Czech astronomer Zdeněk Mikulášek at Czech Astronomical Society congress 2017.
This file is available under <a rel="nofollow" class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/">Creative Commons BY-SA license</a>. Basically: You can use this picture for any purpose, provided that you attribute it to <i>Pavel Hrdlička, Wikipedia</i>. You may distribute the resulting work under the same license.
<span class="int-own-work" lang="en">Own work</span>