It will be interesting to see if we've just been missing these extra solar objects. I have doubts we'll actually do a project Lyra style fly-by though. Funding is going the opposite direction and all.
[0] http://orbitsimulator.com/BA/lyra.gif and https://i4is.org/project-lyra-a-solar-oberth-at-10-solar-rad...
It also means that "Oumuamua is an alien craft!" will almost certainly join in the ignoble legacy of "thinking the first instance of a new thing must be ALIENS" once we've detected hundreds of these (or more, depending on how sensitive we can get). You'd really think we'd be over this by now, but apparently not.
Consider what the implication would be if these are ET spacecraft. The galaxy would be absolute soaked in ETI. The Fermi argument would then bite maximally: why did we even evolve, if the galaxy has been so saturated? Why wasn't every single planet and asteroid used for colonies and resources ages ago?
It's important to realize that science fictional tropes of galaxies with everyone zooming around in spaceships having adventures are not consistent with what we observe.
Then I thought "now wait a minute...hold on..."
It's not just "New object, must be aliens!" It's "This thing doesn't fit our understanding of orbital motion for natural objects, aliens is actually a rational, if still unlikely, possible explanation."
[1] https://en.wikipedia.org/wiki/1I/%CA%BBOumuamua#Non-gravitat...
"Flat as a pancake" is one of several theoretical possibilities from its light curve, not a known fact about the object.
"Highly unusual" in space tends to mean "there are a bunch, but we haven't seen them until now". In 1992, exoplanets were "highly unusual". Now they're everywhere.
Why would we assume non-interstellar comets are always the same as interstellar comets? Conditions obviously are a little different when something is ejected from a system and then spends millions of years in interstellar space.
> Borisov had the same characteristics.
We have a sample size of three thus far. Making conclusions right now is like saying all extrasolar planets are large gas giants because the first three were.
Also, to date, zero of those things have been "aliens".
So rushing to declare the first instance of what was completely obviously a new class of objects as "aliens" because it didn't behave like what we expected is not rational, because we should expect that new things don't behave like we expect. The odds that the first one of these we detect is also the one from aliens is just not a good bet.
I'd bet a tidy sum of money that in 25 years it'll simply be common knowledge that these class of objects sometimes have those characteristics because of some characteristic special to them. Probably something to do with having a lot of things that turn to gasses and exert accelerations on the object because they were never blown off by the solar wind or something because of them being in deep space for millions of years. Might be most of them, might be a small-but-respectable fraction, but I bet in hindsight this is recorded in the history books right next to "pulsars are alien beacons!" and with the exact same tone of lightly sneering contempt we hold for that now. To which I can only say to the future, let the record show we did not all think it was aliens.
No, it doesn't mean that. What makes 'Oumuamua special is not the fact that we didn't see interstellar objects before. It's rather the fact that 'Oumuamua has highly unusual and hard to explain properties. Avi Loeb:
> ‘Oumuamua exhibited a non-gravitational acceleration of 4.92 ± 0.16 × 10^⁻6 m/s² that decreased proportionally to 1/r², where r represents the heliocentric distance, corresponding to a formal ~30 σ detection of non-gravitational acceleration (Micheli et al., 2018). The inverse-square relationship typically indicates radiation pressure or outgassing forces. However, despite extensive observations by the Spitzer Space Telescope, no carbon-based molecules, dust, or thermal emission indicative of cometary outgassing were detected (Trilling et al., 2018). Such a paradox — acceleration without observable mass loss — violates fundamental assumptions about how small bodies behave in the solar system.
> The object’s extreme geometry presented another unprecedented observation. ‘Oumuamua’s brightness varied by a factor of 10 during its 8-hour rotation period, indicating an extreme geometry with an aspect ratio exceeding 10:1 (Drahus et al., 2018; Meech et al., 2017). Such extreme elongation is unprecedented among known Solar System objects, leading to competing interpretations of either a cigar-shaped or pancake-like geometry (Belton et al., 2018; Luu et al., 2020; Mashchenko, 2019; Moro-Martín, 2019a,b; Zhang & Lin, 2020).
> More significantly, ‘Oumuamua entered the Solar System with a velocity remarkably close to the Local Standard of Rest (LSR). The object’s velocity before encountering the Solar System was within approximately 6 km/s of the local median stellar velocity and just 11 km/s from the LSR, with negligible radial and vertical Galactic motion (Mamajek, 2017). Fewer than 1 in 500 stars share such kinematics, making ‘Oumuamua’s near-stationary approach highly improbable for a naturally ejected object from a nearby star system (Loeb, 2022). Natural ejection mechanisms from planetary systems typically impart the host star’s peculiar velocity to expelled bodies, yet ‘Oumuamua appeared to originate from the most kinematically common frame of reference in our Galactic neighborhood (Loeb, 2022; Mamajek, 2017).
