The phrase "sufficient gravity" refers to a situation or event that is serious or important enough to be taken seriously and treated with importance. Full definition
They typically lack sufficient gravity to retain an atmosphere. (discovermagazine.com)
Otherwise, there wouldn't be sufficient gravity in the cluster to prevent the hot gas from escaping. (science.howstuffworks.com)
Section 750 of the Criminal Code is a reflection of Parliament's intention to prevent individuals who have committed offences of sufficient gravity from continuing their employment with the public service. (mackenziedrs.com)