Absolute zero is the temperature where all vibrations of molecules
would stop, and a substance would have no thermal energy at all.
That temperature can't be created, even in laboratories. Even
outer space is not quite that cold.
Absolute zero is . . .
-- negative 273.15° Celsius
-- negative 459.67° Fahrenheit
-- zero Kelvin
(Interstellar outer space is about 3 Kelvin.)