A 1980s space telescope may have seen planet nine | Hacker News Reader

A 1980s space telescope may have seen planet nine

gizmodo.com

172 pointsstarwind128 comments

Mike Brown recently wrote a summary of his and Konstantin Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper belt objects (KBOs) whose orbits appear skewed by the invisible gravity of a possible Planet Nine, accounting for observation bias, and running a ton of simulations and MCMC, they concluded: if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth masses and a perihelion (closest approach to the Sun) of 300 (+85/-60) AU. The median distance at aphelion is around 500 AU. Those are not small error bars, but they do constrain the search, and this proposed finding of 225±15 AU and a mass of 3-5 ME could just ~barely~ fit.

The summary: https://findplanetnine.blogspot.com/2021/08/the-orbit-of-pla...

We’ve been covering this search in Orbital Index (https://orbitalindex.com), subscribe if you want updates.

According to Mike Brown, the infrared sighting from Rowan-Robinson is in a different location in the sky than was predicted by the aforementioned Planet Nine hypothesis.

In other words, if this infrared sighting is real it would be a different Planet Nine!

https://twitter.com/plutokiller/status/1458038427090178052

Planet 9 3/4?

Isn’t that where you board Galaxy Express 999?

Harry Potter and the Conspirator's Planet.

So if it turns out that both this object and the hypothesized Planet 9 exist, which one is further out and gets to be Planet X?

I really like how that worked out that X would be 10 instead of placeholder_name, and I do hope that at least our grandchildren will see such a discovery.

I’m just mad we’re losing out on “Planet X”. When I was a kid Pluto was a planet so the new one was X (10) and it was cool. Now this new planet is just going to be planet 9 again… totally lame.

Oh man this was me! I 100% agreed until I saw relative size of Pluto[0].

Definitely seems unfair to call it a planet when there's a number of Kuiper belt objects that are larger[1](?) or pretty much the same size.

[0] https://www.quora.com/Why-is-Pluto-so-different-from-the-oth...

[1] https://www.universetoday.com/118118/it-looks-like-these-are...

Planetary scientists tend to consider Pluto, and those large Kuiper Belt Objects, to be “planets.” It’s just certain astronomers, who don’t usually study planets, who voted to remove them from planethood. https://www.ucf.edu/news/pluto-planet-research/?amp

Pluto is an impressive planetary system with a bunch of Moons and active geology. I’m gonna call it a planet.

Also kind of funny, but this guy who is obsessed with finding “Planet 9” (which doesn’t seem to exist) is also the one who tried and succeeded at demoting Pluto.

Can't we just add Pluto and Charon together and say "by your ~powers~ masses combined, I am ~Captain~ the ninth Planet!"

Pluto is closer in size to Earth than Earth is to Jupiter, but we lump them both into the same category.

There was a real concern that we were going to find thousands of Pluto sized objects in the kuiper belt, and that when we observed them up close they were just going to look like big comets. Instead it turns out there are only a handful and they are fascinating worlds with many similarities to other planets.

But it's from outer space.

The .plan thread is four up from here.

I think Planet IX has a better ring to it.

But I also enjoyed reading the Dune series by Frank Herbert.

Many machines on IX.

Better than those on Richese.

Uncle Malky deserved better.

Maybe there's a second one!

Planet 9 II

Perhaps a dumb question, but if we have some idea of where it was and its probable orbit back then, then why don’t we have some idea of where it is now?

Not at all a dumb question! The argument goes that we haven't had powerful-enough telescopes (or enough dedicated observing time) to image it.

Not everyone buys this; some people think it does not exist, and the perturbed orbits of Kuiper Belt objects are just a random fluke.

"Some idea" is the problem. Basically at the orbit we think it's at, even at the relatively large size they're expecting, it would be a tiny, tiny black dot. It's the proverbial needle in a haystack, knowing which haystack it's in is only the beginning.

I wonder how far would it be from New Horizons.

The scientist that found this potential planet in the old data did calculate the location where the planet should be and provided it in his article.

I'm sure there will be follow up studies and some telescopes will be pointing.

Yes we should.

Also, Mike Brown's free 'The Science of the Solar System' course on Coursera is excellent. Highly recommended. https://www.coursera.org/learn/solar-system

Excellent suggestion!

Love the newsletter by the way. It's the only one out of dozens I receive that I actually read every time.

