Heron&Fox Photo<p>Sometimes when <a href="https://universeodon.com/tags/rockets" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>rockets</span></a> cross through a colder layer of air, their exhaust condenses, creating a <a href="https://universeodon.com/tags/contrail" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>contrail</span></a>. <br>The high-level <a href="https://universeodon.com/tags/winds" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>winds</span></a> blow the contrail around, with different wind directions at different altitudes, often producing a <a href="https://universeodon.com/tags/corkscrew" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>corkscrew</span></a> effect, as in this <a href="https://universeodon.com/tags/DeltIVHeavy" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>DeltIVHeavy</span></a> <a href="https://universeodon.com/tags/launch" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>launch</span></a> from 2016.</p><p><a href="https://universeodon.com/tags/DeltaIV" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>DeltaIV</span></a> <a href="https://universeodon.com/tags/UnitedLaunchAlliace" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>UnitedLaunchAlliace</span></a> <a href="https://universeodon.com/tags/ULA" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>ULA</span></a></p>