NASA

Overview

NASA’s open API portal exposes a set of public data services: the Astronomy Picture of the Day (APOD), Near-Earth Object web service (NeoWs), Mars Rover photos, Earth Polychromatic Imaging Camera (EPIC) imagery, and the NASA Image and Video Library. A free API key is recommended, and a DEMO_KEY lets you try endpoints immediately without registration.

Quick Start

Astronomy Picture of the Day (works right away with DEMO_KEY):

curl "https://api.nasa.gov/planetary/apod?api_key=DEMO_KEY"

Near-Earth asteroids for today:

curl "https://api.nasa.gov/neo/rest/v1/feed/today?api_key=DEMO_KEY"

Mars Rover photos (Curiosity, sol 1000):

curl "https://api.nasa.gov/mars-photos/api/v1/rovers/curiosity/photos?sol=1000&api_key=DEMO_KEY"

Authentication

• Register at api.nasa.gov for a free personal API key (instant).
• No key at all? Use DEMO_KEY — it works, but the limit is shared across all demo users.
• Send the key as the api_key query parameter.

Rate Limits & Notes

• Default rate limit: 30 requests per hour per IP with a personal key (the demo key shares the same pool).
• Response caching is recommended — APOD images and NEO data don’t change every minute.
• Some endpoints (APOD, NEO) are CORS-friendly; when in doubt, call from a server.
• Mars rover photos and EPIC are great for visual projects but can be large — consider thumbnails.

FAQ

Is the NASA API free? Yes — registration is free and comes with a personal key (30 req/hr default).

Do I need an API key? A key is recommended; DEMO_KEY works for trying things out without signing up.

What can I build with it? Daily astronomy images (APOD), asteroid trackers (NeoWs), Mars photo galleries — popular for wallpapers, widgets, and space-themed apps.