Sending Juno to fly past interstellar comet 3I/Atlas?
Hubble’s most recent image of comet 3I/Atlas.
Click for original image.
It’s all clickbait! In what appears to be an example of silliness, a scientist, Avi Loeb of Harvard, has proposed repurposing the Jupiter orbiter Juno by using its remaining fuel and its main engine (unused since 2016 because it is feared it will explode if ignited) to send the spacecraft on a path allowing it to fly past the interstellar comet 3I/Atlas that is presently zipping through out solar system.
Not surprisingly, a politician, congresswoman Anna Paulina Luna (R-Florida), immediately latched onto this idea to garner her own publicity.
Loeb believes Juno, which is scheduled to plunge into Jupiter’s atmosphere at the end of its mission in Sept. 2025, could be repurposed. He suggests using its remaining fuel to redirect it toward 3I/ATLAS when the object passes within about 34 million miles of Jupiter in March 2026.
Florida Congresswoman Anna Paulina Luna has backed the proposal in a letter [pdf] to interim NASA Administrator Sean Duffy, urging the agency to explore extending Juno’s mission. “It is recommended that NASA conduct a study to assess how much fuel is left in Juno’s engine, and I support an extension of the Juno mission at least until mid-March 2026 at a cost of about $15M per 6 months from the current expiration date of mid-September 2025,” Luna wrote.
The problem with this idea is that it isn’t realistic. Juno really doesn’t have sufficient fuel, and as I mentioned, its main engine is suspect, so suspect that the science team decided in 2016 to never use it again, thus leaving Juno in a higher than planned orbit that required twice as much time at Jupiter to get the same work done.
There is also one more reason to doubt Loeb’s proposal. He has also proposed that 3I/Atlas is an alien probe, ignoring or dismissing the images and data that make if very clear that it is nothing more than a comet, albeit interstellar in origin. It appears therefore that he might very well represent the quality of scientists that Harvard is hiring these days.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Hubble’s most recent image of comet 3I/Atlas.
Click for original image.
It’s all clickbait! In what appears to be an example of silliness, a scientist, Avi Loeb of Harvard, has proposed repurposing the Jupiter orbiter Juno by using its remaining fuel and its main engine (unused since 2016 because it is feared it will explode if ignited) to send the spacecraft on a path allowing it to fly past the interstellar comet 3I/Atlas that is presently zipping through out solar system.
Not surprisingly, a politician, congresswoman Anna Paulina Luna (R-Florida), immediately latched onto this idea to garner her own publicity.
Loeb believes Juno, which is scheduled to plunge into Jupiter’s atmosphere at the end of its mission in Sept. 2025, could be repurposed. He suggests using its remaining fuel to redirect it toward 3I/ATLAS when the object passes within about 34 million miles of Jupiter in March 2026.
Florida Congresswoman Anna Paulina Luna has backed the proposal in a letter [pdf] to interim NASA Administrator Sean Duffy, urging the agency to explore extending Juno’s mission. “It is recommended that NASA conduct a study to assess how much fuel is left in Juno’s engine, and I support an extension of the Juno mission at least until mid-March 2026 at a cost of about $15M per 6 months from the current expiration date of mid-September 2025,” Luna wrote.
The problem with this idea is that it isn’t realistic. Juno really doesn’t have sufficient fuel, and as I mentioned, its main engine is suspect, so suspect that the science team decided in 2016 to never use it again, thus leaving Juno in a higher than planned orbit that required twice as much time at Jupiter to get the same work done.
There is also one more reason to doubt Loeb’s proposal. He has also proposed that 3I/Atlas is an alien probe, ignoring or dismissing the images and data that make if very clear that it is nothing more than a comet, albeit interstellar in origin. It appears therefore that he might very well represent the quality of scientists that Harvard is hiring these days.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Loeb always brings me a smile. I like his Captain Ahab-like search for debris from another alien spaceship in the Pacific. Using a magnet on a sledge on a long line! Funny!
It would be risky–but Bereshete proved you don’t need much fuel if you use phasing loops. Juno’s extended mission is due to end, so this might be a cheap comet mission
I decided to do a quick netsearch of “Professor” Avi Loeb and Cydonia. He did not disappoint.
“Planets like Mars or Earth could have given multiple births to technological civilizations that were a billion years apart and hence were not aware of each other. Like stable parents, the planets recovered from the environmental impact of these civilizations over time”
He manages to combine Cydonia thinking with the Globull Climate Hoax.
https://journalnews.com.ph/harvard-scientist-believes-ancient-mars-civilization-could-be-source-of-uaps-from-odni-report/#gsc.tab=0
From what I recall, Loeb had satellite data from the DoD that showed the atmospheric entry of an object at interstellar speed. So he went to that location and tried to find microscopic fragments of its vaporization.
