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The merger of neutron stars expel a luminous fireball of heavy-elements, which can be observed as a so-called kilonova. The kilonova's geometry is a key diagnostic of the merger and is dictated by the properties of ultra-dense matter, the energetics of the colliding stars and the formation of a black hole. In this talk we will present the first geometrical constraints, which are derived from the spectral lines and the blackbody nature from kilonova spectra taken in 2017. While current hydrodynamical merger models typically show aspherical ejecta, these observations suggest that the kilonova is highly spherical in early epochs. We present these observations, discuss their startling implications and the opportunities these observations allow for probing these most extreme of physical environments.