arcsecond.io vs NASA

Arcsecond.io is the cloud API behind Arcsecond.local, a multi-user platform observatories run to manage telescopes, night logs, and data packages, but it still exposes the project's original public astronomy-lookup endpoints for object coordinates and exoplanets. Those endpoints are keyless and return live-synced records — /exoplanets/ pulls current rows from the NASA Exoplanet Archive. Paid tiers apply only to running a private observatory instance; the public data-lookup endpoints stay free.

NASA's Open APIs give programmatic access to imagery and data from missions across the agency — the Astronomy Picture of the Day, Mars rover photos, near-Earth object tracking, and Earth-imagery archives among them. A free registered key raises the shared DEMO_KEY's 30-requests/hour limit to 1,000 requests/hour. All endpoints return JSON.