Ghostly Galaxies

When looking out into the starry night

The blackness that we see is just a mask;

This shrouded veil conceals our darkest light,

And stores our nameless theories in its cask.

It’s absence shapes and bends what can be seen,

And sets us on a righteous, testing task

To try and map the darkness in between.

We try in vein to find your missing key,

To glimpse the ghost that’s lost in the machine.

Yet whilst your spectral stars are faint to see,

There’s nothing hidden in your galaxy.

This is a terza rima, inspired by recent research about a newly discovered galaxy that has been observed to be almost entirely devoid of dark matter.

Dark matter neither emits nor absorbs light or other forms of electromagnetic energy, making it very difficult to detect. However, astronomers know it exists because of the gravitational force that it exerts on the things that we can see. By observing this gravitational effect, scientists estimate that dark matter makes up approximately 23% of our Universe.

Galaxy NGC1052-DF2 is an ultra-diffuse galaxy, so classified because of its large size and faint appearance. By using data from the Gemini North and W. M. Keck Observatories, as well as the Hubble Space Telescope, researchers were able to show that almost all of the mass in this galaxy can be attributed to the mass of its visible stars, meaning that it appears to contain almost no dark matter. Finding a galaxy without dark matter is unexpected, and new theories are now needed to explain how a galaxy such as NGC1052-DF2 came into existence.

An audio version of this poem can be heard here and you can find out more about the research by reading the Gemini Observatory press release.