Monday Astronomy Picture Ponderings (MAPPs) 2/21/2022

A Cosmic Dance of Galaxies

A pair of interacting galaxies called Arp 273 by NASA, ESA and the Hubble Heritage Team, pulled by the author from the Astropix collection. The larger, top galaxy is a spiral, similar to our own Milky Way, while the smaller one at the bottom is more elliptical. Both show signs of distortion due to their interactions with each other. Image Use Policy: Creative Commons Attribution 4.0 International License.

Welcome back to the Monday Astronomy Picture Ponderings (MAPPs) series where every Monday I pick one of NASA’s Astronomy Picture of the Day (APOD) entries from the past seven days to focus on in some way.

A snapshot of a cosmic dance acts out before our eyes. We see the elements of movement, the fuzziness hinting at motion like so many action shots we’ve seen before of dances, races, and games played out here on Earth. Their swinging arms reach toward each other, reminiscent of past embraces and foretelling future ones.

The image hints at the larger dance, but it is just a snapshot, a single moment within the dance itself, simply one step in the choreography. You can feel how the dancers are spinning around each other, the smaller one twirling away from the larger one, most likely after being previously close together.

And yet this is no samba or waltz or jig. And the dancers are inconceivably large and complex. The dance itself takes place over millions and billions of years, as opposed to minutes, slowly sashaying across the night sky.

Just one tiny snapshot of a much longer dance choreography, one in which you or I will likely never see the next move, but our descendants might see some movement, some change.

And yet, even what we are seeing occurred long, long ago, and far, far away as the actual dance takes place over 300 million light-years away, a measurement of both time and distance.

And yet, the dance also tells our own future. For we are part of the great cosmic dance. We even have a partner as well, slightly out of sync with these two.

We watch our partner, Andromeda, waiting to have our turn to be united in our own couple’s dance in billions of years. Waiting to twirl, come together, and part again and again in our own dance.

A beautiful, moving performance when viewed from quite a distance and yet leaving trails of destruction within its actual limbs. Stars and planets are torn apart and collide as part of the ever-moving progress of time and the universe.

We humans will hopefully no longer be here in one way or another when our own Milky Way’s dance…