Ground-to-space observations of the 20 May 2023 bolide over Australia
Bibliographic record
Abstract
Very bright meteors, also referred to as fireballs and bolides, are generally produced by objects >10 cm in diameter. While impacts by large asteroids (10s of meters in diameter) are relatively rare, they are not statistically negligible. Such objects carry a destructive potential, as illustrated by the Chelyabinsk event that occurred over a decade ago. Thus, the characterization of these objects is of utmost importance, and helps shed light on why some events might result in more catastrophic outcomes than others. Different sensing modalities can be used in unison to derive various bolide parameters, including its trajectory, entry velocity, and energy deposition, among others. In addition to producing a spectacular display in the sky, bolides are also capable of generating shockwaves. A by-product of shockwaves is a low frequency (< 20 Hz) acoustic wave, or infrasound. Acoustic sensing using infrasound stations installed around the globe has gained momentum over the last decade due to its capability to detect bolides and help estimate their energy deposition irrespective of time of day or cloud coverage. Infrasound is generally used in conjunction with other sensing modalities, such as optical observations, which provide important ground truth information. We present the ground-to-space observations of an energetic bolide that resulted in an airburst over Australia on 20 May 2023. The bolide entered with a speed of 28 km/s over Queensland at 09:22 pm local time, and underwent a catastrophic disintegration at an altitude of 29 km. It deposited energy of ~7.2 kt of TNT equivalent (1 kt = 4.184·1012 J), making it one of the top 20 most energetic bolides detected by the US government sensors and reported in the JPL/NASA CNEOS database since 1988. The bolide was so bright that it was visible at a distance of 600 km. It saturated ground-based cameras, stifling efforts to derive the full trajectory and obtain photometric measurements. We found infrasound signals at four infrasound stations as far as 6000 km away. The energy estimate derived through infrasound signal analysis is ~7 kt of TNT equivalent, which corroborates the value reported by the CNEOS database. We will present observations of this energetic bolide event and discuss implications for planetary defense and characterization of similar events.SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".