He didn’t say he expected to find an alien capsule, just perhaps so microscopic globules with unusual isotopic ratios. What’s so crazy about that?
I’ve consumed a lot of longer-form Avi Loeb, and he’s not as completely whacky as this might suggest.
-I’d suggest his appearances with Brian Keating, rather than Joe Rogan, although those are fun too.
He does have the newly formed Galileo Foundation, but no clue on who is Funding what.
Anton never has a bad word to say about anyone, but he was pretty upset with Avi Loeb in this recent video.
https://youtu.be/0gb33OpArfU?si=PR3CD27A-tNI_LnA
Crowl writes for Medium
https://medium.com/@crowlspace/space-drives-experiments-theories-85ff410e409e
I hear Loeb with David Livingston and John Batchelor frequently. I’ll say this for him, he’s quite enthusiastic about the topic.
Quote Bob… “He has also proposed that 3I/Atlas is an alien probe”…. No he didn’t, he proposed the idea as a “thought experiment” , which it certainly is… He is figuring out how to detect traces of exo-technology should they visit by design or accident, which to me seems like a valid area of research. He gets painted as a nut job, but actually researching his work shows he is a thoughtful and intelligent guy… We need folk willing to think a little outside the box… That is how our understanding of the universe improves…
“Ray van Dune said: From what I recall, Loeb had satellite data from the DoD that showed the atmospheric entry of an object at interstellar speed. So he went to that location and tried to find microscopic fragments of its vaporization.
He didn’t say he expected to find an alien capsule, just perhaps so microscopic globules with unusual isotopic ratios. What’s so crazy about that?”
Yes, he did say that. To confirm this, my old friend Gemini 2.5 told me,” Yes, Dr. Avi Loeb has explicitly and repeatedly implied that the debris he was hunting for could be from an alien spacecraft. The object in question, an interstellar meteor dubbed “IM1,” was notable for its high speed and material strength, which led Loeb to speculate about its artificial origin. He has stated in interviews and writings that the expedition’s goal was not just to find interstellar debris but also to look for “technosignatures” from a potential alien civilization. Loeb has even gone so far as to say that he believes the object may have been “artificially made by another civilization.” He has also drawn parallels between IM1 and another interstellar object, ‘Oumuamua, which he famously suggested could have been an alien solar sail.”
From my perspective, a examination of his method to recover the possible pieces of alien spacecraft was dubious from the start. Somehow, due to his gravitas he was able to raise millions from unnamed people to go on the voyage. First, he was using dubious data to build his trajectory map with giant error bars. Then he used a dubious method (a magnet) to pick up said debris (would an “alien” spacecraft use iron parts? Ha!). Then he used a ridiculously short search period to drag is magnet covering a negligible part of the “identified candidate ” area. He did not address all other sources of the particles he found or he could have predicted would be there (hundreds of tons of interplanetary particles fall on the entire Earth surface/sea every day). He did not even address the chain of custody problem where someone could be dropping interesting particles in the bucket to make the old professor happy.
I want to see Loeb in a Jacque Cousteau aqualung suit, digging among the rubble of the ocean floor for the alien parts. To quote the great diver: “The Sea, once it casts its spell, holds one in its net of wonder forever.” In the case of Loeb, millions of dollars wasted that could have been used to build some academic grade UFO detectors rather than sea travel.
Regardless of what anyone thinks of Prof. Loeb or Congresswoman Luna, I believe that Robert has identified what may be the real problem here. With its main thruster problems, can Juno, as Jeff Wright says, be turned into a “cheap comet mission”? And, even if technically feasible, is this a mission that is worth doing?
My thinking is that if it can be done, then *why not*, as this would apparently be our only chance to send a probe to intercept or at least get closer to this enigmatic object. Along with Robert (I’m guessing), I’m not expecting to see some kind of ancient, extraterrestrial artifact, but it sure would be nice to know more about 3I/Atlas, whatever it turns out to be. And, as in Juno’s original stay at Jupiter, such a redirected mission could carry along all of the citizen scientists who worked on imaging there — another chance for purposeful public involvement in space exploration.
