Jupiter's strong gravitational pull has allowed it to retain most of its original atmosphere. The planet's gravity prevents gases from escaping into space. Jupiter's immense size and mass create enormous gravitational forces that bind the atmospheric gases to the planet. Additionally, Jupiter's lack of a solid surface means there is no crust or lithosphere to absorb or release gases into the atmosphere. As a result, Jupiter has been able to retain a substantial portion of its original atmosphere over billions of years.