A comparison of magnetic overshoots at the bow shocks of Mercury and Saturn
Bibliographic record
Abstract
The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft at Mercury and the Cassini spacecraft at Saturn provide us with orbiters around planets at more diverse heliocentric distances than ever before. The dramatically different solar wind conditions at these two planets should mean that Mercury's bow shock is considerably weaker (lower Mach numbers) than Saturn's bow shock. This is expected to produce different magnetic overshoot amplitudes at each bow shock, because the Relative Overshoot Amplitude (ROA) has been shown to increase with both fast magnetosonic Mach number and upstream plasma β . We qualitatively compare the parameter regimes of Mercury's and Saturn's bow shock by determining ROAs. We analyze 133 MESSENGER encounters with Mercury's bow shock and 90 Cassini encounters with Saturn's bow shock, all with a clear shock ramp. At five of the 133 Mercury bow shock encounters, there is no resolvable magnetic overshoot, whereas all Saturn bow shock encounters have a clear overshoot. We find that the ROA of Mercury's bow shock ranges from ~0 (no overshoot) to ~0.6, with a typical value of ~0.2. We find that the ROA of Saturn's bow shock ranges from ~0.2 to ~5, with a typical value of ~2. This clear ROA difference is consistent with the expected lower fast magnetosonic Mach number and lower upstream plasma β at Mercury's bow shock, and we suggest that it is very likely to be primarily caused by the different Mach numbers. This confirmed variation in bow shock parameter regime may produce a different solar wind‐magnetosphere interaction at these two planets.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".