Update videos on the landing page

data/public.md

@@ -21,13 +21,15 @@ planets, galaxies, or even the whole universe. We do this to test theories
 about what the universe is made of and how it evolved from the Big Bang up to
 the present day!
 
-<div class="videowrapper"><iframe width="100%" height="100%" src="https://www.youtube.com/embed/UJYV6f8SwdQ" frameborder="0" allowfullscreen></iframe>
+<div class="videowrapper"><iframe width="100%" height="100%" src="https://www.youtube.com/embed/DF2FV4HiVBU" frameborder="0" allowfullscreen></iframe>
 </div>
-Dwarf galaxies orbiting a galaxy similar to our own Milky Way.
+The formation of the Perseus cluster of galaxies recreated within
+the SIBELIUS-DARK simulations.
 
-<div class="videowrapper"><iframe width="100%" height="100%" src="http://icc.dur.ac.uk/giant_impacts/uranus_1e8_anim.mp4" frameborder="0" allowfullscreen></iframe>
+<div class="videowrapper"><iframe width="100%" height="100%" src="https://www.youtube.com/embed/AQmeomxvokM" frameborder="0" allowfullscreen></iframe>
 </div>
-A giant impact onto the young planet Uranus.
+A simulation of a plausible formation scenario for the moon as the
+result of an impact during the early days of our solar system.
 
 ## Why create SWIFT?