The Jovian Stratosphere after Comet Shoemaker‐Levy/9: Unusual Isotopic Ratios in Molecular Trace Constituents
Bibliographic record
Abstract
Since the collision of comet Shoemaker-Levy/9 with Jupiter in 1994 July, a number of minor molecular species have been observed to persist in the stratosphere of the planet. Here we report observations acquired in 1998 September at frequencies near 350 GHz (wavelength 850 μm) of HCN and CS and their respective isotopomers H 13 CN, HC 15 N, and C 34 S. Through radiative transfer modeling of the observed lines, we find that the isotopic abundance ratios 12 C/ 13 C, 14 N/ 15 N, and 32 S/ 34 S are considerably elevated with respect to their terrestrial values. We speculate that this result indicates an unusual composition for comet Shoemaker-Levy/9, or that cometary grains evaporated in the collisions significantly modified the isotope ratios.
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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 | 0.000 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".