I think that as far as the cosmos affecting the earth goes, people are thinking in the wrong way. There’s not really a need to hope that a supernova might have some extreme influences on the earth.

We are already connected with the cosmos in the deepest ways. The atoms in your body and mine and really everything heavier than hydrogen and helium were all created in the interiors of the stars. You and I are the dead embers of stellar furnaces where the atoms were “cooked” by fusion processes.

That’s already a very close connect.

The cosmos’s dark matter was crucial in shaping the galaxies - you can’t make a galaxy without the gravitational influence of the dark matter. And the galaxies are basically star factories, squeezing together gas and dust in their gravitation and creating stars from there.

So the existence of planets with heavy elements is related to hot interiors of stars, which are made with the help of galaxies, which are made with the help of the dark matter.

As Carl Sagan said, you ARE the cosmos, in a very very real sense.

And so as I said, we don’t need to have material or light from supernova crash into our planet physically and wreck our atmosphere in order to already have an intimate connect with the universe.

Having said that… What IS the case for physical and material connections with nearby neighbors? Well, the asteroids and comets may strike us…. or NOT strike us! One thing that can sometimes block them and “save“ us is the planet Jupiter with its massive gravity as it helps deflect dangerous objects from crowding up the innner solar system.

More close to home, the moon gives us the tides, AND it helps to stabilize our axis of rotation, thereby keeping our seasons from getting too hot or too cold or too mild. Mars has NO large moon and it’s axis HAS varied wildly giving rise to wildly varying seasons over millions of years…

Okay, so what about the stars? CAN they physically affect the Earth? Yes, because the light of the Milky Way can be seen and detected and used for navigation by human beings on earth and even by some species of animals who have evolved to use, it’s light.

The stars are generally incredibly remote from one another in comparison to their physical diameters - the typical diameter is maybe one million times smaller than the distance between. The absolute amount of light generated by a star in our sky is essentially miniscule on the scale of light sources in our immediate environs.

But, what about a supernova? There are two factors here - how far away the beast is from earth and also sits intrinsic power. For the vast majority of supernova, their location will be maybe a few tens of thousands of light years remote, which is far too distant to “damage“ us. I would guess that the only time there would be any “worry” would be if, by chance an extremely close star, say just a few tens of light years away were to detonate. But such a thing is remarkably rare - maybe once per trillion years I believe.