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On March 22, 1997, a super-bright comet called Hale-Bopp made its closest approach to Earth. It was bright enough for people to see without telescopes or binoculars for more than 18 months.
Comet Hale-Bopp still holds the record for being visible to the naked eye for longer than any other comet, and was probably the most-seen comet in history.
It passed Earth at a safe distance of about 120 million miles before continuing its orbit around the Sun.
As it approached the sun, Hale-Bopp's two blue and white tails grew larger and brighter. By the time it reached the sun on April 1, it was outshining all the stars in the sky except Sirius.
Check out the full series "This day in space".