I found this aside on one of the graphics rather surprising:
> Sometime in the next 2000 years, the Sun is expected to leave a local cloud of gas and dust. After that, it may enter the G cloud. If it is denser, it would squash the protective magnetic bubble of the heliosphere, potentially exposing the Solar System to a barrage of cosmic rays.
Mostly surprised that I hadn't heard more about this. 2000 years is practically tomorrow in cosmological time!
I’m assuming our solar system has moved through various interstellar mediums throughout history, and from reading above it sounds non-trivial. Is it? Do we know anything about how this may have influenced the development of Earth?
Learning this gives me a very “oh my god we’re hurtling through space!” feeing that I haven’t felt in a long time.
> > If it is denser, it would squash the protective magnetic bubble of the heliosphere, potentially exposing the Solar System to a barrage of cosmic rays.
That seems highly exaggerated. The Wikipedia article you mentioned is more sober:
> The Local Interstellar Cloud's potential effects on Earth are greatly diminished by the solar wind and the Sun's magnetic field.
A change in the density of the near interstellar medium would shift the heliopause, but it would require a massive increase in density to move it from where the Voyager probes are now to somewhere close to the inner solar system where it could have a noticeable impact.
Due to stochastic nature of interstellar magnetic fields, cosmic rays, trajectory of which are bent by those, are practically observed from all directions, so even if solar system distorts its own magnetic field this will have almost no effect on vosmic rays flux. Magnetic field is not a shield, for the charged particles it is rather a lens which converges or diverges their trajectories.
Thanks for bringing this to our attention. "The G-Cloud contains the stars Alpha Centauri (a triple star system that includes Proxima Centauri) and Altair (and possibly others)" [0]
One of the best knock-on effects of these kinds of missions is that they provide the rare chance for news outlets to feel like they can report on something optimistic, hopeful, and positive for a change.
GenZ: Your parents are fucked up because they were kids in the 1980's. Today we worry about fucking up the environment so bad that all humans and higher mammals die out. In 1985 we were worried about sterilizing the entire planet with nuclear fallout.
If you think things are dire now, search Spotify for 70's, 80's, and 90's songs about how the world was going to end. Maybe every crisis is a little worse than the last, but they aren't out of the blue transitions from an idyllic age. That's just a bunch of pastoralism from older people who have suppressed a bunch of memories (memories that still affect their behavior in various situations).
Worrying is a rite of passage. You don't steward something until you realize it needs stewardship, and that it's soon going to be your turn to contribute. That epiphany can be traumatizing.
One probably coincidental thing is that the move to margarine and other more "sustainable" foods happened roughly in the same period as books and thoughts like "the limits to growth" came about.
The issue Is that for every single topic, there’s a cadre of crazies who deny that it is true or that it was ever an issue or claim that it’s made up or claim some conspiracy theory or yada yada.
The refuse of the media to actually shoot those people down means if they can’t actually report on anything.
> The Heartland Institute is an American conservative and libertarian public policy think tank known for its rejection of both the scientific consensus on climate change and the negative health impacts of smoking. Founded in 1984, it worked with tobacco company Philip Morris throughout the 1990s to attempt to discredit the health risks of secondhand smoke and lobby against smoking bans. Since the 2000s, the Heartland Institute has been a leading promoter of climate change denial.
“There is 2.24 million more square kilometers of forestland than 35 years ago”
How can this be true when our rate of deforestation is accelerating? The state of deforestation is nothing to celebrate, it’s horrific as far as I understand it.
“By most metrics we’re better off than the 90’s”
Except for economic metrics and people’s material well being??
According to this link the rate of deforestation is decreasing. But still, they say there is less forest now than there was in 1990.
"Since 1990, it is estimated that 420 million hectares of forest have been lost through conversion to other land uses, although the rate of deforestation has decreased over the past three decades.
Between 2015 and 2020, the rate of deforestation was estimated at 10 million hectares per year, down from 16 million hectares per year in the 1990s. The area of primary forest worldwide has decreased by over 80 million hectares since 1990."
