juliensimon/deep-space-probes

Deep Space Probes -- Merged Hourly Data

Credit: NASA/JPL-Caltech

Part of a dataset collection on Hugging Face.

Dataset description

Merged hourly magnetic field, solar wind plasma, and energetic particle measurements from humanity's four most distant spacecraft: Voyager 1, Voyager 2, Pioneer 10, and Pioneer 11.

Each record includes spacecraft position (heliocentric distance, HGI latitude/longitude), interplanetary magnetic field components (RTN coordinates), solar wind plasma parameters (flow speed, proton density, temperature), and energetic particle fluxes at multiple energy channels from the LECP, CRS, and CRT instruments.

Voyager 1 crossed the heliopause (121 AU) in August 2012 and Voyager 2 (119 AU) in November 2018, making this dataset unique in spanning the transition from the heliosphere to interstellar space. Pioneer 10 and 11, launched in 1972-1973, were the first spacecraft to traverse the asteroid belt and encounter Jupiter and Saturn.

The interplanetary magnetic field measurements trace the structure of the Parker spiral carried outward by the solar wind. Solar wind speed, density, and temperature document how the wind decelerates and heats through interactions with pickup ions in the outer heliosphere. The energetic particle fluxes record galactic cosmic rays modulated by the solar cycle, anomalous cosmic rays accelerated at the termination shock, and transient particle events from solar energetic particle events and interplanetary shocks.

This dataset is suitable for tabular regression, time-series forecasting tasks.

