# Archival image sources — Sky Orbit v0.2

Images are retrieved from scientific archives, not generated with AI. The
bundled file inventory, exact asset/source URLs, titles, explanatory notes,
and on-screen credit strings are in `web/data/image-index.json`.

## Digitized Sky Survey

Service: CDS / Université de Strasbourg, HiPS2FITS.

https://alasky.cds.unistra.fr/hips-image-services/hips2fits

Dataset: `CDS/P/DSS2/color` (DSS colored). North up, east left, TAN projection,
ICRS catalog coordinates, 640 × 640 JPEG output. Included objects: M31, M42,
M45, M13, M51, M57. Other fixed catalog objects are fetched only on selection
and cached locally.

Credit: Digitized Sky Survey — STScI/NASA; colored and converted to HiPS by CDS.
HiPS compilation copyright: CNRS/Unistra. The full survey provider's
acknowledgements and copyright references are retained in
`dss-survey-properties.txt`.

## NASA Image and Video Library

API documentation: https://images.nasa.gov/docs/images.nasa.gov_api_docs.pdf

The app includes archived reference images and spacecraft-derived globe
mosaics/reconstructions, with per-object credit. They are not current views of
the selected sky date or phase. The Sun is an ultraviolet false-color image;
Venus is a radar surface reconstruction. Individual NASA archive IDs and
titles remain in the bundled index so each image can be traced to its source.

NASA imagery does not imply endorsement of this application. Original image
credit remains with the listed NASA centers and collaborating institutions.