PS — Thanks to Edward for sharing the link to the Delta-V map of the Solar System in the comments section of an earlier post. Juno is now in Jupiter’s gravity well, so how much fuel, I’m wondering, would it take to move it. Likewise, could Juno slingshot off one or more of the Galilean moons? Can anyone supply a rough, back of the envelope analysis of this?
PPS — To Robert: Sometimes clickbait stuff can be “good” if it encourages people to think about things that they might ordinarily overlook. My situation in this case. (After the clickbait experience, go to Behind the Black for the real deal.)
The old saying is “show your work.”
Well–here it is:
https://arxiv.org/html/2507.21402v1
“The optimal option involves a Jupiter Oberth Maneuver which requires an application of Delta Vee on September 9, 2025, only 8 days prior to the originally intended termination date for Juno’s plunge into the atmosphere of Jupiter.”
You couldn’t have timed this better.
“Having delivered this thrust to diminish Juno’s altitude, a further Delta Vee is subsequently delivered, constituting a Jupiter Oberth Maneuver and resulting in an eventual intercept of the target 3I/ATLAS on March 14, 2026.”
It is very difficult to find actual source quotes from Loeb, but I did find this …
“Loeb emphasizes that this hypothesis serves more as an intellectual experiment than a definitive claim: “the most likely outcome is that 3I/ATLAS is a completely natural interstellar object”, he states ”
Source. https://voice.lapaas.com/3i-atlas-alien-spacecraft-earth/
He’s definitely got some wild ideas… But as I said, thinking outside the box is important… Science will prove him correct or wrong.. and probably the latter, but if you don’t even try you will never succeed.
As for repurposing Juno… If the mission scientists consider it possible, then why not try? It has achieved it’s goals around Jupiter so a chance to view an interstellar visitor ( relatively) close up seems like a mission to take a punt on.
Attempting this repurposed mission has a less obvious learning benefit: The team gets to see if the main engine actually does explode when they use it, although they may be planning this anyway before sending Juno into Jupiter.
I think that Avi Loeb is a very smart and capable astrophysicist, but this episode (even with Lee’s caveats and clarifications) exemplifies the truism that experts can be extraordinarily ignorant outside of their areas of expertise. Also, he’s been bitten by the UFO bug.
3I/Atlas is pretty obviously a comet, but it would still be worthwhile to send a probe to do a flyby. But if we want to do that, we are going to have to launch something for just that purpose.
Jeff — Thank you for sharing and “showing their work”! (That sure ain’t clickbait.)
This is the kind of “peek behind the curtain” for non-engineers — again thanks — reality-based discussion that this forum makes possible, and I am thankful that we have it. Ditto for Mr. Batchelor’s program. Would that — today’s “if only” moment — more people in media were as interested in making the world more comprehensible.
https://en.wikipedia.org/wiki/Flammarion_engraving#/media/File:Flammarion.jpg
Juno is to take a plunge soon anyway–and it may be too late to get end-of-life assets at Mars pre-positioned.
If this is to be done–twere well if it is done quickly.
Oumuamua would be in my “grey basket to quote Friedman.
The Teton Event too—most assume that it was a small asteroid. That is likely true.
But it was to make a resonant return in the 1990s after doing a thousand kilometer aerobrake of sorts.
A.C. Clarke’s Mysterious World showed the Super-8 footage of this Great Daylight Fireball of 1972.
The contrail looked quite steady.
That needed a mission.
Brian Keating with
Eric Weinstein and Avi Loeb (March 2025)
https://youtu.be/2B_O0fnJyZs
1:25:19
Avi Loeb has shown himself to be a poor scientist. One does not need to be an expert in a particular field to understand the principles of Science and the scientific method.
He is a media hound and publicity seeker. He will come up with the most outrageous claims and proposals so he can get headlines. He might as well be a politician. And for the reason that he has built up a huge resume of papers with lots of coauthors who sit at his feet because they got their PhDs with his help and high, tenured position in academia, he is assumed to be a good bet. He is a horrible example for young academics.
https://ui.adsabs.harvard.edu/abs/2022arXiv221200839T/abstract
https://arxiv.org/pdf/2212.00839
https://arxiv.org/pdf/2208.00092
I cannot ignore that he got some “angel” investor to give him millions of dollars for a useless and hopeless endeavor to find remains of an alien spacecraft. Can you imagine it? “Put everything on red 34” I guess is the motto of these guys!
A paper he coauthored prior to his trip states: “A recently announced ocean expedition will retrieve any extant fragments by towing a magnetic sled across a 10 km x 10 km area of ocean floor approximately 300 km north of Manus Island.”