Schema

Column	Type	Description	Sample	Null %
spacecraft	str	Spacecraft identifier: voyager_1, voyager_2, pioneer_10, or pioneer_11	pioneer_10	0.0%
datetime	datetime64[us]	Observation timestamp (UTC, hourly cadence) derived from year, day-of-year, and hour in the source data	1972-01-01 00:00:00	0.0%
heliocentric_distance_au	float64	Distance from the Sun in astronomical units (AU); ranges from ~1 AU at launch to 160+ AU for Voyager 1 in interstellar space	0.99	3.8%
hgi_latitude_deg	float64	Heliographic Inertial (HGI) latitude in degrees; measures angular position above/below the solar equatorial plane	-7.2	3.8%
hgi_longitude_deg	float64	Heliographic Inertial (HGI) longitude in degrees; measures angular position in the solar equatorial plane relative to the ascending node of the solar equator on the ecliptic	56.6	3.8%
b_magnitude_nt	float64	Magnetic field magnitude in nT, computed as sqrt(Br^2 + Bt^2 + Bn^2); falls off approximately as 1/r^2 (radial) to 1/r (tangential) with distance	5.1619	59.6%
br_rtn_nt	float64	Radial component of the interplanetary magnetic field in RTN coordinates (nT); positive outward from the Sun along the Parker spiral	0.4189	59.6%
bt_rtn_nt	float64	Tangential component of the magnetic field in RTN coordinates (nT); positive in the direction of planetary motion; dominates at large heliocentric distances	0.0482	59.6%
bn_rtn_nt	float64	Normal component of the magnetic field in RTN coordinates (nT); positive northward; typically small compared to Br and Bt	1.4772	59.6%
flow_speed_kms	float64	Proton bulk flow speed in km/s; typically 300-800 km/s in the inner heliosphere, decelerating in the outer heliosheath; null beyond the heliopause where solar wind is absent	322.6	78.7%
flow_elevation_deg	float64	Flow velocity elevation angle in degrees relative to the RTN radial direction; non-radial flows indicate stream interactions or shock deflections	6.2	79.3%
flow_azimuth_deg	float64	Flow velocity azimuth angle in degrees in the RTN tangential-normal plane; deviations from purely radial flow	-1.7	79.3%
proton_density_cm3	float64	Proton number density in particles/cm^3; decreases roughly as 1/r^2 with heliocentric distance; typical values: ~5 at 1 AU, ~0.001 at 100 AU	5.1725	78.8%
proton_temperature_k	float64	Proton temperature in Kelvin; decreases with distance but more slowly than adiabatic due to pickup ion heating in the outer heliosphere	39856.0	79.1%
b_magnitude_avg_nt	float64	Average magnetic field magnitude in nT, computed as 1/N SUM |B| over the hour; Voyager only, null for Pioneer	5.05	67.9%
flux_h_crs_12p8_17p9_mev	float64	Differential proton flux from CRS instrument in the 12.8-17.9 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0004164	56.2%
flux_h_crs_130p3_154p2_mev	float64	Differential proton flux from CRS instrument in the 130.3-154.2 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0001767	79.6%
flux_h_crs_132p8_154p9_mev	float64	Differential proton flux from CRS instrument in the 132.8-154.9 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002287	76.5%
flux_h_crs_154p2_171p3_mev	float64	Differential proton flux from CRS instrument in the 154.2-171.3 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0001408	79.6%
flux_h_crs_154p9_174p9_mev	float64	Differential proton flux from CRS instrument in the 154.9-174.9 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.00026	76.5%
flux_h_crs_171p3_193p6_mev	float64	Differential proton flux from CRS instrument in the 171.3-193.6 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0001832	79.6%
flux_h_crs_174p9_187p7_mev	float64	Differential proton flux from CRS instrument in the 174.9-187.7 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.000272	76.5%
flux_h_crs_17p9_30p0_mev	float64	Differential proton flux from CRS instrument in the 17.9-30.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.000393	56.2%
flux_h_crs_187p7_220p5_mev	float64	Differential proton flux from CRS instrument in the 187.7-220.5 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002241	76.5%
flux_h_crs_193p6_208p2_mev	float64	Differential proton flux from CRS instrument in the 193.6-208.2 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002077	79.6%
flux_h_crs_208p2_245p7_mev	float64	Differential proton flux from CRS instrument in the 208.2-245.7 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002034	79.6%
flux_h_crs_220p5_270p1_mev	float64	Differential proton flux from CRS instrument in the 220.5-270.1 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.00023	76.5%
flux_h_crs_245p7_272p3_mev	float64	Differential proton flux from CRS instrument in the 245.7-272.3 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002089	79.6%
flux_h_crs_270p1_346p0_mev	float64	Differential proton flux from CRS instrument in the 270.1-346.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002328	76.5%
flux_h_crs_272p3_344p0_mev	float64	Differential proton flux from CRS instrument in the 272.3-344.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.000254	79.6%
flux_h_crs_30p0_48p0_mev	float64	Differential proton flux from CRS instrument in the 30.0-48.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002982	56.2%
flux_h_crs_344p0_478p6_mev	float64	Differential proton flux from CRS instrument in the 344.0-478.6 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.000297	79.6%
flux_h_crs_3p0_4p6_mev	float64	Differential proton flux from CRS instrument in the 3.0-4.6 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.03724	56.2%
flux_h_crs_478p6_598p7_mev	float64	Differential proton flux from CRS instrument in the 478.6-598.7 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002773	79.6%
flux_h_crs_48p0_56p0_mev	float64	Differential proton flux from CRS instrument in the 48.0-56.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002834	56.2%
flux_h_crs_4p6_6p2_mev	float64	Differential proton flux from CRS instrument in the 4.6-6.2 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.005909	56.2%
flux_h_crs_6p2_7p7_mev	float64	Differential proton flux from CRS instrument in the 6.2-7.7 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.002487	56.2%
flux_h_crs_74p5_83p7_mev	float64	Differential proton flux from CRS instrument in the 74.5-83.7 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0002305	76.5%
flux_h_crs_75p9_82p6_mev	float64	Differential proton flux from CRS instrument in the 75.9-82.6 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	3.998e-05	79.6%
flux_h_crs_7p7_12p8_mev	float64	Differential proton flux from CRS instrument in the 7.7-12.8 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0006798	56.2%
flux_h_crt_120p7_227p3_mev	float64	Differential proton flux from CRT instrument in the 120.7-227.3 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	7.57684e-05	71.2%
flux_h_crt_30p55_56p47_mev	float64	Differential proton flux from CRT instrument in the 30.55-56.47 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0	71.2%
flux_h_crt_3p45_5p15_mev	float64	Differential proton flux from CRT instrument in the 3.45-5.15 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	10.51345	71.2%
flux_h_lecp_0p52_1p45_mev	float64	Differential proton flux from LECP instrument in the 0.52-1.45 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	3.531	90.0%
flux_h_lecp_0p57_1p78_mev	float64	Differential proton flux from LECP instrument in the 0.57-1.78 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	1.571	85.3%
flux_h_lecp_22p0_30p0_mev	float64	Differential proton flux from LECP instrument in the 22.0-30.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.0009056	86.8%
flux_h_lecp_22p0_31p0_mev	float64	Differential proton flux from LECP instrument in the 22.0-31.0 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.001205	84.2%
flux_h_lecp_3p04_17p3_mev	float64	Differential proton flux from LECP instrument in the 3.04-17.3 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.004902	87.0%
flux_h_lecp_3p40_17p6_mev	float64	Differential proton flux from LECP instrument in the 3.40-17.6 MeV energy channel, in units of 1/(cm^2 s sr MeV); null when fill values indicate no valid measurement	0.003498	84.2%

