How do you feel when you look into the sky at night?
Fascinating! isn’t it? Especially when I was a child, I used to wonder a lot about those bright stars visible in the sky. It spiked curiosity in my mind.
How far are they? Does anyone live there? Can we go there? These are some common questions arise in our mind in our childhood.
Unfortunately, as we grow up that curiosity dies slowly in most of us. We don’t wonder about the stars, about the space like before (unless we become an astronaut).
But these days I wonder even more about the space than in my childhood. Reading books on space and watching documentaries have filled me with inquisitiveness. I know I am not going to become an astronaut, but then who said only astronauts can learn about the space, the stars, the galaxies.
There is one more reason why I love learning about space.
If you learn about the solar system, the galaxies, the whole universe a little bit, it will make you realize how insignificant you are. You are like a tiny sand particle in a vast desert in this mammoth universe. You have no idea how big this universe is (or even probably the multiverse). Look at the image below-
This picture was taken by NASA’s Voyager 1 space probe from somewhere near Saturn planet (6 billion kilometers from the earth). The tiny blue dot you can see in the image (where ‘you are where’ is written) is the earth. That’s where we all live.
If our planet is that small even within our solar system (imagine how would it look from outside solar system) then do you think you are even observable in this universe?
This feeling itself makes me really humble and grateful towards life. You have born to live your life to it’s fullest not to worry about everything, not in your control or not to show off. Just enjoy your time as long as you are here.
Ok let me ask you a question
Do you know what is the farthest traveled (from earth) spacecraft name?
It’s Voyager 1. In 1977 NASA launched two spacecraft to study the planets of our solar system like Jupiter, Saturn, Uranus, Neptune etc. Those are Voyager 1 and Voyager 2.
How did it all start?
In 1964, a graduate student named Gary Flandro observed a rare alignment of the planets Jupiter, Saturn, Uranus, and Neptune. They would all be aligned on the same side of the sun during the 1980s. He also realized that such a configuration wouldn’t happen again for another 176 years.
There is a tremendous advantage of this. The rare alignment presented a singular opportunity to visit all four outer planets with the one mission.
The advantage was gravity assist. Gravity assist is when a spacecraft uses the gravitational force of another object, usually a planet, to alter its speed and trajectory. Due to this spacecraft can visit the planets in a much quicker time than expected.
Voyager 1 and 2 are identical spacecraft equipped with instruments like particle sensors, infrared and UV sensor magnetometer, television cameras, etc. to conduct 10 different experiments.
They’re powered by ‘radioisotope thermoelectric generators’, which convert the heat produced by the radioactive decay of plutonium into electricity.
More interestingly both spacecraft carries a golden record that contains sounds, music, and images from Earth, intended for any aliens or future humans who chance upon the craft.
Carl Sagan, the famous astronaut said the best thing about these ‘Golden record’ in his book ‘The Pale Blue Dot’-
” Perhaps the records will never be intercepted. Perhaps no one in five billion years will ever come upon them. Five billion years is a long time.
In five billion years, all human beings will have become extinct or evolved into other beings, none of our artifacts will have survived on Earth, the continents will have become unrecognizably altered or destroyed, and the evolution of the Sun will have burned the Earth to a crisp or reduced it to a whirl of atoms.
Far from home, untouched by these remote events, the Voyagers, bearing the memories of a world that is no more, will fly on.”
Voyager 2 was launched on 20th August 1977 and Voyager 2 on 5th September 1977. Due to Voyager 1’s better speed and shorter route, it is the farthest traveled spacecraft right now.
Voyager 1 took a direct path from saturn to interstellar space while Voyager 2 traveled towards Uranus and Neptune after it encountered Saturn. (See above the Voyager trajectory image).
Both of the craft gave us tremendous information about our solar planets like Jupiter, Saturn, Neptune etc. Like the presence of volcanos on Io (third largest moon of jupiter) instead of being a cold place, presence of oceans on Europa (smallest moon of Jupiter) etc. For the first time, we have observed planets and their moons so closely.
Where are these spacecraft now?
Voyager 1 entered the space between stars – ‘interstellar space’ – in August 2012, going beyond the influence of the Sun’s magnetic field and ‘solar wind’ of charged particles. This means that it’s the first man-made object ever to leave the Solar System.
Voyager 1 is 19 billion kilometers away from earth and its radio signals take 17 hours to reach us.
Voyager 2 entered into interstellar space in 2018 and it is now 18 billion kilometers away from us. It takes 16.5 hours to reach its radio signal to earth.
It’s been 42 years when both these spacecraft were launched. Still, both of these are going strong.
But by 2025, it is expected that Voyager 1 will exhaust its plutonium power supply, at which point it’ll end its broadcasts back to Earth. The same thing is expected for its twin Voyager 2 in the near future.
However, both the spacecraft will continue to travel in the space. In the next 40000 years, they might encounter another star in our milky way galaxy. Only thing is,we might not get any data from them.
Just imagine there used to be a time when people thought our planet earth is everything and the sun revolves around it. We evolved with time. We realized that the earth is just a small planet among others revolving the sun.
And today even our entire solar system looks a tiny grain compared to the universe we know.
What is waiting for us next? No one knows. But as our knowledge about the universe is increasing, it’s making us smaller and smaller. As if it’s telling us to be more humble. As if it’s telling ‘stop giving so much importance to yourself, just live your life to it’s fullest’.
So who are you in this universe?
C’mon, you are not even observable.
Have a meaningful week. Until next time