Youtube does not permit a direct download on a web browser; however, a downloadable software exists through external sources.
Here we provide the best option for MacOS, Microsoft Windows, and Ubuntu users.
https://www.4kdownload.com/products/pro ... downloader
1. Download the software
2. Copy the link of your video
3. Click “paste link” in the application
As an alternative option, some web-browsers offer free extensions which you can set-up to download videos:
Firefox and Google Chrome: https://addoncrop.com/youtube_video_downloader/
1. Download the extension for your specific browser
2. While playing the Youtube video, click the download button that the extension adds under the video
3. Select video format and the video will be added to your system
NASA disclaimer on external links: https://descanso.jpl.nasa.gov/privacy.html