Happy in the Long Distance Relationship!?

 If the Sun were even a tad different, if it were even a little bit more or less active, or smaller or bigger, or a little farther or closer, there won’t be life as we know it.

Perfect distance Earth-sun relationship!

Life is totally dependent on the Sun. The proximity decides the temperature of the planet. If Earth were farther, it would be too cold to hold life, and if it were nearer, it would be too hot. Not only it decides temperature, but also the amount of radiation hitting the surface of the earth. Like we put UV protecting sunscreen, and trees get cooked in hot tropical summers, if the radiation is more, all types of life will be affected.

 When the sun is in the later stages of life, millions of years later, excess radiation would affect the earthlings severely. One of the suggestions is to spread some absorbents in the stratosphere, as it would happen after a volcanic eruption or nuclear war! But that’s in a far future. And, as it would be an eventual rise in the amount of radiation and temperature, the species will evolve accordingly, if they survive!

Earth as seen from the space

If the Earth were not solid, but a gaseous planet like Jupiter, the life as we know it, would not be sustained. For terrestrial life, the soil is an essential component. The soil contains macro and micronutrients. The process of accretion and formation of planets had led to the formation of these elements essential for life. These are the most crucial part of the day-to-day chemical processes that make life possible, and they come in the food chain from the soil.  

It is a lucky coincidence that our earth has an atmosphere and it is made of 78% nitrogen, 21% oxygen and 1% other gases. This cocktail ensures that there is enough oxygen for life to survive, but not too much that everything goes on fire. The atmosphere also maintains the temperature owing to the greenhouse effect. It also filters solar radiation and saves us from severe sunburns. The activities that we consider quite basic, like talking and listening, or flying, or seeing birds in the air, will not be supported if not for the air.  

Fortunately, most of the asteroids are attracted by the planet Jupiter because of its strong gravitational field. The asteroids which come towards earth don’t reach the surface most of the times, because while entering the atmosphere they face the air resistance and burn down. This saves the life from any external impact.

The magnetosphere of the earth: saving us
 from solar winds and activity

Curious scientists have been looking for life on other planets. They define habitable zones as the range of orbits around a star where the planets can hold liquid water depending on the atmospheric pressure. It is this very special Earth-sun relationship that has led to the possibility of sustainable life. Arthur C. Clarke has said very aptly, “Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”

The habitable zone: Not too hot, not too cold!

The stellar wind and activity affect the planet’s space weather in different ways. The solar activity leads to the beautiful phenomenon of aurorae. But it also affects the satellite communication. It interferes with the signals, stops the satellites from working and in extreme cases, it fries the machinery in the satellites. These winds, if stronger, they could also affect life. The magnetic field of the earth also plays an important role in saving us from these frantic attack of ionised particles. 

The Coronal Mass Ejection

 It is important to understand the stellar activity in order to predict the possibility of life on the planets revolving around that star. The stellar activity would influence the temperature, radiation, constituents and elements on the planet, possibility of atmosphere and many more factors. Understanding the relation between stellar activity and these factors determining the possibility of life would be the first step in looking for alien life. Because as Carl Sagan said in Contact, “The universe is a pretty big place. If it's just us, seems like an awful waste of space.”