Table 1.
Summary of spacecraft observations
| Mission | Date | Sys III. Longitude (°) | Filters (nm)2 | Related Features3 | Visibility Notes |
|---|---|---|---|---|---|
| Voyager 1 | 1979–01-08 to 1979–03-05 | --- | --- | A, C, S | --- |
| Voyager 2 | 1979–06-26 to 1979–07-08 | 30–90 | 325, 400, 585, 615, 619 | FC. Some S to East, A & C elsewhere | ≥ 297 hours. |
| HST | 1995–02-17 1995–10-05 1996–10-21 2007–02-26 2007–03-26 2008–05-10 | --- | --- | A, C, S | --- |
| HST | 2012–09-20 | 295–300, 20-45, 130–160, 200–260 | 275 | A, C, FC?, S | Faint, ≥ 20 hrs. None at 763 nm. |
| HST | 2015–01-19 | 180–360 | 275, 343, 395, 502, 547, 631, 658, 889 | A, C, FC, S | ≥ 20 hrs |
| HST | 2016–02-09 | 50–55 | 343, 395, 467, 502, 547, 631, 658 | C. Elsewhere A, S. | ≥10 hrs. None at 275, 889. |
| HST | 2016–12-11 | 70–100 | 343, 395, 502, 631, 727, 750 | C. Elsewhere A, S. | Faint, ~10 hr. None in 225, 275, 889 |
| HST | 2017–01-11 | 85–135, 225–260 | 225, 275, 343, 395, 502, 631, 727, 750, 889 | C. Nearby | Faint at 225 and 889 |
| HST | 2017–02-01 | 25–75, 160–210 | 225, 275, 343, 395, 502, 631, 727, 750, 889 | C. Nearby A, S elsewhere. | ≥ 10 hrs. |
| HST | 2017–04-03 | 5–55, 235–305 | 275, 343, 395, 502, 547, 631, 658, 889 | A, C, FC. Some S to East | ≥10 to 20 hrs, but fading. |
| HST1 | 2017–05-19 | 135–150, 190–215 | 343, 395, 502, 631, 727 | S, A and FC at ends. | Faint in 135–150 portion. None in 275, 889, faint in 727. |
| HST1 | 2017–07-11 | 315–20 | 275, 343, 395, 502, 631, 727, 750 | A, C, FC. Weak S nearby? | Faint in 275. None at 889. |
| HST1 | 2018–02-06 | 175–230 | 275 | S, FC?, nearby A | Faint in 275. None in 225, 343, 395, 502, 631, 727, 750, 889 |
| HST | 2018–04-01 | 180–230, 285–300 | 343, 395, 502 | C, A | Faint in 275, 631. None in 225, 889. |
| HST | 2018–04-17 | 35–180, 200–270 | 275, 343, 395, 502, 467, 631, 658, 889 | C, A, S | Faint at 225 and 889 |
Notes:
1.
All observations included global coverage, except May and June 2017 and February 2018.
2.
Filter wavelengths given here correspond to the names of WFC3/UVIS filters, as given in Table 6.2 of Dressel (2017).
3.
Related features are those that are prominent over longitudes covered by the waves, or, on dates without waves, present at any longitude. A: Anticyclones, C: cyclones, FC: forming cyclones (less-defined shape), S: NEB storms.