Based on our current understanding of fungally dominated soils, restoring temperate forests will do far more per acre for atmospheric carbon levels than restoring the same acreage of tropical rainforest.
Which we also need to do soon because the longer you wait, the wider the band around the Tropics where fungally dominated ecosystems cannot thrive.
Not that we shouldn't have people working to slow tropical deforestation, but we can't and shouldn't put all our eggs in that basket.
Actually I just didn't share data because I forgot the name of the author who has best spoken to this critique, but I dug him up and it's Jason Hickel. He responded directly to Steven Pinker's rosy optimism about the world, in particular pointing out that our bar for what is extreme poverty is a made up number that is too low. If you use a more reasonable measure for extreme poverty, the situation looks a little different. It has improved in some areas and expanded in others. Notably, people like Pinker use their argument to say basically that capitalism is good. But Hickel points out that most of the gains were in China, where the economic system that led to all this growth was a very mixed system of capitalism combined with heavy state control. So under no circumstances can we conclude that free market capitalism is the main driver of reductions in extreme poverty.
India, Indonesia, Vietnam and other have also seen massive reduction in extreme poverty after adapting a capitalistic market system. All of them are different socially and politically but the free market impact is real.
Replying to myself since I can no longer edit, but with so many questions I finally dug up the author who I was trying to think of as a source to go against this kind of rosy picture of the status quo. It's Jason Hickel and he has written a critique of Steven Pinker's optimism.
Where Pinker looks at some arbitrarily defined numbers to decide that extreme poverty has gone down, and capitalism is the reason, Hickel criticizes those poverty numbers for being artificially low due to a poor selection of the poverty line, and points out that most of the reduction in poverty happened in china, where the system Steven Pinker argues for is not being used.
Finally anyone who is paying attention to the economics of people in just the USA for example must know that real wages in the USA have been stagnant for the average person since 1980, while living costs continue to rise. So the average person is NOT better off than they were in the 1990's, they are actually worse off.
People like Bill Gates LOVE Steve Pinker because Pinker provides an excuse to say the status quo is fine and everything is great. But in reality time is not a linear path towards nirvana, and real people are currently stuck working Uber and Door Dash to try to survive while in the 1990's they could have had a steady job. I'm struck by this notion that in the 1990's the janitorial staff at Apple were Apple employees who got treated with respect, but now they are contractors working for a company Apple has hired. So things are great for the engineers at Apple but in the 90's success for those people also meant success for the janitors. But we have managed to break that off so those people no longer get to see the gains that others see. We are stratifying the world more.
One can add "future oriented" to that. Seems like the only visions for the future in vogue these days involve harming crap tons of people for the sake of past imagery.
There is a detailed Mission Concept Report PDF linked on the probe's website: https://interstellarprobe.jhuapl.edu. It looks like they're targeting being functional at 400 AU, though it will take 50 years to get there.
Fun networking measurement: they describe the antenna bandwidth as ~150 Mbit/week at 400 AU.
I think we should be trying to do this kind of thing, but...
it does make you wonder whether in 30 years, we'll have the infrastructure (fusion, much larger LEO refueling capacity, etc) to put it there in 10 years instead.
5x faster is a spectacular improvement, the launch systems we have today are not much more capable than the ones we had 30 years ago. I don’t see any reason they will be all that much better again in 30 years, even with something like Starship.
The problem is the rocket equation is brutal. The more propulsion system you add to increase the speed, the more of it you have to accelerate up to the original speed before you start getting any improvement. We do have some nice advances like hall thrusters, but they don’t actually help much for heavy duty payloads like this, and there are no huge multi-order of magnitude engine efficiency breakthroughs on the horizon.
Are these probes micro-accelerating the whole time with ion engines? You'd need 4 times the average velocity to cover the same distance*, which means 8 times the final velocity, which means accelerating from 0 to 8 over 10 years instead of 0 to 1 over 40 years. That means 32x more acceleration over the whole period. No: we won't have that technology in 30 years, nor in 100 years.
