Coronal loops 30 times the size of earth above sun photosphere. Solar plasma loops are above the visible sun surface. The TRACE satellite recorded these in the extreme ultra-violet. Credit: NASA.
What is an Atomic Clock?
The watches we wear on our wrists or the clocks we put on our walls are not atomic clocks. There are not all that many true atomic clocks - and they tend to be rather large and expensive. So, unless it looks something like the picture alongside from the National Institute for Standards and Technology