> The object’s rotational dynamics added another layer of complexity. ‘Oumuamua displayed non-principal axis rotation, exhibiting a tumbling motion rather than spinning around a single axis. Such a rotational state is unusual for an object that has been traveling through interstellar space for potentially billions of years, as collisions and internal friction should have damped its motion to simple rotation (Belton et al., 2018; Fraser et al., 2018).
> Finally, the object’s slightly red color differed from both typical comets and asteroids. Its spectral properties showed no absorption features that would indicate specific mineral compositions, making it difficult to determine its definite surface composition (Jewitt et al., 2017; Ye et al., 2017). This spectral ambiguity prevented researchers from determining surface composition through standard techniques, leaving the object’s fundamental nature — rocky, icy, or something else entirely — unresolved.
https://avi-loeb.medium.com/scientific-paradigm-resistance-e...
https://news.climate.columbia.edu/2024/04/09/was-it-an-alien...
> The signals consisted of so-called Rayleigh waves, high-frequency motions that travel on or just under the surface, and die out quickly as they radiate from their source. These can be generated by earthquakes, but also by human activities, including explosions, electrical signals and vehicles. The sources of these ones seemed to be moving, not stationary. Moreover, they appeared in a definite pattern: several per hour, almost invariably between 5am and 11pm local time.
> The team checked a Google Earth map showing the seismometer and its environs. It was just off the main road to the harbor, near the Manus Navy Health Center. The center seemed to be a locus of activity, with the signals moving back and forth from it, southwest to north―the same orientation as the road. Ekström’s conclusion: the seismicity was coming from trucks bumping along the irregular surface of the road, mostly in daytime, stopping at the health center to deliver or pick up people or supplies, then going back where they came from. That included the purported tremor from the meteor explosion.
https://www.independent.co.uk/news/world/americas/avi-loeb-i...
"Fewer than 1 in 500 stars share such kinematics" means 200+ million in our little galaxy alone.
Also seems like the thing to do, given that we are finding more than one of these now, is to build such a thing and have it on standby and look for one that's inbound so we can launch at the best window to reach it.
[0] https://en.wikipedia.org/wiki/3I/ATLAS
[1] https://en.wikipedia.org/wiki/3I/ATLAS#/media/File%3A3I_ATLA...
A lot of people are requesting discretionary time on telescopes trying to get observations in. The orbit will put us on the other side of the sun when 3I is nearest the sun in october, we can see it now and after it comes back out from behind the sun.
Unfortunately, right now the it is in a very crowded star field (IE, its close to the galactic plane, lots of stars in the background).
If you are interested in orbital dynamics, I have an open source rust/python package for accurate orbital calculations of asteroids/comets:
(assuming it hasn't interacted significantly with any other object in the solar system besides the sun)
You can approximate the orbits of basically everything in the solar system using 2-body mechanics (IE, ignore the planets). If you do this you get orbits which are elliptical (eccentricity <1), parabolic (eccentricity = 1), or hyperbolic (eccentricity>1).
If the object has an eccentricity above 1, its not bound to the solar system.
Many long period comets have eccentricity hovering near 1, often these long period comets will be on their first pass (sometimes only pass) through the solar system. These comets though usually dont get much above eccentricity of 1. The 3 interstellars we have spotted have had like 1.2 or bigger. This one is above eccentricity 6! Its moving fast.
Edit: I have heard that when the first interstellar was found it actually broke a lot of peoples code, as it was common to hard code limits to allowed eccentricities (or simply not support ecc>1 at all).
Only pass because of the eccentricity, or for some other reason?
many things are labeled historic, though some very very tiny number will actualy retain the power to inspire as this event will we have all dreamed of going into space to discover whatever is there, but as it turns out these interstelar objects are bringing us the only real physical evidence that we will ever get a good look at
Matt Holman's ASSIST (https://github.com/matthewholman/assist) struck me as a breath of fresh air, coming from openorb and its kin.
It does an OK job for impactors, but the integrator is tuned heavily for performance, and the tolerance defaults are not great for impactors.
I match jpl horizons for apophis to a few km, they have a lot more intense earth gravitational model then I care to implement, and by default I only include the 5 heaviest main belt asteroids, they have many more. That was the sweet spot for accuracy vs speed for me, overall accuracy goal is less than a few km over a decade.
TheBlight•4h ago