I’m planning to live for about 80 years.
In that time, the Earth will orbit the Sun 80 times.
In turn, the Sun will orbit the centre of the Milky Way (our galaxy).
This will take 230,000,000 years.
About three million lifetimes. Nine million generations.
In the entire history of modern man, we’ve barely started an orbit.
Our galaxy doesn’t orbit anything. But then, the Universe is only 13,700,000,000 years old. Maybe we just haven’t had a chance to get started.
The atoms in our bodies are elements that can only be created in supernovae – exploding stars. Going by the quantities we have available, we’ve probably been through two supernovae.
Hot gas gathers into a ball of fire, nuclear explosion, drifts apart, gathers into clouds, collects into ball of fire, nuclear explosion, drifts apart, gathers into clouds, collects into ball of fire. Our solar system.
Our sun is about 5,000,000,000 years old. The previous stars from which we’re made were bigger, and the universe was smaller and hotter, so they didn’t last as long. We can last another 5,000,000,000 years before we have to start looking for a new one. Our sun won’t explode – it will just fizzle out.
The heavens move, but our lifetimes are just a beat of the hummingbird’s wing.
Our nearest neighbour is 4 light years away. Not so far, at the speed of light. Of course, we can’t travel at the speed of light. We can mathematically prove that we’ll never be able to come close. One light year is 6,000,000,000,000 miles.
The stars are unreachable.
Despite all our advances in science and technology over the last century, it still takes an immense amount of power to lift anything into orbit. And mere words can’t convey the scale of the power required. These are the biggest machines mankind has ever created. They burn simple chemical fuels; no atomic power is used.
The problem of getting into orbit is still an engineering challenge, not a scientific challenge.
From orbit, where can we go? The moon is nearby, for want of a better word. It’s a rock.
Venus and mercury burn so hot, they’re unapproachable. Mars is an arid desert. We can no more populate that than we can the heart of the Sahara.
The gas giants are so distant that they’d take years to reach, and are incredibly dangerous. Jupiter’s magnetic field is so huge that it’s tearing the moons apart. The winds of Saturn orbit once every ten hours – that’s thousands of miles an hour,
There is nowhere for us to go.
Space is a beautiful, fascinating light show, forever beyond our reach.
If you’re interested in space, you should sponsor my friend Chris’s project for Astronomers Without Borders: reach for the stars.