I can recommend anyone that has an interest in anything space related to give it a read.

Thank you! I’m glad you’re enjoying it.

Relevant part:

For the recent work, [Michael] Rowan-Robinson redid his search from nearly 40 years ago and found three points in the data from late summer 1983 that indicate some object moving across the sky. The data sources sit low on the galactic plane, though, meaning that the satellite was taking the data through plenty of dusty, cloudy material that can emit infrared light. In other words, the work is something of a long shot. And Rowan-Robinson is well aware of that. “Given the poor quality of the IRAS detections, at the very limit of the survey, and in a very difficult part of the sky for far infrared detections, the probability of the candidate being real is not overwhelming,” he wrote in his paper.

Isn’t that bigger news than it sounds at first? Part of the problem of finding planet nine must be knowing where it currently is on its orbit. A few possible observations should help to narrow down the space in which to look for it by a lot (rather: would make it almost clear where it currently is). Maybe JWST could be of help with testing the hypothesis that these early infrared observations of a moving object were of planet nine - once it has finally and savely launched and begun its operations?

Would have commented this same thing. It should be a matter of translating the coordinates into a search pattern to look at with JWST.

Every millisecond on JWST is booked years in advance already. Unless Planet 9 searchers turn up with some good guesses and not just a search pattern, other research with far more likelyhood of success has priority.

Finding it may be complicated if it is hiding behind a cloaking device.

Here's a youtube video by Anton Petrov describing the paper https://www.youtube.com/watch?v=ZSyAO4fGZOE

He's always quick on these, and always with quality videos.

Anyone with an interest in space who has not watched any of Anton's videos are seriously missing out.

Thats me! thanks for the input. Yt really puts you in a bubble unfortunately. Would be cool if one could "explore" different branches of it...

So say we all.

I watch all of his videos and it's always an interesting, learning experience.

His videos are unnecessarily long

The most vital information is presented and explained in the first 30 seconds of the video.

If this object did exist, wouldn't it be classified as a dwarf planet since, like Pluto, with a highly elliptical orbit it would be difficult to clear it of other Kuiper belt objects?

The sufficient-but-not-necessary conditions for identifying a planet are called into question as a workable definition once more.

We’ve duck-typed the solar system, I guess.

I hate to be the one to break the bad news to you, but... That's pretty much how all science works.

https://en.m.wikipedia.org/wiki/Species_concept

Categorization is a leaky abstraction. Use them when they're useful, and ignore them when they become more trouble than they're worth.

My favorite example of this is that trees aren’t really a phylogenetic group all their own. They’re just plants and plants can become tall and woody with a few genetic tweaks. You can’t trace trees to a common ancestor because the ancestors of many types of trees are just ordinary plants.

https://eukaryotewritesblog.com/2021/05/02/theres-no-such-th...

Same goes for fish, which I just read in the excellent book "Why Fish Don't Exist" by Lulu Miller. An example being that a lungfish has more attributes similar to a cow than to a salmon.

This is an example I also find helpful when dealing with people who insist that "there are only two genders" ("because science"). Even species is a leaky abstraction, let alone sex, gender and sexual attraction. You can argue for a strict gender binary normatively (and we can disagree on that), but even if you try to conflate gender and sex it's still scientifically illiterate to insist that there is a strict binary (although for sex at least humans are bimodal).

Leaky abstractions can still be useful but you have to be aware that they're just abstractions and still understand that reality is messy and complicated or you'll end up legislating the value pi.

You make the point beautifully, and I really appreciate how you bring home the consequences of flawed thinking in our politics.

At risk of maybe going too far on a tangent, I understand this idea and the species example is a good one.

The planets are different because they were first defined as mystical and cultural concepts, before they could be understood as scientific ones. There are plenty of people who still think about the planets as cultural concepts rather than scientific ones. (What is a Jupiter? It’s a thing in space that our culture has named “Jupiter.”) I think we should define the planets the way co-star does. By listing them:

DATA PLANET = MERCURY | MARS | ETC

Scientists can have their own definitions of things, but they will face resistance if they try to dictate culture through their definitions.

https://www.costarastrology.com/why-haskell/

I'm pretty sure animal and plant species also existed as cultural and mystical concepts, long before science was a thing. All of your analysis can be applied equally well to species, as well as planets... Or the four seasons (winter, spring, summer, autumn) or the five Oceans, or the seven Continents.

