Grapefruit-Sized Vanguard 1: The Silent Oldest Satellite Still Orbiting Earth

Vanguard 1, launched in 1958 and about the size of a grapefruit, remains the oldest human-made object in Earth orbit; its radio transmitters ceased in 1964, but it continues to circle the planet, helping scientists study orbital dynamics and Earth's shape, with NASA estimating an orbital lifetime of about 240 years (re-entry around 2198) though the date is not precise.