Item #: SCP-5060
Object Class: Euclid
Laconic Containment Procedures: It can't be contained physically since it's in space so just monitor it with Foundation probes and suppress the public's awareness of it.
Laconic Description: SCP-5060 is a planet in orbit around the star HD 4560 inhabited by hostile aliens that periodically ejects moon-like bodies into space every few years. These satilites are 50km wide, hollow, and contain balls of various powdered elements inside.
One day a bunch of projectiles hit the Earth from space and are found to be those satilites but with previously-lost Foundation probes in their centers instead of powdered elements. The Foundation tracks their trajectory and finds these satilites were ejected from Venus, implying that the aliens are also present in our own solar system.
Additional Context: SCP-5060 was an entry in the SCP-5000 Contest, where it won 15th place.