Cape Cod Meteor Traced Back to an Orbit Near Jupiter

Size, energy and composition

Scientists estimate the object was about one metre across before entering the atmosphere. Its breakup released energy equivalent to 1.1 kilotons of TNT, or roughly 1,100 tons. Measurements suggest it was very hard and possibly rich in iron, which would explain why fragments survived and fell into the waters of the bay.

The team was led by space physicist Juha Vierinen of the Arctic University of Norway. It combined data from meteor-detection radars, weather radars, low-frequency acoustic stations and dashcam and security recordings. MIT's SIMONe network was a key source, picking up radar signals from the ionised air around the meteor. Four weather radar stations tracked the cloud of fragments, while acoustic data helped estimate the energy released.

An orbit shaped by Jupiter

The calculations show an elongated elliptical orbit around the Sun stretching out toward Jupiter, similar to those of Jupiter-family comets. The researchers stressed that the object was not a comet. It is more likely a piece of a small asteroid from the main belt between Mars and Jupiter. The meteor was not linked to any known meteor shower.

Jupiter's gravity may have nudged it onto a new path that crosses Earth's orbit. Researcher Mark Fries said the aphelion, the farthest point from the Sun, lies near Jupiter's orbit, supporting that scenario.

Objects only a few metres across are hard to spot before they enter the atmosphere and fall too rarely for easy study. Rebuilding their orbits helps explain where meteorites and near-Earth asteroids come from and could improve estimates of potentially hazardous bodies. The study also shows that combining radar, acoustic and optical data can characterise such objects even when they fall in daylight.