juliensimon/esa-huygens-titan-descent

---
license: cc-by-4.0
pretty_name: "ESA Huygens Titan Descent"
language:
- en
description: "In-situ observation catalog from the ESA Huygens probe descent through Titan's atmosphere and landing (13,995 observations across 8 instruments). Static dataset from the ESA Planetary Science Archive."
task_categories:
- tabular-classification
tags:
- space
- titan
- huygens
- cassini
- saturn
- esa
- planetary-science
- atmosphere
- open-data
- tabular-data
- parquet
size_categories:
- 10K<n<100K
configs:
- config_name: default
data_files:
- split: train
path: data/huygens_observations.parquet
default: true
---

# ESA Huygens Titan Descent

<div align="center">
<img src="banner.jpg" alt="Saturn and its rings, captured by the Cassini spacecraft" width="400">
<p><em>Credit: NASA/JPL-Caltech/SSI</em></p>
</div>

*Part of the [Solar System Datasets](https://huggingface.co/collections/juliensimon/solar-system-datasets-67d1e3b4343a25fc6cf402b4) and [Planetary Science Datasets](https://huggingface.co/collections/juliensimon/planetary-science-datasets-69c24cb17e3db14fc30f0716) collections on Hugging Face.*

On January 14, 2005, the ESA Huygens probe made history as the first human-made object to land on a body in the outer Solar System. Released from the Cassini orbiter, Huygens descended through Titan's thick nitrogen-methane atmosphere for 2 hours 27 minutes, transmitting data from 160 km altitude down to the surface. The Descent Imager/Spectral Radiometer (DISR) captured images revealing drainage channels, shorelines, and a landscape shaped by liquid methane — evidence of an active hydrological cycle on another world. The Gas Chromatograph Mass Spectrometer (GCMS) analyzed atmospheric composition during descent, while the Huygens Atmospheric Structure Instrument (HASI) measured temperature, pressure, and density profiles. The Surface Science Package (SSP) recorded the impact and confirmed Huygens landed on a soft, damp surface — likely methane-saturated hydrocarbon sediment. This dataset is the only in-situ observation catalog from Titan's surface and atmosphere.

## Dataset description

This dataset contains **13,995** observations across 8 instruments from the ESA Planetary Science Archive (PSA), conforming to the EPN-TAP standard. Each row represents one observation or data granule, with timing, spatial coverage, instrument parameters, and access URLs.

## Instruments

- **DISR**: 12,024 observations
- **GCMS**: 1,606 observations
- **HUYGENS_HK**: 217 observations
- **HASI**: 118 observations
- **SSP**: 16 observations
- **DTWG**: 7 observations
- **ACP**: 4 observations
- **DWE**: 3 observations

## Schema (key columns)

| Column | Type | Description |
|--------|------|-------------|
| `granule_uid` | string | Unique observation identifier |
| `granule_gid` | string | Group identifier |
| `obs_id` | string | Observation ID |
| `dataproduct_type` | string | Data product type (e.g. spectrum, image, profile) |
| `target_name` | string | Target body (Titan) |
| `target_class` | string | Target class (satellite) |
| `instrument_name` | string | Instrument name (DISR, GCMS, HASI, SSP, etc.) |
| `time_min` | float64 | Observation start time (JD) |
| `time_max` | float64 | Observation end time (JD) |
| `c1min`/`c1max` | float64 | Spatial coordinate 1 range |
| `c2min`/`c2max` | float64 | Spatial coordinate 2 range |
| `spectral_range_min`/`max` | float64 | Spectral range bounds |
| `processing_level` | string | Data processing level |
| `creation_date` | string | Data product creation date |
| `access_url` | string | URL to access the data product |
| `access_format` | string | Data format (e.g. application/x-pds) |

The full schema contains up to ~50 columns following the EPN-TAP standard.

## Quick stats

- **13,995** total observations
- **8** instruments
- **1** distinct targets
- Time span: JD 2450574.5 – 2453385.3

## Usage

```python
from datasets import load_dataset

ds = load_dataset("juliensimon/esa-huygens-titan-descent", split="train")
df = ds.to_pandas()

# Observations per instrument
print(df["instrument_name"].value_counts())

# DISR imaging observations
disr = df[df["instrument_name"] == "DISR"]
print(f"{len(disr):,} DISR observations")

# Filter by descent phase (time range)
import matplotlib.pyplot as plt
df.groupby("instrument_name").size().sort_values(ascending=False).plot(kind="bar")
plt.title("Huygens observations by instrument")
plt.ylabel("Count")
```

## Data source

[ESA Planetary Science Archive](https://psa.esa.int/) — EPN-TAP service at
`https://psa.esa.int/psa-tap/tap/sync`.

## Related datasets

- [esa-rosetta-observations](https://huggingface.co/datasets/juliensimon/esa-rosetta-observations) — ESA Rosetta comet mission
- [cassini](https://huggingface.co/datasets/juliensimon/cassini) — Cassini Saturn orbiter
- [galileo-atmosphere](https://huggingface.co/datasets/juliensimon/galileo-atmosphere) — Galileo Jupiter atmospheric probe
- [huygens-atmosphere](https://huggingface.co/datasets/juliensimon/huygens-atmosphere) — Huygens atmospheric profiles

## Pipeline

Source code: [juliensimon/space-datasets](https://github.com/juliensimon/space-datasets)

## Support

If you find this dataset useful, please give it a ❤️ on the [dataset page](https://huggingface.co/datasets/juliensimon/esa-huygens-titan-descent) and share feedback in the Community tab! Also consider giving a ⭐️ to the [space-datasets](https://github.com/juliensimon/space-datasets) repo.

## Citation

```bibtex
@dataset{huygens_titan_descent,
author = {Simon, Julien},
title = {ESA Huygens Titan Descent},
year = {2026},
publisher = {Hugging Face},
url = {https://huggingface.co/datasets/juliensimon/esa-huygens-titan-descent},
note = {Based on ESA Planetary Science Archive (PSA) EPN-TAP service}
}
```

## License

[CC-BY-4.0](https://creativecommons.org/licenses/by/4.0/)