Wanna take a look around? In 4K? 360*? ON MARS!

[RoGeorge]

[JPortici]

but.. why on youtube?

[Brumby]

To tap into a broader audience.  Not everybody deliberately heads for the NASA website - but YouTube "suggestions" and search results increase potential viewer engagement.

[JPortici]

i remember there being a google-maps-style website

[RoGeorge]

I found this one on https://apod.nasa.gov/apod/astropix.html (not from YouTube recommendation).

YouTube is a very powerful platform to distribute videos all over the world, in general, well, except maybe China and a few other alike countries. No download or install required, also, videos are "grouped" by channels, and channels are easy to subscribe and follow in order to see future similar content, allows comments from viewers, shows viewers rating, and so on.

For this particular image, it is even more advantageous because the "movie" is an interactive view. The user can click and drag the image in order to look around in any direction, upon wish.

Did I misunderstood the question, or are there better alternatives than YouTube?