Item #: SCP-900
Object Class: Keter
Special Containment Procedures: SCP-900 must be contained in the center of a circular Ridley Magnetic Shell(RMS) at all times. The RMS SCP-900 is contained in is surrounded by a larger RMS, in the event that the smaller RMS should fail so personnel may fix the inner RMS. If both shells fail a one thousand six hundred (1600) megaton nuclear warhead which is positioned above SCP-900's containment cell will be detonated immediately. SCP-900's containment cell is locked and guarded by a team of eight (8) armed guards. Anyone approaching SCP-900's containment cell below Level 5 or Class D clearance is to be terminated on sight. No exceptions. Any and all study on SCP-900 is to be done through security surveillance cameras.
Description: Nicknamed "Ragnarok's Comet" by personnel, SCP-900 was first discovered orbiting Jupiter in 19██. SCP-900 is a large comet composed of several lunar minerals and unknown metals, and many large shards of diamond. SCP-900 is also composed of several combustible and explosive materials. SCP-900's dangerous threat was realized when NASA noticed SCP-900 breaking off from Jupiter's orbit and heading towards Earth. NASA notified SCP, and the NASA and SCP personnel discovered upon analysis via satellite that SCP-900's composition was identical to the remains of the meteor that caused Incident 924, also known as Tunguska. A team was immediately dispatched, disguised to the public as a manned trip to [DATA EXPUNGED]. The team successfully contained SCP-900 using an RMS. SCP-900 was discovered in the process to be three point one four (3.14) times larger than the Incident 924 meteor. SCP-900 was then transported to the ████████ ████, and Site 17 was built around it, where it currently resides. Since it was contained successfully with a magnetic field, it has been determined that all of SCP-900's metals are magnetic, but extraterrestrial. It's also interesting to note that SCP-900 [DATA EXPUNGED] every other [DATA EXPUNGED] for (15) fifteen minutes.
A matter of high distress is SCP's explosive composition. If SCP-900 touches any other matter the explosive materials in it can combust and will set off it's power. The level of it's power is estimated to be [DATA EXPUNGED].
Destruction of SCP-900 is not planned, unless both RMS fail, using the aforementioned technique. Tampering with SCP-900 could cause a worldwide catastrophe.
Addendum: Note from Dr. Fraen to Site 17 personnel
It is of the utmost importance that SCP-900's containment never fail. Should SCP-900 even touch the Earth, due to it's unusual fragile composition, it could cause another wide-spread extinction of all mammals. This is the least thing we need. Take the utmost care of 900.
Addendum: Possible cause of SCP-900's orbit towards Earth
Approximately ██ days after SCP-900 was contained, an abandoned observatory was discovered near ██████████. Inside, personnel found a magnetic device, a telescope aimed toward Jupiter, several documents about Incident 924, several documents in an unknown language, and a diagram of SCP-900's orbit. Personnel believe that the owner(deceased) was going to weaponize SCP-900.