The astronauts on board the International Space Station have access to a range of sophisticated equipment, including a RED Epic Dragon camera that is capable of shooting video at resolutions to 6K (that is, 6144 x 3160 pixels). Naturally, one of first things the astronauts did was to grow a water bubble, fill it with dye and then dissolve an effervescent tablet in that floating ball of water. The results are superb, check it out below. If you have a monitor capable of displaying 4K, be sure to select the 2160p quality setting for the full effect.
To see more 4K videos from NASA, check out their Ultra High Definition playlist on YouTube.