Quick stats

• 1,209,696 hourly records (1972-01-01 to 2025-12-31)
• 4 spacecraft: Voyager 1 & 2, Pioneer 10 & 11
• Maximum heliocentric distance: 169.2 AU (Voyager 1)
• Covers heliosphere, heliosheath, and interstellar space
• Voyager 1: 429,528 hourly records
• Voyager 2: 376,944 hourly records
• Pioneer 10: 210,384 hourly records
• Pioneer 11: 192,840 hourly records

Usage

from datasets import load_dataset

ds = load_dataset("juliensimon/deep-space-probes", split="train")
df = ds.to_pandas()

from datasets import load_dataset

ds = load_dataset("juliensimon/deep-space-probes", split="train")
df = ds.to_pandas()

# Voyager 1 in interstellar space (beyond heliopause at ~121 AU)
v1_interstellar = df[
    (df["spacecraft"] == "voyager_1") &
    (df["heliocentric_distance_au"] > 121)
]

# Compare solar wind speed across all probes
for sc in df["spacecraft"].unique():
    sub = df[df["spacecraft"] == sc].dropna(subset=["flow_speed_kms"])
    print(f"{sc}: mean flow speed = {sub['flow_speed_kms'].mean():.0f} km/s")

# Magnetic field decay with distance
import matplotlib.pyplot as plt
v1 = df[df["spacecraft"] == "voyager_1"].dropna(subset=["b_magnitude_nt"])
plt.scatter(v1["heliocentric_distance_au"], v1["b_magnitude_nt"], s=0.1, alpha=0.3)
plt.xlabel("Distance (AU)")
plt.ylabel("|B| (nT)")
plt.yscale("log")
plt.title("Voyager 1: Magnetic Field vs Distance")
plt.show()

Data source

https://spdf.gsfc.nasa.gov/

Update schedule

Monthly (1st at 07:00 UTC). Voyager data is still being collected; Pioneer missions ended in the 1990s.

Related datasets

• juliensimon/solar-wind

• juliensimon/dst-index

• juliensimon/geomagnetic-kp-index

• juliensimon/artemis-ii

• juliensimon/astronauts

• juliensimon/cassini

• juliensimon/chemcam

If you find this dataset useful, please consider giving it a like on Hugging Face. It helps others discover it.

About the author

Created by Julien Simon — AI Operating Partner at Fortino Capital. Part of the Space Datasets collection.

Citation

@dataset{deep_space_probes,
  title = {Deep Space Probes -- Merged Hourly Data},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/deep-space-probes},
  publisher = {Hugging Face}
}

License

CC-BY-4.0