They're all simply human attempts to impose neat category boundaries across a continuum of natural phenomena that are definitely not neat.

Categories can be useful, but they often lead to pointless arguments by lay people (a la Pluto's relegation) when we start to fetishize a human-created category structure as an essential expression of underlying reality. It's just plain old human narcissism.

I think this boils down to journalists trying to bait outrage by implying that scientific definitions should dictate cultural ones (tomato may be a fruit biologically speaking but if you put it in a fruit salad nobody will like you).

Pluto is a "planet" in the same way the sun is "not a star". If you tell someone to draw some stars you'll be confused if they just draw a few massive orbs of fire rather than some bright dots.

Before publishers discovered outrage bait as a way to sell ads, "actually Pluto is a dwarf planet not a planet" would have been an irrelevant nerdy factoid but now it's presented as a cultural issue everyone needs to have an opinion on.

So I propose just giving scientists migraines instead and discussing whether the sun and moon should be considered planets or stars.

You have good points here for scientific understanding vs cultural in general. I wasn’t specific enough.

The planets formed as cultural concepts in the sense that they were absolutely divorced from tangible experience other than in their role as mere “wandering stars,” allowing them to exist as pure symbolic archetypes. The idea of Mars bringing war has little to do with the fact that it and related objects have cleared their neighborhoods.

There’s a distinction here between the planets, which are the symbols that can be enumerated, and a planet, which is what the categorization problem for scientists involves.

I think the criteria are more along the lines of "gravitationally dominate its orbit", which due to the perturbations of KBOs this object would do. Otherwise, basically all planets would be demoted (e.g. Neptune has not cleared its orbit because Pluto is there, Jupiter hasn't because of the Trojans, etc.)

I asked Mike Brown this on twitter earlier this year and he said it will have cleared out it's orbit so that won't be a problem.

" definitely clears! "

https://twitter.com/plutokiller/status/1433802812945625095

An object with multiple Earth masses could hardly be classified as a dwarf planet.

It very well could. Defining a planet as major or dwarf goes by its ability or inability to "clear the neighborhood", to control or remove objects of smaller mass in its orbital area.

225 AU is a long way, and the volume of space to clear goes up quadratically with distance; this object would have 50,000 times more space to clear than does Earth. The orbital period also goes up with distance [edit, reply is right that it's the 3/2th power], so so does the time between interactions with any particular object.

Multiply those together and you would have an object more than cubically (3.5th power) less effective than Earth at clearing its neighborhood over time, such that it may not have happened in the lifetime of the solar system.

>ability or inability to "clear the neighborhood",

who said it has finished the job? has the correct paper work be filed? according to the permits in the galactic construction offices, the work is not scheduled for completion for a few hundred more millennia.

> The orbital period also goes up quadratically with distance

By Kepler's Third Law, isn't it proportional to the square root of the cube (3/2th power) of the distance?

It's on a plane. Circumference goes up lineary

It's undefined whether "clearing the neighborhood" involves the spheroid at that distance or just the plane. It hasn't come up, since all eight known major planets do satisfy the three-dimensional criterion. We'd probably revise or clarify the definition if we discovered an object that cleared its plane but not its volume.

"A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite."

According the the wrong-headed AIU definition. So, yes, _Jupiter_ could be a dwarf planet, if it hasn't cleared it's orbital neighborhood for some reason.

https://en.wikipedia.org/wiki/Clearing_the_neighbourhood

Weird definition since it prevents deciding if an exoplanet is a planet or a dwarf planet.

It smells like a compromise proxy measure for: orbital stability, in a reasonably circular orbit, plus rule out Pluto.

Maybe there is some deep reason for using that measure, but it is not obvious.

As far as I can tell, many planetary scientists aren't particularly fond of the definition either. I believe the initial plan that the IAU had after the discovery of Eris was to classify dwarf planets as planets, but some of the members didn't like the idea that our solar system would suddenly get a lot more planets, so pushed for the current awkward and ill-defined IAU definition.

Though there are a lot of people that present the IAU definition as if it were simply the will of "science," if you look at the 2006 debate about it amongst scientists, it was actually fairly contentious.

"Scientists who search for Planet Nine estimate that its mass is several times bigger than Earth’s... "

So no. It won't be a dwarf planet.

The Vera Rubin Observatory in Chile is under construction and will image the entire sky every week using the largest digital camera ever built.

