Licences and credits

1. What is ours

Unless a page says otherwise, the following are © 2026 FALLINGHIPPO LIMITED, which trades as FallingHippo, and its licensors, with all rights reserved except as set out here and in our terms of use:

• the text of the pages, lessons, glossary entries and facts;
• the design of the site, the Heliocodex name and logo;
• the 3D scenes, the sky map and the drawings and diagrams we have made;
• the software that runs the site;
• the way the data has been selected, arranged and put together.

You may share a link to any page, quote short extracts with credit to Heliocodex and a link to the page, show pages to a class, and print or save a page for your own or classroom use. Anything more, such as putting our text, diagrams or software on another site, in a book or in a product, needs our written permission. Email [email protected] and say what you would like to do. We are glad to say yes to schools, teachers, libraries and non-profit projects, and we usually do.

2. Photographs and images

The photographs on the planet pages are from NASA missions and photographers. Each has its credit under it, and every one is listed with its mission on the sources page.

How NASA material may be used. NASA’s media guidelines say NASA content is generally not subject to copyright in the United States, and that it may be used for educational or informational purposes, including web pages, as long as NASA is acknowledged as the source. They say it must not be used to suggest that NASA endorses a product, service or organisation, and that NASA’s insignia, logotype and seal are not in the public domain and need NASA’s approval. JPL’s policy asks for a credit such as “Courtesy NASA/JPL-Caltech” unless the caption says otherwise. We follow both: each image carries the credit that came with it, no NASA or JPL logo is used anywhere on the site, and the terms and the foot of every page say that Heliocodex is independent of NASA.

What we have done to them. We have resized and compressed the images so that they load quickly. We say in the caption where an image has been computed, coloured or enhanced by someone else, for example the Great Red Spot picture, which is an enhanced colour image made by Gerald Eichstädt from JunoCam data, and the picture of Maat Mons, which is computer-generated from Magellan radar data with the height exaggerated.

Images that have an owner besides NASA. Where NASA has used a third party’s picture, or a person has processed NASA’s data and credited themselves, that person keeps their rights and their credit, and NASA’s permission does not pass on theirs. If you want to reuse a photograph from this site, please go to NASA or the source in the credit, check the terms that come with the original and use their copy, not ours.

People in pictures. Where people appear in an image, such as the launch photograph, the rights in their likeness aren’t covered by the NASA guidelines. Don’t use those images commercially without checking.

Videos. A few lessons carry a video made by NASA, mostly by its Goddard Space Flight Center and Scientific Visualization Studio, and hosted on NASA’s own YouTube channels. Like NASA’s photographs, NASA video is generally not subject to copyright in the United States, and its media guidelines apply: NASA is credited beside each video, and nothing here suggests that NASA endorses Heliocodex. The still picture shown before you press play is a frame from the same video. A video plays from YouTube only when you press its Play button; see cookies and storage for what that does.

3. Maps and textures

The maps wrapped round each world in the 3D view are from Solar System Scope, under the Creative Commons Attribution 4.0 International licence (CC BY 4.0). Solar System Scope builds them from NASA mission imagery. We changed them: we resized them, converted them to smaller formats and, for Mercury and the Earth’s clouds, turned them to greyscale. Under the licence you may share and adapt them, including commercially, if you credit Solar System Scope, link to the licence and say what has been changed. If you take them from us, please do the same, and better still get them from the source.

The Earth-by-night map is built from NASA’s Black Marble, and the Earth-by-day map from NASA’s Blue Marble, as the sources page explains.

4. Star, galaxy and sky data

Facts, figures and measurements aren’t covered by copyright in themselves, but the collections they come from can be, and many authors ask to be cited. We cite every source we use on the page that uses it, and a full list is on the sources page.

5. Data files you may use

The star files that we publish under /data, including the file of star positions, brightness and colours and the file of star details, are made from the HYG database and are shared under CC BY-SA 4.0. That means you may copy, share and adapt them, including commercially, if:

• you credit both Heliocodex and the HYG database (David Nash) and link to the licence;
• you say if you have changed them;
• you share anything you build from them on the same licence.

The licence covers the data. It doesn’t cover the rest of the site, which stays under section 1. The other files in the data folder are made from the catalogues in the table above and are shared on the terms of those catalogues. If in doubt, ask us.

6. Fonts

Each page has its own typeface. They are free under the SIL Open Font Licence 1.1 and are served from this site, not from Google or anyone else, through the Fontsource packages: Spectral, IBM Plex, Fraunces, Archivo, Bodoni Moda, Source Serif, Libre Caslon, Newsreader, Young Serif, Literata, Bevan, Libre Franklin, Italiana, EB Garamond, Instrument Serif, Big Shoulders and Inter. Each font’s designers and its copyright notice are on the Fontsource page for it.

7. Software

The site is built with open-source software, used under its licences:

The MIT licence requires us to keep the copyright notices of its authors with their code. They are in the packages and on the projects’ own pages. The software that is ours, the code that makes Heliocodex itself, is covered by section 1.

8. Names and trade marks

NASA, JPL, ESA, the names of missions and spacecraft, Solar System Scope, Fontsource and other names on the site belong to their owners, and we use them only to say where something comes from. A mention is not an endorsement either way. Heliocodex is independent. It isn’t run, approved or sponsored by any of them, and nothing here suggests they have endorsed this site.

9. How to ask us, or to tell us about a problem

To ask for permission to reuse our work, email [email protected]. Tell us what you want to use, where and why.

To tell us we have used something we shouldn’t, or got a credit wrong, email [email protected] with “Credit or copyright” in the subject. Please tell us:

• who you are and, if you are writing for the owner, how you are connected to them;
• which page and which picture, text or data you mean, with the address;
• what the problem is, and what you would like us to do, such as change a credit or take something down;
• how we can reach you.

We look at every message promptly, normally within 5 working days. Where something is wrongly credited we correct it, and where we’ve no right to use something we remove it while we sort it out. This page is for matters about material that is on the site. We don’t host files or comments from other people.

10. Changes

We update this page when we add a new source, picture or tool, and change the date at the top.

• 11 November 2026. First version, written for the launch of the new Heliocodex.