Maybe, maybe, maybe if you were able to refuel in orbit and strapped a ginormous multi-stage chemical rocket onto the thing in orbit. Maybe. But we're not going to be doing that in 30 years either.
* Higher velocities can mean shorter distances though, because your trajectory is less warped by the curvature of space. The biggest time saver would be avoiding time-consuming gravity assists, if there are any (I assume there are, but I didn't download the 500-page PDF).
I would hope we actively plan for much cheaper launches with Starship coming online. It seems like we can do many more projects, at lower cost and higher risk than before, because launch costs are low.
Instead of $1-$10B projects focus on things <$100M. Or at least focus on platforms to enable cheap probes without so much customization. It should be possible to pull off things like this soon without even government funding. Just buy a stock probe with some modifications and launch it cheaply in a direction you want.
Probes could be mass produced and then shipped to space once a year with a Starship launch. A thousand probes per year would be great. Most of them could use the same gravity assist routes and then take off from there in slightly different angles. Space is huge.
Any billionaire looking for being remembered for millennia?
> Instead of $1-$10B projects focus on things <$100M
The entire mission budget for ISRO's Mars Orbiter Mission/Mangalyaan probe was a mere US$74 million. Modi famously boasted that this was cheaper than the budget of the Hollywood film, Gravity (2014).
There are countries in the world besides the US which can reliably and very cheaply place satellites in orbit. India has been a launch provider for many other countries in the region (Singapore, Indonesia, Thailand, Malaysia, etc) which do not have their own launch capability, and their PSLV/GSLV rockets are workhorses, having launched hundreds of satellites for customers worldwide.
The problem with that is the launch costs are a small fraction of the total cost of these big missions. A launch on an Ariane 5 costs $177m, that’s a small slice of the total $10bn cost of the JWST. Starship will really shine for cheap heavy payloads.
A huge portion of the JWST cost was specially designing it to fold and unfold in a certain way due to the size of the rocket and the size of the spacecraft. First, smaller probes wouldn't have that restraint, and second, SpaceX's upcoming bigger launch vehicle won't have that restraint for JWST-sized craft.
> I would hope we actively plan for much cheaper launches with Starship coming online.
(disclaimer: I'm a SpaceX fan) Savings that was supposed to be generated by rocket reuse with Falcon 9 haven't trickled down to clients, if I understand situation correctly. What makes everyone think that Starship will bring cheap kg-to-orbit era?
While I'm all for more of these space missions, my personal #1 priority is return missions to Uranus and Neptune in the next window for favorable planetary alignment to get there in reasonable time. That's the same window as this (mid-2030s). It would mean such probes wouldn't reach their targets until the mid-2040s.
Time is actually rapidly running out to launch in this window because such a mission can easily take a decade to plan, design and build. Missions to Mars might be a few hundred million but Cassini or Juno style missions are in the billions. Getting such a mission funded is a far more onerous task. It's generally a flagship joint mission for ESA and NASA and then adds all the politics of that (eg using Ariana launch vehicles to mollify Europeans).
We've only been to the ice giants once and it was the Voyager missions. I hope we go again in my lifetime.
Not sure I like the "Voyager on steroids" - I strongly associate Voyager with the Grand Tour of Jupiter, Saturn, Uranus and Neptune. Seeing those pictures come back when I was a child made me do astrophysics at university. "Mission would probe the region beyond our Solar system" is fine though.
Yep! The only people I've ever known who were (literally) "on steroids" were uniformly and without exception psychopathic jerks. It's a stupid epithet, frequently used to describe the exact opposite of the sentiment it tries so pathetically to convey. Phrase ought to be retired.
More on topic: I'd love to see a mission or more focussed on exploring interstellar regions. I'll bet there's a whole lot more we'll learn there, even though I'll be long dead by the time it rolls around.
> I'd love to see a mission or more focussed on exploring interstellar regions.
