These objects are tracked and are NOT on a collision course with Earth. “If it hits” is a hypothetical to show scale.
Near-Earth object · discovered 2024-12-27
2024 YR4
Discovered days after a prior close pass — the 'we didn't see it coming' object. Its impact odds briefly rose to the highest recorded since 2004, then were ruled out within three weeks.
43
watch score
How bigiEstimated from brightness and an assumed albedo. Radar or a spacecraft visit would tighten it.
60m
range 40–90 m
How closeiLD = lunar distance (~384,400 km). The closest the object's path brings it to Earth's centre.
2.1LD
range ≈828,000 km
How fastiVelocity relative to Earth at closest approach.
19km/s
range 17–21 km/s
CompositioniInferred from spectral type. Drives whether an impact would airburst or reach the ground.
Stony
range Stony (assumed)
If it hit — a scale comparison, not a forecast
How big is that, really?
Bus12 m
This object60 m
20-storey tower65 m
Stadium250 m
Eiffel Tower330 m
Impact energyiKinetic energy converted to TNT-equivalent, with the size and speed ranges propagated through.
15 Mt
range 3.5 Mt – 60 Mt
Where that sits
Hiroshima
Chelyabinsk
Tunguska
Tsar Bomba
At this size and speed it would most likely airburst high in the atmosphere — energy between Tunguska 1908 (~12 Mt) and Tsar Bomba (~50 Mt), shown as a bracket, not a single number.