Jason Wright

My textbook on SETI is published! I hope you like it! Please see if your libraries offer a free download—mine does! iopscience.iop.org/book/mono/978-…

@PlanetaryVictor Please ask your university librarians for help. You can email me if they say there’s no way you can download it through them.

@Astro_Wright I'm unable to download it

My textbook on SETI is published! I hope you like it! Please see if your libraries offer a free download—mine does! iopscience.iop.org/book/mono/978-…

@danaunseen I am no expert, but a very quick search reveals that comet Hale-Bopp famously had a conspicuous antitail. Antitails are apparently most obvious when Earth is in their orbital plane, so It makes sense 3I/Atlas would have one since it is in the ecliptic. link.springer.com/article/10.102…

Thank you. I looked into a few historical comets that were observed with anti-tails. But the ones I looked up all were later confirmed as false-positives. For example, Arend–Roland turned out to be a canonical geometric illusion. The closest comet I found that was thought to have a true anti-tail was C/2014 Q2, however even in this case it was not persistent only existing briefly. It appears the record shows persistent anti-tails are not a thing. Are there others that were indeed proven persistent and not an illusion? One other observation of 3i/atlas that I don't think can be explained is that the objects nucleus axis rotation has been aligned to the direction of the sun. This was true when rotation was first observed (5 AU) and well as now (after its perihelion). In a vacuum, one could speculate that it was by pure chance (as small odds as that might be). But in conjunction with other anomalies, its harder to buy.

@Astro_Wright Hello Jason. I recently read your November post ("Loeb's 3I/ATLAS 'Anomalies' Explained"), where you provided natural explanations for several of the points raised by Avi Loeb. However, Professor Loeb has recently expanded his list to "14 anomalies" in a December 2025 Medium article ("Why is the Anti-Tail Sunward-Jet of 3I/ATLAS Tightly Collimated?" avi-loeb.medium.com/why-is-the-ant…). He argues that the object features a "tightly collimated" sunward jet/anti-tail that, unlike those seen in typical comets, is not merely a geometric optical illusion. He specifically highlights the periodic wobble and the maintenance of this jet's orientation as unprecedented evidence of artificial origin. Given your expertise, I would value your opinion on two points: The Cumulative Case: While individual anomalies might have natural explanations, does the totality of these 14 distinct statistical outliers shift the Bayesian probability significantly in your view? The Anti-Tail: Is the "tightly collimated" and wobbling nature of this specific anti-tail indeed as unique as claimed, or are there historical precedents in cometary physics that can account for this behavior without invoking technology? My understanding is that all prior anti-tail observations were line of sight illusions and NOT true anti-tails, whereas, 3i/Atlas is in fact a true anti-tail. Thank you for your time and for your continued efforts in communicating science to the public.

@danaunseen It is worth noting that all of his “anomalies” are things comets are known to do, and the vast majority of them are not things you would expect a spacecraft to do. E.g.: many comets have been known to have true anti-tails, and their physics has been well understood for decades.

@danaunseen I admit, I have not been able to keep up with all of his claims and misunderstandings about the comet since my latest posts. Given his track record and obvious modus operandi I don’t think it’s worth paying any attention to him anymore.

To be clear, I think there are lots of engineering challenges to putting massive amounts of compute space that mean it might never be profitable. And listing “cooling“ as a reason it’s easier is wrong. Cooling is space is hard. But not, I think, the showstopper.

Yes, it is much harder to cool things in space than on Earth. But you also need to collect energy with solar panels, which actually gives you all the area you need to do the radiation. I am not sure our tech lords understand this, but it’s actually not a huge showstopper?

@redplanet00 @DrPhiltill Yes! But also, they don’t have to be very heavy, and space is big. I think the solar panels are the bigger problem, frankly!

@Astro_Wright @DrPhiltill Dumping the heat generated will require football fields of passive radiators into space !

My vibe read from Phil is that space offers a few factor of ~2 advantages (continuous daylight) and *lots* of big disadvantages to the engineering. The biggest advantage is practical: space avoids the high cost and delay of regulation and feedback on the environment on Earth.

If we build a Dyson sphere, this paper explores the outer limits of how much computation it could possibly do, and how we might find such things around other stars.

Since the waste heat associated with computers and space seems to be all the rage on social media these days, I’ll point out this paper I wrote on the theoretical maximum number of computations. You can do giving that it’s hard to cool things in space: iopscience.iop.org/article/10.384…

I used to believe this so I never lied to my kids about it but they "forgot" and ended up believing in him anyway and enjoyed the whole Santa thing even though they "knew" he was fake. Turns out kids are very, very good at understanding play "truths". It's just not a big deal.

