The Sun takes 230 million years to orbit the Milky Way once. That is one galactic year. Enter any number of years and see how much of the galaxy's calendar you have covered.
Look up on a dark night. The Milky Way is a smear of light across the sky. It is also a clock. The Sun is orbiting the center of that galaxy at about 828,000 kilometers per hour. One complete lap takes roughly 230 million years. Astronomers call that a galactic year. The galaxy is the slowest clock you will ever be measured against.
If you are 30, you have lived 0.00000013 galactic years. Your entire life — school, jobs, love, coffee, everything — is a little less than one frame of the galaxy's movie. A single breath in a year-long film. The Sun, by comparison, has been running laps since before life crawled out of the sea. It has completed about 20 orbits since it formed. Earth is about 20 galactic years old. Life on Earth showed up around the 8th galactic year. The dinosaurs died 0.29 galactic years ago — the galaxy has barely turned since T-Rex went extinct.
The universe itself is 13.8 billion years old. That sounds ancient. In galactic years, it is 61. The whole story of everything — from the Big Bang to your phone — fits in 61 slow turns of a cosmic wheel. And in those 61 turns, our Sun is on lap 20, a teenager by galactic standards, halfway through its life.
Here is the unsettling part: the galaxy does not care about your lifetime. It will spin 230 million times more before the Sun dies. Every galaxy year you witness is a fraction so small it does not round. And yet — you are the only one of those frames that gets to watch. The galaxy makes the movie. You are the audience.
One orbit of the Sun around the center of the Milky Way. It takes about 230 million years. Astronomers call it a "galactic year" or "cosmic year." The Sun is currently about 20 galactic years old.
About 61. The universe is 13.8 billion years old, and one galactic year is 230 million years. Divide and you get roughly 60. The Milky Way itself formed only a few galactic years after the Big Bang.
66 million years ago, which is 0.29 galactic years. The asteroid hit just under a third of one Sun-orbit ago. In cosmic time, T-Rex is recent enough that you could argue we are still living in the aftermath.
No. The Sun's orbit is not perfectly circular, and the galaxy is not a perfect disk. The value varies between about 225 and 250 million years. Also, galaxies in other parts of the universe spin at different speeds — some take over a billion years per lap.