Any? Well, that is pretty thorough!
Assuming 3.3km/hr realistic tow speed and 1 meter magnet width, this will not cover the entire 10km by 10km. You have to do 1000 passes of the 1 m magnet to cover ONLY a 1 km long swath of 1 km^2 area (not 100km^2). That is a distance travelled is 1000km (1000X 1km). A tremendously boring long trip over a tiny area. At 3.3 km/hr that is 303 hours or 12 days. Their entire mission was 7 days. So, the best he could is less than 1/100 of the 10km by 10km search area.
Now note the object, the alien object, from an interstellar alien spaceship, is only 0.5 m big. Tiny aliens. But even if just a robotic probe, made of steel? How primitive.
He offered an estimate as to how many fragments exist within the search area prior to his mission sailing: 29,000. With the minimum size being as small as .004 gram which is about the mass of a grain of sand. He also modifies the analysis for a source body that is made of steel. The total number is thus reduced down to 2,240.
If looking over 100km^2 for at least one of 29,000 fragments sounds hard, it is. With a equal distribution of fragments over 100km^2 that means 290 fragments per square kilometer. So, you need to cover 3448 m^2 just to pick up 1 tiny particle. But the tow sled dragged along the ocean floor is 1m wide by 2m long in size with a big magnet on it to pick up the hopefully magnetic alien spaceship metal or likely meteorite iron. The 1m wide platform has to do 1 pass along a 3.4 km long search area to pick up one fragment if magnetic. For the steel fragments case, it is 44 km just to pick up one. So, if distributed equally over 10km by 10km , it seems doable to get at least a few. If in the right area. But….
He shows in a figure a rather precise map of the trajectory of fragments. No probabilistic dispersion angles. What about an error bar? Any error in the trajectory or sensor data? We have this sort of thing for hurricane paths or satellite reentry. What I would expect is a map with a large set of paths of the interstellar object in the atmosphere. But we have one nice straight line. His lack of trust in the military regarding UFOs was countered by his full trust in the military data for this object.
He uses iron and steel for the assumed fragment composition. Clearly one does not use steel unless one implies an alien spaceship. He did not assume some strong non-ferrous material that cannot be picked up conveniently by magnets. This is sort of like the drunk looking under a street light for his keys despite losing them beyond the street light because at least he can see the ground.
And, to repeat, he did not mention the accrual of interplanetary dust onto Earth at 40 tons a day rate and how that adds confusion to his Science.
One wonders how he got such a good rep. Maybe he can do fancy math. Enough differential equations and integrals will do it every time. So, whenever he shows up with a new proclamation of possible aliens, I view it with jaundiced eye.
There are all kinds of metal modules on the sea floor anyway. No real way to ascertain info as to that “debris'” provenance.
The only way to KNOW something came from space is to see it in space. Hackaday profiled an individual of the MAKE movement who fabricated what looked like meteor metal (July 29, 2025 hackaday).
This is sort of like the drunk looking under a street light for his keys despite losing them beyond the street light because at least he can see the ground.
It is and it is not. It’s very difficult to go flying about in space looking for stuff. It’s somewhat difficult to build telescopes to find stuff in space. It’s relatively easy to look for space stuff that has crashed (or deliberately landed) on Earth.
To use the analogy, we don’t know where the keys were dropped, so let’s check the easy-to-search place, first.
I don’t expect anyone to find anything, but that’s not an excuse to not look. I wouldn’t have expected relatively or quantum chromodynamics, either. I’m not going to donate and I don’t think it should be a tax-payer funded effort, but if people want to spend their money on the search? Well, it’s their money; spend it as you wish.
Mark Sizer says: “It’s relatively easy to look for space stuff that has crashed (or deliberately landed) on Earth.”
One of the parts of the “science” is to get a baseline. He did not get a “baseline” by sampling where he did NOT think the incoming alien spaceship (again I repeat only 1.5 foot by 1.5 foot in size) had spread its particles. If he had, he would have discovered that everywhere in the ocean are these particles. What a discovery! Alien spaceships have fallen apart everywhere and are just there for the recovery with a bucket or a magnet! Go to your nearby lake and scoop! And if you can find the brilliant “angel” investors (that brought us the dot.com bubble), maybe you can do it in style with a nice ship and sailor hat and rare-earth magnet. A fool and their money are soon parted makes alot of sense.
Loeb should stick to what he knows: astrophysics. It is less controversial. Has he done all that can be done in that area? Is it boring or something? Maybe no one wants to fund it because it gets no headlines.