint is, Saturn’s average density is 0.7g/cm³ and Jupiter’s is 1.4g/cm³.

SATURN

Accompanying these planets, we have a belt of asteroids located roughly between Mars and Jupiter. These bodies have no regular shape and can have mean diameters of more than 400km.

URANUS NEPTUNE

Uranus, the god of the skies in Greek mythology, has an almost horizontal axis of rotation! Neptune is a near-twin to Uranus. This was the first planet to be ‘mathematically predicted’ from unexpected changes in Uranus’s orbit.

- Article by Akshay Nemande

- Edited by Vaishnavh