Seeing history from your backyard

💥 Just look to the stars.

Nov 29, 2025

with Ethan Siegel • November 29, 2025

Greetings readers,

This week marked American Thanksgiving: a harvest festival celebrated here in North America for around 400 years. What you may not know is that, on a more personal level, it marks my 19th anniversary of being together with my spouse. Make sure you take the time to let your loved ones know you care about and appreciate them; our time on this planet is shorter, more precious, and more fragile than most of us realize.

This week, I’ve got some classic stories from the vault that I thought I’d update and share with all of you, which I’m sure many of you are seeing for the first time (and which are all-new in their current incarnations). Have you ever wondered how far back in time it’s possible to see with just our naked eyes? While it’s true that most of what we can see is right here in our own galaxy, no more than a few hundred or thousand light-years away, some exceptions might surprise you with their remarkable power to look back in time. For decades, astronomers have wondered what came first: the stars or the black hole within massive galaxies? In 2022, we received a wonderful candidate answer of “the black hole.” Over the past 3 years, JWST data has validated and strengthened that idea, confirming the suspected solution to the ultimate cosmic chicken-and-egg riddle. The Moon’s two faces, near and far, don’t match, and we might be about to confirm an exciting theory for explaining it, which would be a remarkable advance.

And finally, I give you 10 things to be thankful for, not just on Thanksgiving but every day, and a throwback “Ask Ethan” that reminds us of the importance, on both cosmic and human scales, of investing in exploring the Universe. There is a grand cosmic story out there uniting us all, and I hope you enjoy exploring every moment of it!

All the best,
Ethan

EYES TO THE SKY

How far back in time can the naked eye see?

When we turn our attention to space, nearly all of the more distant objects that we can see, including almost everything beyond our own galaxy, require the use of tools, telescopes, or technologies that far surpass our naked eye’s capabilities. Nevertheless, there’s a remarkable set of things we can observe with the unaided eye, including, if we choose to look in the right place at the right time, things that are surprisingly far away.

Supermassive black holes came before stars in ancient galaxies

When we look back at the first ~billion years of cosmic history, we find hundreds of black holes weighing hundreds of millions or even billions of solar masses. It’s a longstanding puzzle: How did these black holes form so early and get so massive so quickly? After many years of research, we’ve finally cracked the Universe’s code.

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ASK ETHAN

Ask Ethan: What’s the point of exploring the Universe?

With so many problems in the world — war, poverty, hunger, disease, and much more — investing in exploring the Universe can sometimes feel frivolous. And yet, the value we get from engaging in pursuits that take us beyond our Earthly concerns can sometimes outstrip anything we’d gain from diverting resources away from those endeavors. Why invest in researching the Universe? Let’s dive in.

If you have a burning question about the Universe,
email startswithabang@gmail.com!

TWO-FACED

The Moon’s two faces don’t match, and we think we know why

In 1959, humanity finally flew a spacecraft around to the far side of the Moon and photographed it for the first time. What they didn’t expect was to see it look virtually unrecognizable to the Earth-facing side of the Moon we regularly see. For more than half a century, we’ve puzzled as to why these two sides of the same planetary body were so different. Thanks to the physics of early Earth, we might finally have the answer.

10 scientific phenomena to be thankful for every day

Here on American Thanksgiving, the fourth Thursday of every November, we set aside time to appreciate all we have in this world, and all the collective efforts that made it possible. So let’s take the time and look at the scientific rules that make our Universe possible, which is also worth appreciating.

Ethan Siegel, Ph.D., is an award-winning theoretical astrophysicist who's been writing Starts With a Bang since 2008. You can follow him on Twitter @StartsWithABang.