Hopefully searches along the plane of the ecliptic won't be sabotaged by Starlink or other LEO satellites.

Large facilities were never threatened by Starlink as they easily compensate the issue was amateur's and very small facilities.

Not true at all, totally depends on the type of observation campaign. Plenty of big observatory projects are negatively impacted by the eternal march of "progress."

> "progress."

Do you really think Starlink is not a step forward? It is realistically the only path to get the whole world access to the internet.

If by “whole world” you mean the wilderness, then sure! Otherwise we’ve had no issues laying cables to any place people live, so long as it makes sense to do so.

If by "makes sense" you mean to ISP shareholders - for ISPs to take federal USF funds and never, ever deliver on the required upgrades or expansions (eg:Frontier@WV,Verizon@PA), due to regulatory capture.

I’m not going to be the one to defend the actions of a group of my least favorite companies in America, but you hit on the main point that stands up globally: where it is profitable to lay cables down. So yes, where it makes sense to shareholders.

That’s not to discount Starlink, it is a comparative advantage to be able to cover the wilderness, but that and not being an existing ISP people have had lots of experience with are its distinguishing features.

>get the whole world access to the internet

Starlink is yet another printing press, a tool to control information. It can be wielded for good and bad, just like any other technology, and it will be for both. Has the internet made the world happier? Better? By whose definition? It's certainly made many wealthier, but it's also destabilized countries, facilitated genocide, spread misinformation like nothing before. Just like any other communications technology.

The worship of tech as savior in silicon valley and its followers never ceases to amaze me. Tech is inert; has no intrinsic moral value at all.

I really hope it's a bowling-ball-sized black hole so we can start slingshotting rockets off into deep space.

  Radius of bowling ball: 12 cm [1]  
  Mass of black hole with radius 10cm: 0.00004062 Sun Mass [2]  
  0.00004062 Sun Mass in kilograms: 8.124E+25 [3]

That's significantly more than 10 times the mass of the Earth. Even a grape-sized black hole would be more massive than Earth. Highly unlikely to be such a massive object, hithertofore undetected. The most massive object expected would be smaller than the Moon, which for a black hole would be the size of a human ovum.

  [1] https://hypertextbook.com/facts/2009/MarwaElfar.shtml
  [2] https://www.omnicalculator.com/physics/schwarzschild-radius
  [3] https://www.unitconverters.net/weight-and-mass/sun-s-mass-to-kilogram.htm

Or build a Dyson-sphere like machine around to capture its energy and power humanity for ages

Honest question:

Can’t the oddity of planet orbits also be explained by a sun in motion causing the orbits to be a little dragged shape? The direction of drag is probably the ghost planet 9?

Dragged through what? It's not like the interstellar medium has friction.

In addition, our entire solar system condensed out of the same primordial soup, with the same sort of motion about the galaxy. Just as our sun is in motion about the galaxy, the planets are in essentially the same motion.

you're asking a good question, that I'm not really qualified to answer, but in short I think no, that's not the explanation. what you're talking about is a general relativistic phenomenon: just as it takes a few minutes for the sun's light to reach earth, it takes an equal amount of time for the sun's gravity to get here, and by then the sun has moved on. However, I don't think that is responsible for these orbits.

That subtitle was in no way accidental.

I might physically appear be middle-aged but the 12-year-old in me snickered loudly.

Should have been Neptune right.

Can anyone explain how we’re able to detect dozens of exoplanets (Wiki says we’re up to 4864!), but not be able to detect every large boulder around our own star?

There are two main ways we detect exoplanets. The primary way that I believe accounts for the vast majority of planets we have detected is the transit method. Basically we watch the light from a star very closely and look for a dip in the amount of light coming from it as a planet transits in between us and the star. This of course depends on the planet to pass directly between us and the star, and that means that its ecliptic plane has to be directly edge on with us. The second method is that we are able to detect minor wobbles in a star that infers that there is a planet sized object that is perturbing the star. I believe this is only able to detect Jupiter sized objects up to brown dwarves or other stars though, and even that depends on the distance to the star, and I believe only when the planet orbits at a relatively close distance (I believe closer than the kuiper belt)

The problem in both cases as it relates to planet 9 is that you arent detecting the planet as much as its effects. If you take any planet that far away from a star and youre trying to detect either the very little bit of light that it might be reflecting or its infrared heat signature if youre lucky, but both are incredibly dim.

