怎样用CSS画一个旋转的地球

<style type="text/css”>
.canvas {
  background-color: #111;
  padding: 30px;
  clear: both;
}
#earth {
  width: 300px;
  height: 300px;
  background: url(http://www.noirextreme.com/digital/Earth-Color4096.jpg);
  border-radius: 50%;
  background-size: 610px;
  box-shadow: inset 8px 36px 80px 36px rgb(0, 0, 0), inset -6px 0 12px 4px rgba(255, 255, 255, 0.3);
  animation-name: rotate;
  animation-duration: 12s;
  animation-iteration-count: infinite;
  animation-timing-function: linear;
  -webkit-animation-name: rotate;
 -webkit-animation-duration: 12s;
 -webkit-animation-iteration-count: infinite;
 -webkit-animation-timing-function: linear;
}
@keyframes rotate {
  from {
    background-position: 0px 0px;
  }
  to {
    background-position: 610px 0px;
  }
}
@-webkit-keyframes rotate {
  from {
    background-position: 0px 0px;
  }
  to {
    background-position: 610px 0px;
  }
}
</style>
<div class="canvas”>
<div id="earth”> </div>
</div>