I think the scientific languaje in de document is a little off.
The description says "Is a comet tha appears in the solar system…" when it should say "is a comet like object currently orbiting the sun in about the same orbital path as Jupiter".
"SCP-5469 maintains a stable orbit around Jupiter" means that its orbiting Jupiter; not the sun. It should say that it's orbit is stable and normal outside of demanifestation events.
The information on demanifestation events is a little vage; Footnote N° 2 saying that the SCP vanishes and reappears at January first means that it happens yearly? How long does it takes to demanifest and reappear? is it inmediate?, It's called"orbital speed". Jupiter's is about 13.07 km/s, so the SCP's should be about 26.14 km/s.
I don't really understand its melting phase. you need more specific numbers: Once it resets opposite side from Jupiter, how much mass does it have, what does "melting" means, does the comet heats up? at what rate does it desintegrates?
If by "rotation" you mean "lap around the sun", then it should say "revolution".
If the object is around 14.000 years old, then the document should state that they don't know how it came into the sun's orbit and where it came from.
Use the metric system.
Transfer A32tS64—5649-F-001 is unnecessary.
In the Sample description says "bismuth based-based compound". In the same paragraph it says "as previously shown by inspection of images from camera probes". It's a little wordy. Can be written as "as previously theorized from probe's analisis" or "confirming previous probe's analisis". Also, ice of what? It can't be ice water, because the document says that the moss its alive regardles or lack of water, so it can be methane or nitrogen.