Summary

2024 UQ is the tenth imminent impactor observed in space before hitting the Earth. It was first observed by ATLAS, but reported after the impact had already happened. It was subsequently confirmed with pre-discovery detections. 

Discovery circumstances and follow-up

The asteroid was discovered by the ATLAS survey station on Haleakala, Hawaii, USA. The survey reported 6 positions only 10 hours after they were observed; when processed by the imminent impact detection systems, an almost certain impact less than 2 hours after discovery was detected. Despite no directed follow-up being possible, additional searches for pre-discovery images led to the identification of a faint detection in a set of images taken by the Catalina Schmidt telescope just an hour before ATLAS observed it. The combination of the two datasets allows for a much better determination of the orbit, and confirm an impact point in the Northeast Pacific Ocean. 

Trajectory in Space

In the video below, the autumn equinox points to the bottom left corner of the image. The view is tilted by approximately 30 degrees above the Ecliptic.

Trajectory Relative to the Earth

The video below shows the trajectory in space of 2024 UQ in the hours prior to its impact with Earth. The size of the asteroid is greatly magnified in order to make it visible.

2D Impact Corridor

The plot below shows the entry point on the ground, without including the atmospheric effects.

3D Impact Corridor

The highlighted area in the animation below represents the 1-σ (in red) and the 3-σ (in orange) fall area of the propagated object without including the atmospheric effects.

Atmospheric phase details 

The fireball occurred over the Pacific Ocean several kilometres off-coast and therefore no on-ground record is expected. However, it has been detected from space by a GOES satellite (GLM instrument) and by U.S. government satellite sensors. The meteoroid entered the atmosphere at 21 km/s, making it the fastest impactor so far, together with 2024 RW1. According to CNEOS, the disintegration took place at an altitude of 38 km of altitude, releasing 0.15 kt of energy.

Search for meteorites

No meteorites could be recovered due to the location of the impact point over oceanic waters.