Ulysses GAS: Interstellar Helium Sky Maps from the Ulysses Spacecraft

Ulysses GAS experiment data provides pixel map data and image files for sky maps generated from measurements of neutral helium atoms flowing into the heliosphere. The dataset includes accumulated counts and Ecliptic angle coordinates in ASCII files, with full images provided in GIF and PostScript formats. It was produced by the National Aeronautics and Space Administration, with key methods described in publications from 1992 and 1996.

Use Cases

• Modeling the inflow direction and density of interstellar helium based on the accumulated count data.
• Visualizing the distribution of neutral helium in the sky relative to celestial bodies using the provided GIF and PostScript image files.
• Analyzing temporal variations in the interstellar gas flow by comparing maps from different points along the Ulysses spacecraft trajectory.
• Studying the exclusion zone around the Sun to understand instrument safety constraints and data gaps.

Strengths

• Includes multiple data representations: ASCII tables with coordinates and counts, plus GIF and PostScript image files.
• Provides a user guide (USER_GUIDE.TXT), format specification (FORMAT.TXT), and reference list (REFERENCE.TXT) for documentation.
• Positions of the Sun, Earth, and Jupiter are indicated within the image files for spatial context.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The area around the Sun is excluded from observation, creating a data gap.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Measurements from the GAS (Gaseous) experiment on the Ulysses spacecraft.

Time Range

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Freshness

Last updated 2026-03-13 09:21:53.734514; freshness should be verified.

Geography

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