rating: +26+x

by Rigen

Item #: SCP-6669

Object Class: Keter

Special Containment Procedures: SCP-6669 and SCP-6669-1 are subject to STRL-class academic censorship. Booster probes are to be dispatched whenever necessary to keep SCP-6669 instances hidden behind suitable trans-Neptunian objects, this is considered priority Tau for Outer Solar System division.

In the event that additional SCP-6669 instances are detected approaching the Sol system, emergency deployment of disposable probes is authorized to divert the instances away from the Sol system.

Investigation into SCP-6669-1 is to be assigned priority Sigma for the Department of Extrasolar Activities.


Approximate locations of SCP-6669 instances relative to inner Sol system objects, accurate to J2000 epoch.

Description: SCP-6669 are massive solar sails, measuring larger than 100 kilometers in diameter, suspending an oblong payload approximately 1 kilometer long and 300 meters in diameter. Spectral analyses have determined that the objects are coated in reflective alumina layers on every surface, but exposed underlying material cannot be conclusively analyzed by current technology. There are three known instances of SCP-6669 in the Sol system, designated SCP-6669-A, -B, and -C. All of these instances are situated within the heliopause1, approximately 120 AU from Earth. All attempts to communicate with these instances have been unsuccessful.

SCP-6669 instances carry large collections of dormant and active microorganisms within their payload, all capable of either thermosynthesis or radiosynthesis utilizing energy and nutrients emitted through unknown means from its core. Analysis of data obtained through scans and samples from micrometeorite cracks suggested that these microorganisms are capable of consuming a large breadth of material to support their complex internal ecosystem. It is hypothesized that if an instance of SCP-6669 is to be allowed to survive an impact or land on a suitable celestial body, these microorganisms would begin to convert the celestial body into a functional biosphere, presumably ideal for habitation of SCP-6669's creators.


[REDACTED] star. Bright object to the upper right is irrelevant.

SCP-6669-1 is a megastructure of presumed alien origin, located in [REDACTED] star system, ███ parsecs from the Sol system. SCP-6669-1 is comprised of a toroidal structure estimated to be at least 600 kilometers in diameter, and a cylindrical launch facility in its center measuring in excess of 1000 km.

Approximately once every 3 years, instances of SCP-6669 are launched at near-light speed from the launch facility towards indeterminate targets. It is currently unknown how SCP-6669-1 chooses the target for these launches. Given the velocity of these launches and the construction of SCP-6669 instances, it is unknown whether any of their payloads could survive an impact with their targets or reasonably slow down to land using their sails alone. While SCP-6669-C was prevented from entering the Sol system by the Foundation, it is currently unknown why and how SCP-6669-A and SCP-6669-B failed to cross the Kuiper belt into the inner Sol system.

Due to its distance, contact with SCP-6669-1 is currently impossible. Should the object attempt to make contact with human civilization, or should humanity expand in its direction, it would likely result in Scenario G-87 (Alien Thought Process, Mostly Peaceful) of Theoretical Human-Interstellar Civilization Contact Catalogue.


Foundation astrophotography of SCP-6669-A and SCP-6669-B prior to 1990.

Discovery: Prior to the launch of the Hubble Space Telescope in April 1990, the Foundation had only been aware of SCP-6669-A and SCP-6669-B instances as trans-Neptunian objects with unusually high albedo. The images and measurement captured from Hubble Space Telescope, and later Foundation Exospheric Nanosatellite Imaging system, confirmed that the instances are in fact further, and thus larger than previously thought. The newly formed Outer Solar System division was immediately tasked to research and conceal these instances.

On January 20██, SCP-6669-C was detected approaching the Sol system by the Observatory for Relativistic and Luminal Anomalies. Emergency deployment of experimental probe equipped with Diminished Inertia Controlled Kinetic Energy Transducers was authorized to break the instance and prevent it from entering the inner Sol system. The probe succeeded in safely braking the instance into less than .001% the speed of light, preventing its entry to the Sol system. The instance then deployed its solar sail from its folded state.


Artistic rendition of SCP-6669-C unfolding its solar sail. Proportion of the payload has been exaggerated.

Using the data acquired from observation of SCP-6669-C, Predictive High-Interest Object Monitoring System calculated the trajectory it took and traced it back to the [REDACTED] star system, where subsequent observations detected the existence of SCP-6669-1.

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