For generations most things people could see in the heavens never changed shape. The Moon and some comets were obvious exceptions. Only recently has it been possible to see, with the aid of technology, the dynamism
of the Sun's atmosphere
, or movement
in the clouds of Jupiter
But images of change at larger scales —
such as animations of galaxy evolution and distribution here
and here —
remain artefacts of reason, imagination and ingenuity rather than direct observation.
Our experience of stars, nebulae and supernovae is still mediated through static though often spectacular
photographs. Given how slowly
the stars seem to change during a human lifetime this seems almost inevitable.
In this context, a clip showing fifteen years' expansion
of the Tycho Brache Supernova remnant feels like something particularly remarkable, at least to me. At two seconds (blink and you'll miss it), it is the same length as the 1888 Roundhay Garden Scene
, and no less momentous.