Jupiter Radio Burst Forecast API

The Jupiter Radio Burst Forecast API predicts when Jupiter will emit decametric (DAM) radio bursts at 20.1 MHz. Burst probability is computed from the orbital geometry of Io and Jupiter’s Central Meridian Longitude (CML) using pg_orrery ephemeris functions. Only time steps where Jupiter is above the local horizon are included in the forecast.

Tip

Jupiter produces some of the strongest natural radio emissions in the solar system. These decametric bursts at 20.1 MHz are driven by the interaction between Io’s plasma torus and Jupiter’s magnetosphere. Ham radio operators can receive them with a simple dipole antenna and a receiver tuned to 20.1 MHz — no dish required.

Burst Forecast

Returns a time series of burst probability values over a configurable forecast window.

GET /api/jupiter/bursts

Query Parameters

Parameter	Type	Default	Description
hours	int	24	Forecast window length (1-168 hours)
step	int	10	Time step between entries in minutes (1-60)

Note

Only entries where Jupiter is above the observer’s horizon (jupiter_elevation > 0) are returned. If Jupiter does not rise during the forecast window, the response will contain zero entries and jupiter_visible will be false.

Response

{
  "entries": [
    {
      "time": "2026-02-20T20:30:00+00",
      "io_phase_deg": 225.4,
      "cml_deg": 95.9,
      "probability": 0.0,
      "jupiter_elevation": 9.8
    },
    {
      "time": "2026-02-20T20:40:00+00",
      "io_phase_deg": 225.8,
      "cml_deg": 101.8,
      "probability": 0.15,
      "jupiter_elevation": 12.3
    }
  ],
  "count": 36,
  "peak_probability": 0.72,
  "peak_time": "2026-02-21T03:15:00+00",
  "jupiter_visible": true
}

Response Fields

Field	Type	Description
time	string	ISO 8601 timestamp for this forecast step
io_phase_deg	float	Io’s orbital phase angle (0-360 degrees)
cml_deg	float	Jupiter’s Central Meridian Longitude (0-360 degrees)
probability	float	Burst probability for this time step (0.0-1.0)
jupiter_elevation	float	Jupiter’s elevation above the horizon in degrees
count	int	Total number of entries returned
peak_probability	float	Highest burst probability in the forecast window
peak_time	string or null	ISO 8601 time of peak probability, or null if no bursts predicted
jupiter_visible	bool	Whether Jupiter rises above the horizon at any point during the window

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Burst Probability Zones

Burst probability depends on the combination of two angles: Io’s orbital phase and Jupiter’s CML. The known active source regions are:

Source	CML Range	Io Phase Range	Notes
Io-A	~200-260 degrees	~195-265 degrees	Most commonly observed source
Io-B	~90-200 degrees	~80-130 degrees	Strongest bursts, broad CML window
Io-C	~290-10 degrees	~220-260 degrees	Weaker, best at high CML values

Tip

When peak_probability is above 0.5 and jupiter_elevation is at least 10 degrees, conditions are favorable for listening. Point a half-wave dipole cut for 20.1 MHz toward Jupiter’s azimuth and tune your receiver to 20.1 MHz with a wide bandwidth (at least 10 kHz). Bursts sound like ocean waves crashing — a characteristic swooshing pattern lasting seconds to minutes.

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Error Handling

If the pg_orrery Jupiter functions (io_phase_angle(), jupiter_cml(), jupiter_burst_probability()) are unavailable, the endpoint degrades gracefully:

{
  "entries": [],
  "count": 0,
  "peak_probability": 0.0,
  "peak_time": null,
  "jupiter_visible": false
}

Examples

Forecast the next 48 hours with 15-minute resolution:

GET /api/jupiter/bursts?hours=48&step=15

Quick check for tonight’s conditions (default 24 hours, 10-minute steps):

GET /api/jupiter/bursts