Five facts about the Milky Way galaxy that you may not know

Did you know that the length of the Milky Way galaxy is about 100 thousand light‑years? If we could travel at the speed of light, crossing the entire galaxy would take us 100 thousand years! Currently, the fastest spacecraft is the Parker Solar Probe, and for it to traverse the whole Milky Way would require 2 billion years.

By the most modest estimates, our galaxy contains between 100 and 400 billion stars, and if you tried to count them aloud one per second, it would take more than 10 thousand years. Meanwhile, there are only about 8 billion people on Earth, so if each were given ten personal “stars of ownership,” billions of extras would remain.

Around the Milky Way swirl about 50 dwarf galaxies like tiny satellites around a huge planet. We have one Moon, Jupiter has more than 90, and our galaxy has as many as five dozen “companions.” Among them the brightest are the Large and Small Magellanic Clouds, which are visible to the naked eye in the Southern Hemisphere.

The Solar System races around the center of the Milky Way at a speed of about 828 thousand kilometres per hour. That’s like flying from Moscow to Vladivostok thousands of times in one second. One such orbit around the galaxy takes roughly 230 million years — that is our galactic year.

The Milky Way is almost the same age as the Universe. The age of our galaxy is estimated at 13.5–13.6 billion years. If you imagine the history of the Universe as a single calendar year, the Milky Way would appear in the early days of January. Earth would arise only in September, dinosaurs would walk the planet closer to New Year’s, and humans would appear in the final seconds of December 31. Our home in the Universe is far older than it seems!