Wonders of the Solar System

The Blue Planet-Earth! Blue because of the life sustaining liquid water in abundance. It’s a perfect ‘Goldilocks’ planet. Neither too hot, nor too cold and even better with its thick atmosphere and perfect ratio of gases. Above all, it supports life right from micro organisms to the mammoths. It is the reason we are all here. Then there are nature’s creations that intake carbon dioxide and sunlight and make their own food-the plants. Earth is the third of eight planets of our Solar system and is simply perfect! This is indeed the biggest and most fascinating wonder of the Solar System (and the Universe as much as we know it today).

The others may be not-so-perfect, yet they are enchanting, appealing and posing several open questions. Flowing with the laws of physics known and unknown, these are striking in all sense! While every planet still holds plentiful mysteries and abundant wonders, there is at least that one special feature which cracks us up! These are to me the wonders of the Solar system. The first one mentioned above. The Planet Earth with the perfect distance, spin, atmosphere, liquid water, and life definitely makes it to the top of charts. 

Mercury, the Roman Messenger God, having a year of less than three Earth months, is extreme! It is closest to the Sun, smallest yet dense. With no significant atmosphere, it has extreme temperature rise during the day and extreme drop during the night. The lack of atmosphere is also responsible for the intense battering the tiny planet faces. Mariner 10 first gave us close insight about Mercury and now it is the MESSENGER orbiting, mapping and revealing the secrets. Mercury is scarred, heavily cratered. The giant Caloris Basin, spanning 1550 kilometres is the most distinct geological feature on this little planet and is one of the largest multi ring impact basins in the solar system. 

Venus, the Roman Goddess of Love (I'm sure no woman would want to be from Venus) is hellish with its thick carbon dioxide clouds, toxic sulphuric acid and killing atmospheric pressures. It’s sluggish-a day on Venus lasts 243 Earth days (for all those who complain of 24 hours being too less should have a day out here) and spins retrograde. Well, it isn't all that bad! It’s the brightest one (and hottest) around! The greenhouse effect is one of the most extreme process happening here. It is what makes it the hottest planet-thick cover of carbon dioxide. You need RADAR eyes to penetrate this envelope. And beneath it you would see rolling plains, highlands, plateaus, lava plains and many (tens of thousands) volcanoes making Venus (courtesy the missions). The morphological range varies from huge Venusian shields to pancakes to coronas.

When it comes to the highest mountain volcano in the Solar System, it has to be Mars, the Roman God of War.  The Olympus Mons (over 25 kilometres) stands much taller than Mt Everest. The volcano would be something to look at! And if that wasn't enough spectacular, there is Valles Marineris, the longest (about 4000 km long) and deepest (2-7 km) equatorial canyon system. Still not enough? It has large impact basins- Hellas and Argyre! Mars is reddish due to the oxidized or rusted iron-rich minerals. Mars has valleys, volcanoes, canyons, fractures, craters. It experiences seasons and growing and receding ice caps. It is frequented by dust storms lasting for months, has huge ancient flood plains, gullies, channels. It is now being studied by a robot geologist-Curiosity. Evidence for liquid water and life remain the prime questions. With these remarkable features, Mars must be a geologist’s paradise!

Jupiter-the King of Roman Gods. It looks handsome, most massive (much massive than all planets put together), and superlative at a glance, true to its name, it never fails to impress. The Lord of the Planets has dozens of moons (60 +) at its behest. It has the shortest day in all planets (less than ten hours). Beautiful well segregated atmospheric bands are seen as latitudinal zonation. Its planetary atmosphere is the largest spreading. Hydrogen, hydrogen and more hydrogen and some Helium are the key constituents of it. The Great Red Spot is the grandest feature of Jupiter. Huge enough to engulf the Earth, it is an anti cyclonic storm persistent since few centuries.  Jupiter also has the strongest magnetic field in all planets. This gas giant with number of moons revolving around resembles a diminutive solar system! 

Well, well well, Saturn can’t be left behind when you speak of the wonders. If Jupiter is the Lord, Saturn is the Queen. Its beauty is awe-inspiring and colour stunning golden yellow. Blessed with the rings, they only add to its beauty. One can never forget the first time they watch Saturn through the telescope. It’s addictive. None of the planets have the complicated and glorious ring system as Saturn, it comprises of rings, ringlets, spokes of ice, dust, rock debris, fragments tiny and large.  Cassini has given us many extraordinary images from this ringed planet. Interesting fact: It’s less dense than water, so it would float given a HUGE tub! Saturn is sheer grace, absolute beauty. 

Uranus, the ice giant, isn't all that bland as it would seem. It’s dynamic and mysterious! Strong winds, bright clouds, ring system, seasonal variations, irregular magnetic field, large moons and small ones-that and much more! William Hershel is the discoverer of this planet. In fact the story of discovery of the planets Uranus and Neptune is in itself astounding. Its blue green hue (absorption of red) is because of the methane in its atmosphere along with hydrogen and helium. It appears toppled on one side (probably due to a collision in its early history) and rotates east to west.  Voyager 2 revealed many details about Uranus which were till then unexplored. And to remember the names of Uranus moons, thou art to read the Shakespeare’s plays! 

The smallest of the gas giants and the eighth planet of our Solar System-the intense azure Neptune, the Roman God of Sea, was on look out ever since the discovery of Uranus and subsequent detection of gravitational perturbation. Again, we owe a great deal to Voyager 2 flyby for particulars about Neptune. Very high speed winds (supersonic) prevail in the weather system of Neptune making it dynamic and varied. These are often sustained for a longer duration. Taking about 165 years to orbit the Sun, Neptune has completed only one orbit (in 2011) since it was discovered. Due to the strange elliptical orbit of the dwarf planet Pluto, Neptune sometimes goes beyond Pluto (for 20 years of 248 years).  The Great Dark Spot is the famous anti cyclonic storm detected on Neptune during the Voyager flyby, large enough to swallow the Earth which died out over time. Neptune too has a ring system. Neptune is cold and dark and yet many features remain unknown.

So what makes all the planets so unique? Why is it that all planets have evolved so differently? Negligible atmosphere on planet one, thick atmospheric cover on another, liquid water and booming life on next, a 25 kilometre volcano on red planet, then the gas giant, the rings making another one most breath taking, the ‘spinning-like-top’ planet, the supersonic winds on the last body we call as planet in the solar system! From dense surface of one to no surface at all! From no moons of a planet, to irregular moons, to more than 60 moons of another! From red to blue to azure planets! 

Posing more questions than solutions, this is the harvest of curiosity!

P.S: There can never be enough said about them. But these are just a few of the absorbing things we would get hooked to, to know more. And when so much is said about the planets, I should do justice to speak about their companions-their satellites too! Stay tuned!

**Figures, numbers, for orbit, rotation, revolution source NASA