Space
Jupiter's Great Red Spot is a storm larger than Earth that has raged for at least 190 years.
The spot has been observed continuously since 1831, and possibly since the 1660s. Wind speeds around its edge reach more than 400 kilometres per hour.
Why is this true?
Jupiter has no solid surface to create friction and slow storms down, so they can spin for centuries. The spot has been shrinking for decades, and no one knows for sure how long it will last.
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More about space
Space facts are mostly a lesson in scale. Days longer than years, storms wider than Earth, light that left its star before the pyramids existed — the numbers stop being intuitive very quickly. Every entry here comes from established astronomy and includes a short explanation of what causes the effect, so the fact holds up when someone asks the obvious follow-up question at the dinner table.