Yes. I did like the article, eventually, buried in the details, was "twice the speed of Voyager", and "can't gravity assist past the Sun, no real saving and might go wrong".
Steroids are used for a lot of medically important uses. I used steroidal inhalers to heal my throat/lungs after a flu-like something several years ago. Worked wonders.
Yes, of course you're right, and I was in error thinking only of the people who use steroids for non-medical purposes, and forgetting that there are many legitimate applications. My bad, and I apologise for that oversight.
What sort of instrumentation would be onboard? The last mission destined to leave our solar system was New Horizons[0] and its equipment was designed in the early/mid-2000s with the express goal of imaging the outer planets. Both Voyager probes have some instrumentation still sending data back to Earth[1] as well, though current projections estimate we may only be receiving data from them for until the end of the decade. Sending a probe out that only improves on a few areas such as ionized plasma detection and gas chromatography to determine what elements are in the heliosphere seem to arbitrary improvements on a short timeframe; but these are systems designed with a 50+ year lifespan. The 500 page report published by NASA[2] for a future insterstellar probe is a bit much for a layperson to understand, but such a program can also be done over a longer timeframe to justify its continued funding.
It's been over 40 years since we last launched a probe with the express purpose of exploring interstellar space, and technology has improved to the point of enabling these missions to be multi-generational by planning further launches to create a networked constellation. When I was a kid seeing the 'Pale Blue Dot' image in the book Cosmos, it gave a perspective of looking at humanity's achievements on a cosmic timescale instead rather than only the human timescale, and I think setting long-term goals of exploring our universe are held by everyone regardless of nationality. Delivering tangible results to the public like JWST's fantastic images and the 'Pale Blue Dot' photo are arguably just as important as the scientific data gathered.
I had a weird dream about a secret Voyager probe recently, the Voyager III, and wrote a short story about it, if anyone’s interested: https://f52.charlieharrington.com/stories/voyager-3/ It’s fairly “Contact” by Carl Sagan inspired.
Maybe someone with more knowledge/experience can chime in here since I'm fairly ignorant of the Voyager program - was a bit before my time.
From what I understand the voyager probe(s) did some pretty crazy gravity assists to launch themselves out of the solar system - flying close enough to different planets in our solar system to build up great speed.
Could we not throw a giant solar sail onto a probe and send it out? I guess the acceleration would be smaller and smaller when you get further and further out with the sun being further away, but at least you'd still be gaining velocity, right?
I don't have the time and mental resources to browse through these research papers all the time but knowing that what I'm asking is actually in the paper, maybe I'll give it a browse.
Heh it was that as “Voyager on Asteroids” I was intrigued!
But this sounds even more interesting getting modern instruments aboard a new generation of voyagers to probe the heliosphere and beyond with better instruments.
Slight OT, but I wish “on steroids” wasn’t used in serious publications to refer to improvements and overall positive evolutions. I know it’s colloquially accepted, but we also wouldn’t express someone being very focused as “being on Adderall”, or a very creative idea as being “on shrooms” in a scientific publication.
> we also wouldn’t express someone being very focused as “being on Adderall”, or a very creative idea as being “on shrooms” in a scientific publication.
We don't because nobody does, and many people might not know what you mean.
The voyager mission was originally planned to be with a no-expense-spared Cadillac of a spacecraft, however they ended up going with the bargain bin absolute cheapest possible option.
The same thing that happened to Khalessi (played by Emilia Clarke) and her dragons. Which is to say, nothing happened to them at all, because they are all fictional.
> Sometime in the next 2000 years, the Sun is expected to leave a local cloud of gas and dust. After that, it may enter the G cloud. If it is denser, it would squash the protective magnetic bubble of the heliosphere, potentially exposing the Solar System to a barrage of cosmic rays.
Mostly surprised that I hadn't heard more about this. 2000 years is practically tomorrow in cosmological time!
A little more here:
https://en.wikipedia.org/wiki/Local_Interstellar_Cloud