If that is the threshold for discovering exoplanets, haven't we already found Planet Nine since we definetly have detected the planet's effects?

Good objection actually. We could say that we found exoplanets visually, can determine its mass and size and therefore its density and make careful prediction about its characteristics from that, which is probably nothing more than an educated guess.

Here we just found its gravitational effect.

Most of the exoplanets that we detect today are very large and orbit very close to their star, and happen to pass between us and the star during their orbit. This is why they are often referred to as "hot jupiters". We see them by seeing the dimming effect on the star as they transit between us, and we need to see a few tramsits to be sure that we are looking at an orbiting object and what orbital period it has.

There are just a mind-boggling number of stars out there, making 5,000 hot jupiters a small number.

The way we detect things in our own solar system is basically to take several images of the same patch of sky and look for things that moved. Objects that far out have a slow apparent motion and require repited observations days apart. We have a limited amount of telescopes that are sensitive enough and time on them are very competitive. But we have new telescopes on the way and on the next few years there will likely be many more confirmed objects on the outer solar system.

Am I the only one who's mildly annoyed by the 9th planet being referred to as Planet X?

Seems like "Planet Ix" (same pronunciation!) would have been a better name?

The designation was not a Roman numeral but Lowell's designation for "unknown". It would have been the 9th planet if discovered, at the time Lowell coined it, anyway

Pluto was still considered a planet in the eighties, so at that point an additional planet (if discovered) would have been the 10th planet.

Pluto was discovered in 1930. The term was coined decades before that.

I think it's a semi-deliberate pun. It was Planet 10 when people started looking for it. Then it would be "Planet 9", which is confusing. So they called it then "Planet X" as in 'ex', nerdily harking back to the good old days when Pluto was still a planet.

The theory was proposed and it was anointed 'Planet X' when Pluto was the 9th planet, with X as the Roman numeral for 10. Now it's a play on 'X' being something unknown. Nothing to get annoyed about.

I just bent space from Ix. Many new machines there.

If they don't name it Yuggoth I will be disappointed.

https://lovecraft.fandom.com/wiki/Yuggoth

There’s all kinds of silly names they could borrow from stories hypothesizing its existence. Nemesis, Nibiru, Vulcan, and Planet X, just for starters. But in all likelihood it will end up as something much more anodyne.

Sure, I'm OK with naming it Le Creuset.

Oh, you meant anodyne ....

I think the IAU will only accept names from Mythology.

Here you go: https://www.iau.org/public/themes/naming/ - in short, it can't just be named by snapping fingers obviously as there's a review and approval process.

They extended naming conventions to other cultures already - IIRC Roman and Greek sources were "drying off"

There's a region on Pluto provisionally named after Cthulhu, citing Lovecraft as "an underworld mythology". If the IAU accepts the name, it would make this possible too.

I've got a silly question, could there be some long term effects of an object that had been there?

For instance, could there be some kind of elasticity or residue, something like radiation that could cause a dissipated gravitational like effect long after the thing has moved on or otherwise "disappeared" in some way?

In this very likely wrong model maybe the thing causing the effect visited hundreds of years ago and was just passing through and so it's no longer directly observable...

I only lovecraft where here to witness this and possibly write even more stories about yuggoth and the eldritch things that might lurk on it

Cool. So in ten years time, they'll tell us again that it was actually a 'gas giant' not a 9th planet

If Planet 9 contains rare earth metals, mining and manufacturing facilities could be built there. This should help alleviate the chip shortage.

Rare earths are neither particularly rare, nor particularly likely to be unusually abundant on a Planet 9.

However!

A Mars or Earth-sized planet sufficiently far out in the solar system might be sufficiently cool to be able to retain helium in its atmosphere, without being a gas giant planet. If so, it might conceivably be the best place in the solar system to obtain 3He, an isotope that has considerable attractiveness for use in fusion reactors. A D-3He fusion rocket might even provide a nice way of getting out there and back in a reasonable time.

I don't see how the "attractiveness" of helium-3 is anything non-zero. If you can't even fuse deuterium with tritium, which is the easiest thing there is, helium-3 fusion goes out of the window.

DT is certainly easier to fuse, but it presents very difficult, IMO likely intractable engineering problems. D3He would finesse those problems (neutrons, material damage, tritium breeding), and potentially enable direct conversion of fusion energy to electrical energy (or, perhaps, more volumetrically efficient transfer of thermal energy to coolant). So IF the physics can be made to work, D3He could end up being more practical.

The company to watch on this is Helion, and perhaps Princeton Satellite Systems.

https://www.helionenergy.com/

https://vimeo.com/553784697

The moon already has a whole lot of helium 3 that'd be economically viable right now, if there were a use for it yet.

The moon has 3He, at a concentration of maybe 10ppb, in regolith the heating of which would use more energy than the released 3He would yield in fusion.

Helium at cosmic isotope ratios is 120ppm 3He. So if there were a planet out there with an atmosphere of this helium, extracting the 3He would be much easier (just compress, liquefy and separate, which you'd have to do with lunar helium anyway.)

The technology and infrastructure needed to reach Planet 9, build a mining outpost, then transport everything back at a profitable cost is likely decades if not centuries away. That’s not counting the fact that Planet 9 is so far away that getting there with current technology is a lengthy affair in itself (the New Horizons probe wouldn’t even be halfway to a theoretical Planet 9, and it’s been flying for over 15 years!)

Not saying I don’t want this to happen - I would love nothing more than to have humanity push out into the solar system, but recycling or scavenging is infinitely more of an realistic option.

> likely decades if not centuries away

The fastest man-made object ever launched was the New Horizons spacecraft. Headed on an intercept course for Pluto 30 AUs away, it took 9.5 years to get there. And that's without slowing down; if you actually wanted to land on Pluto you would need to spend even more time actually slowing down. The object in the OP is 225 AU away (which is dramatically closer than prior estimates of the distance of Planet 9 (300 AU)). All this means that, even moving as fast as we have ever launched a spacecraft, it would take at least 70 years for a probe to reach Planet 9, even without taking time to slow down. A probe launched today would return with its cargo no sooner than 2160. That's probably never going to be economical, even with future improvements to spacecraft propulsion (moving faster just means you need more and more fuel to slow down, at which point you are beholden to the tyranny of the rocket fuel equation).

It's easy to forget the scales here. We're used to Pluto being our reference point for "far edge of the solar system", and it's easy to conclude that Planet 9 is about as far as Pluto, but it's so much farther. Voyager 1 is a bit more than halfway that far.

I dont mean to take away anything from your post - but wanted to mention that the parker solar probe has now beat new horizons for fastest man made object (if you don’t count the manhole cover :) )

Indeed, but the Parker Solar Probe is cheating, since it's going so fast because it's literally plummeting into the sun--the exact opposite direction of a deep space probe. :)

Is this performance art? Do some napkin math on the quantities of fuel alone required to do this.

We have plenty of rare earths here on our homeworld. If we run out (which we won't), we'll scavenge before we build the trillions of dollars of infrastructure necessary to mine the solar system.

Or we could, you know, build mining and manufacturing facilities on a planet that's, say a couple of AU away, instead of a couple of hundred AU. There's reasons we've done neither.

Rare Earth metals aren't actually that rare. We even have a lot of big mines that are closed right now because its not profitable enough yet and many other sites enrirely undeveloped.

You're joke (it's a joke, right?) is apparently humor that's a little too dry to be detected as such.

Planet nine... why not simply consider it as something in the same level of conspiracy theories until better evidence arrives?

I grew up being told there were 9 planets, then I started being told there were actually 8 planets, now I'm being told again that there are really 9 planets. Wish the astronomers would just make up their minds.

If whomever was responsible for demoting Pluto from being planet nine is reading this, you’re a dweeb.

I'm not that guy, but I took a semester of astrophysics so I'm practically an expert.

If you drop the "has cleared its orbit of most obstacles" criterion, you have to admit something like 105 new planets. Pluto will always have a special place in our hearts, but it had to be done.

That’s Mike Brown! His book “How I Killed Pluto and Why It Had It Coming” is a great scientific memoir, and very funny too.

https://www.penguinrandomhouse.com/books/19851/how-i-killed-...

Lol, Hubble is a "1980s space telescope". It was launched in April 1990....

Amazing how they could design and built such a device in four months...

I don't think you read my comment correctly...

The article is referring to the Infrared Astronomical Satellite.

https://en.wikipedia.org/wiki/IRAS

I know, my point is that "80s space telescope" doesn't mean it's something super old that's not in use today...

Reply on news.ycombinator.com