Specific allegation
Earth sometimes captures small asteroids temporarily, prompting claims of a concealed second Moon. Temporary mini-moons are real but faint and short-lived, not stable Moon-sized companions. Objects such as 2024 PT5 were tracked as small natural bodies with changing orbits and public observations.
Chronology and context
Dynamical models predicted temporary captures; surveys later detected a few. Their brief residence makes discovery difficult, and short observation arcs can leave uncertain classifications. A temporary capture may later be described as a close approach rather than a bound satellite. No large second moon has appeared in tracking records.
Observations and physical record
Repeated astrometry gives motion and orbit; independent telescopes can confirm a candidate. Large stable moons would be brighter and gravitationally perturb Earth-Moon trajectories. Catalogs document known mini-moons and close approaches, but small faint objects may remain undetected until observed.
Established scientific account
A mini-moon is a small asteroid temporarily captured in Earth’s gravitational neighborhood. Its orbit and duration can be calculated. This differs from a Moon-sized satellite that has remained hidden for years; such an object would be conspicuous in optical and dynamical records.
Limits and contrary evidence
Small asteroids evade surveys, especially when faint or near the Sun, and initial orbit solutions can change. That observational incompleteness is ordinary, not evidence of concealment. Temporary captures are publicly announced after confirmation and do not support a secret artificial satellite.
What could change the assessment
Require a designation, multi-night astrometry, a reproducible orbit, and independent confirmation. NASA/JPL ephemerides can test trajectory. A cover-up claim needs evidence that a verified stable object was deliberately withheld, not merely a delayed discovery or revised orbit.
Short observation arcs can make a temporary capture’s exact status uncertain, and classification depends on the chosen dynamical definition. That is a real catalog issue rather than concealment. A second Moon-sized satellite would be a wholly different case: its brightness and long-term gravitational effects would be obvious in precision tracking.
Calibrated conclusion
Small temporary mini-moons are real, but no large hidden second Moon is known. The phenomenon is public and distinct from a secret stable satellite.
Sources and scope
- NASA CNEOS close approachesOrbit and close-approach records for near-Earth objects.
- Granvik et al., Nature: natural Earth satellitesModeling predicts temporary captures and observational difficulty.
- NASA/JPL HorizonsIndependent orbital calculations when object data exist.