Harvard Astronomer Burned in the Funny Pages gocomics.com/lio/2025/12/08

The 2nd PRIMA GO Science Book is out! So excited to see so many use cases for an All-Sky Survey. The best FIR map in some ways is still from IRAS—we're overdue for an orders-of-mag. leap in FIR imaging sensitivity and resolution across the entire sky! ui.adsabs.harvard.edu/abs/2025arXiv2…

Really interesting analysis here on how claims get amplified by our current media environment (and a rebuttal of sorts to those who argue that Avi Loeb's alien spacecraft hype is good because any science engagement is good engagement): cip.uw.edu/2025/12/03/3i-…

Come work with us at Penn State! The @PSU_CEHW is hiring postdocs, and welcomes applicants who can make connections with its sibling centers like @PSETI_Center doing SETI, Astrobiology, and Planetary Systems Science: aas.org/jobregister/ad…

The Moon’s two faces don’t match, and we think we know why The lunar far side is maria-poor, crater-rich, and full of highlands. With our first far side samples now in Earth laboratories, our leading explanation awaits its big test. bigthink.com/starts-with-a-…

@WR4NYGov @8teAPi @dwarkesh_sp The idea of using something in space to extend baselines for interferometry has only been tried once, as far as I know. Nikolai Kardashev (of the scale fame) championed RadioAstron, a Russian space radio telescope that did this!

@WR4NYGov @8teAPi @dwarkesh_sp Neat idea, but it would not work. Not only are those satellites not stable platforms for telescopes, they are not very far away from the Earth! They are only a few hundred miles off the surface, and the Earth is thousands of miles across.

Dyson Sphere by 2040? > Paul Christiano gave a 15% probability a Dyson Sphere by 2040 on @dwarkesh_sp > So I invited @Astro_Wright , astronomer and astrophysicist at Penn State, a specialist on detecting alien technological signatures to figure out whether it would be possible Highlights: On The Physics of Dyson Spheres > On the Ultimate Limiter - Cooling: "The only thing you can do is put out radiators and let the heat radiate away... you don't have a river nearby, you can't do water cooling, you can't blow fans across it. There's no air." > On Building Them Hot, Not Cold: "I actually expect the Dyson spheres to be as hot as possible if they're maximizing computation... I think these things will be room temperature or warmer." On Building A Dyson Sphere > On Disassembling Jupiter: "You could disassemble Jupiter and build a Dyson sphere... He [Freeman Dyson] worked out the details like, it's totally possible to disassemble a planet." > On the Impossibility of a Quick Dyson Sphere: "It is literally impossible to build a Dyson sphere around the sun that quickly [in 50 years]... It's not that I'm not being imaginative. It's that there's not enough mass. The mass is in Jupiter." > On the Sheer Energy Required: "If you took all the energy the sun puts out for 50 years and with perfect efficiency used it to lift mass off of Jupiter, you would still not have enough time." > On the Key Technology Required: "I think you have to invoke exponential growth. You need some way to have a runaway exponential that mines so much material, builds so many things... I think it's self-replicating machines, Von Neumann machines." On Detecting Alien Civilizations > On the Impossibility of Hiding: "It's very hard to hide the fact that you're using energy... you can't keep it, you'll melt everything. And when you get rid of it, it'll be obvious." > On How Easy They Are to Find: "Such a thing would be extremely detectable... Even if it only captured 1 or 2% of a star's light altogether, that would still be quite obvious. It would look quite anomalous." > On Finding a Hidden Civilization: "You can put on infrared goggles and you'll see who's got the heat on. Like the houses that that are warm on the inside... you can see the heat coming off of those houses." > On Ruling Out Super-Civilizations: "We were able to show that out of the 100,000 closest galaxies to the Milky Way, there aren't any of those [Type III civilizations]." On The Space Industry Wrecking Science > On the Perfect Spot for Alien Hunting: "Putting a radio telescope on the far side of the moon would be amazing... the moon acts as a shield and there's no radio frequency interference." > On the Threat to the Lunar Far Side: "As soon as you say, 'Alright, we want to build something on the far side of the moon,' everyone's like, 'Great, let's build the infrastructure'... and they set up all this wireless communication across the moon. And you're like, 'That defeats the entire purpose.'" > On the Impact of Starlink on Science: "Starlink went up and just completely wrecked all of our plans for astronomy... And now every time it takes a picture, it gets 'Starlinked.' That's what we call it. Big old streaks through every image." > On the Race to Study Mars: "We kind of got to hurry up and do all of our life detection experiments before boots hit the ground there... As soon as people go to Mars, we will contaminate it." This was by far the best pod I've done so far. Links below: