juliensimon/esa-exomars-tgo-observations

ESA ExoMars TGO Observations

Credit: NASA/JPL-Caltech

Part of a dataset collection on Hugging Face.

Dataset description

Complete observation metadata catalog from the ESA ExoMars Trace Gas Orbiter (TGO) mission -- studying Mars atmosphere, surface, and subsurface since the spacecraft entered orbit in October 2016.

TGO's primary scientific goal is to study the Martian atmosphere with unprecedented sensitivity, searching for trace gases such as methane that could indicate active geological or biological processes. The mission also maps subsurface hydrogen (a proxy for water ice) and captures high-resolution color and stereo surface images.

TGO carries four science instruments: ACS (Atmospheric Chemistry Suite, three infrared spectrometers achieving parts-per-trillion sensitivity), CaSSIS (Colour and Stereo Surface Imaging System, ~4.5 m/pixel), FREND (Fine Resolution Epithermal Neutron Detector, maps subsurface hydrogen), and NOMAD (Nadir and Occultation for Mars Discovery, UV/visible/IR spectrometer suite).

TGO's atmospheric measurements have placed the most stringent upper limits on methane in the Martian atmosphere. ACS and NOMAD observations have revealed new details about atmospheric dust, water vapor vertical profiles, and the mechanisms driving water escape from Mars. FREND has produced refined maps of near-surface water-equivalent hydrogen. CaSSIS images active surface processes including recurring slope lineae, dust devil tracks, and fresh impact craters.

Each row represents one observation or data granule from the ESA Planetary Science Archive (PSA), conforming to the EPN-TAP standard, with timing, spatial coverage, instrument parameters, and access URLs.

Instruments

• CaSSIS: 18,317,986 observations
• ACS: 8,273,770 observations
• NOMAD: 445,300 observations
• FREND: 38,919 observations
• DREAMS: 77 observations

Quick stats

• 27,076,052 total observations
• 5 instruments
• 1 distinct targets
• Time span: JD 2457461.5 -- 0.0

Usage

from datasets import load_dataset

# Load a single instrument (fast, low memory)
acs = load_dataset("juliensimon/esa-exomars-tgo-observations", "acs", split="train")
print(f"{len(acs):,} ACS observations")

# Load all instruments at once (27M+ rows, needs ~8 GB RAM)
ds = load_dataset("juliensimon/esa-exomars-tgo-observations", split="train")

# Available configs: cassis, acs, nomad, frend, dreams

# Plot observation timeline
import matplotlib.pyplot as plt

df = acs.to_pandas()
df["time_min"].hist(bins=100, figsize=(12, 4))
plt.title("ACS Observation Timeline")
plt.xlabel("Julian Date")
plt.ylabel("Observations")
plt.tight_layout()
plt.show()

Data source

ESA Planetary Science Archive -- EPN-TAP service at https://psa.esa.int/psa-tap/tap/sync.

Update schedule

Weekly (Monday at 09:00 UTC)

Related datasets

• juliensimon/nasa-maven-kp-insitu
• juliensimon/esa-mars-express-observations
• juliensimon/nasa-mars-rover-images
• juliensimon/esa-bepicolombo-observations

Citation

@dataset{esa_exomars_tgo_observations,
  title = {ESA ExoMars TGO Observations},
  author = {juliensimon},
  year = {2026},
  url = {https://huggingface.co/datasets/juliensimon/esa-exomars-tgo-observations},
  publisher = {Hugging Face}
}

License

CC-BY-4.0