A galaxy collision got me digging, Goodbye Tiktok, Project for Awesome

Sometimes mistakes lead to cool astronomy stuff.

In partnership with

The Trifid Nebula looks like a red flower with dark lines converging on its center, surrounded by pale blue gas and countless stars.

The Trifid Nebula and environs. Credit: RubinObs/NOIRLab/SLAC/NSF/DOE/AURA

February 2, 2026 Issue #992

When galaxies and catalogs collide

A pair of interacting galaxies with confusing distances

European Space Agency’s Euclid space telescope is a phenomenal observatory, designed to map the sky at high-resolution and accurately measure the location, brightness, and distance of billions of galaxies — yes, billions. The goal is to make a 3D map of the Universe so we can better understand the nature of dark matter and dark energy.

The images it takes are amazing (like here, here, and I describe the mission more in that latter link). ESA recently posted a lovely shot of a pair of galaxies, which led me down a bit of a rabbit hole:

Oooo, pretty! NGC 646 is the wide-flung spiral galaxy on the right, and PGC 6014 is the more compact galaxy on the left, at the end of one of NGC 646’s arms.

In fact that placement made me suspicious immediately: galaxies collide, and when they do their mutual gravity distorts one or both. Spiral arms can be drawn out of a galaxy, stretching them like taffy as the other galaxy pulls on them. That image of NGC 646 and PGC 6014 very strongly implies that’s what’s going on here.

But I was baffled when I read the ESA press release. It said the galaxies were 40 million light-years apart! That’s way too far for them to interact; galaxies are tens or of thousands or a hundred thousand light-years across. If they were that far apart then I had no idea what I was seeing.

So I looked up the galaxies’ info on SIMBAD, a database of astronomical objects. I grabbed the galaxies’ redshifts — how rapidly they’re receding from us as the Universe expands — and converted them to distances. What I got surprised me: they’re about 4 million light-years apart, not 40.

I contacted ESA and they told me what happened: they used the NED database, which apparently has some older measurements, which may be why the numbers are more iffy. SIMBAD uses more current measurements, so is probably more accurate. They corrected the press release.

I’m glad I checked SIMBAD! Had I checked NED I would’ve been totally stumped.

Still, four million light-years is a long way, and that still is surprising they’re interacting. But I found a paper that mentions the pair, and it says this is a “flyby interaction”, which makes more sense; they’re not merging or anything, but flying past each other. The interaction was cosmically brief, but enough to stretch NGC 646. Coincidentally, given their sizes, they must be moving along a line pointing right at us, otherwise they’d appear much farther apart. Cool. 

This is a cautionary tale, though, and shows exactly why I dig deeper into stories before writing about them. This was an honest error caught by luck, and one I or anyone could’ve made (and have, of course, because mistakes are inevitable). But in fact I sometimes enjoy this when it happens, because it gives me an excuse to dig even deeper than I usually do to try to figure out what’s going on. Science advances by making mistakes — as this guy says so well — and that’s how we learn.

Why is everyone launching a newsletter?

Because it’s how creators turn attention into an owned audience, and an audience into a real, compounding business.

The smartest creators aren’t chasing followers. They’re building lists. And they’re building them on beehiiv, where growth, monetization, and ownership are built in from day one.

If you’re serious about turning what you know into something you own, there’s no better place to start. Find out why the fastest-growing newsletters choose beehiiv.

And for a limited time, take advantage of 30% off your first 3 months with code LIST30.

<sigh>Goodbye, Tiktok

Another social medium falls to right-wing oligarchs

I just deleted my Tiktok account.

And yeah, I’m upset about it. Ticked, you might say.

People mock Tiktok for being shallow, full of lip-synching and weird meme dancing and dangerous viral stunts. And sure, that’s there, but there’s also a lot of interesting science communication, fun math demos, history lessons, civic info, comedy, and political lessons. I quite like watching it. I even made a few videos myself to test the waters. 

But that’s gone now. The app was owned by China — and still is — but Trump and his regime forced the company to splinter off and form a majority US-owned version (this whole mess was actually started by Biden with a bipartisan bill, which shows that gross ignorance over how the internet works knows no party). The galling irony and typical hypocrisy of this is that they claimed having a foreign government own the app is a threat to privacy and national security, but of course the new owners have already made changes that give users even less privacy and ownership over their data.

One of the companies with a majority share is Oracle, owned by Larry Ellison. This billionaire is the one behind CBS’s rightward lurch, and he’s a big buddy of Trump’s. That alone is enough to make me dump the app.

I deleted my Facebook in 2018, the rest of Meta (Threads and Instagram) in 2025, and Twitter in 2023. And now Tiktok. I’m really, really tired of billionaires running and ruining everything… and of course it’s not just social media, but media in general, and the ramming of useless AI down our throats, and politics, and and and.

So the only social medium I use now is Bluesky. There have been some unsettling decisions by the administrators there, but overall I’m happy with it, and will continue to use it. Given the current political climate it’s currently overwhelmingly about ICE and the power grab by the far-right, but there is still a lot discussion about science, astronomy, and more. It’s where I can still promote this newsletter, show people amazing cosmic beauty and awe, and talk and joke with my friends, so that’s where you can generally find me. And who knows; there have been rumblings of independent apps to replace Tiktok. I haven’t seen much progress there, but I hope that in the next few months something will turn up.

Hear me chatting with John Green on Valentine’s Day

It’s our yearly promotion of Project for Awesome

And since I don’t want to leave this issue on such a sour note, how about some positivity?

My friend John Green is an author and videoer (I’m not sure that’s a word, but it fits) and all-around good guy. Together with his brother Hank they do amazing work raising money for extremely worthy causes as part of their Project For Awesome initiative. Every year they put on a marathon video livestream where they talk with people and take donations. I’ve been a guest for several years now, and this year I’ll be on live with John on February 14 at 11:15 Eastern US time. I don’t know exactly what we’ll talk about, but I may rant a bit about Betelgeuse.

I also have donated 30 small meteorites to be given away to people who donate, so be sure to tune in and help decrease world suck (which is their motto)!

Et alia

You can email me at [email protected] (though replies can take a while), and all my social media outlets are gathered together at about.me. Also, if you don’t already, please subscribe to this newsletter! And feel free to tell a friend or nine, too. Thanks!

Reply

or to participate.