Possible new dwarf planet found in our solar system
minorplanetcenter.net158 points by ddahlen 3 days ago
158 points by ddahlen 3 days ago
I found the preamble at the beginning of the announcement charmingly dated:
> The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements. They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. > > Prepared using the Tamkin Foundation Computer Network
Looking up the Tamkin Foundation Computer Network: https://www.minorplanetcenter.net/iau/Ack/TamkinFoundation.h...
> The OpenVMS cluster consists of nine single-CPU workstations and one four-CPU server. All the machines are running the extremely robust and secure OpenVMS operating system. The twelve Alpha-based machines are arranged as an OpenVMS Cluster, allowing all machines to share disk storage, execution and batch queues and other resources, as well as simplifying system management.
Assuming "Alpha-based machines" is referring to the DEC Alpha, these computers are ~30 years old. https://en.wikipedia.org/wiki/DEC_Alpha
Maybe not as old. I deployed a few racks of HP Alpha DS25s in 2007-2008 before they were replaced with Itanium based Blades (running OpenVMS 8.4). I do not miss working with OpenVMS one bit. It was rock stable (basically an on/off appliance) but the user experience left me wanting (coming from Linux).
I can see how they may be still stuck on Alphas because unless they can somehow simply recompile for x86-64 OpenVMS, it’s a complete rewrite from scratch.
Could they not get more juice out of a single, modern server? I get porting over to a new system and migrating is a huge time suck and a good enough reason not to do it if everything is working, just seems excessive for 14 cores.
> Could they not get more juice out of a single, modern server
They could probably get more performance out of one core on a modern phone, never mind a single modern server. But you see some really old systems in a lot of equipment, not because the porting costs are expensive, but the certification of proving the new system works the same is more than the operational cost of the legacy equipment.
I’ve heard of consultants who will virtualize systems like this in place using qemu emulation of CPUs like Alpha and Sparc and run it on a single server or in the cloud.
Sure, but the capital and one-time cost of acquiring and shifting to the modern server would be non-zero, and it would entail some risk. (While OpenVMS is maintained and runs on newer systems, that doesn't mean the software that matters on the existing cluster would run without modification.)
It probably would save operating costs, and probably over a reasonably short window, if it was done successfully, though.
> Could they not get more juice out of a single, modern server?
Maybe the software they use won’t easily run on a modern server.
You could ask them, but you might have to hook up your modem and try to call them. Maybe they have a BBS you could leave your question on.
The minor planet center is the clearing house of observations of objects in our solar system. They have announced a new dwarf planet today.
This object appears to be in a very eccentric orbit (0.948), and with an H magnitude of 3.55, so it is likely hundreds of km in diameter. Ceres for reference has a H magnitude of 3.33 (smaller H is bigger diameter).
If you want to know what H means: https://en.wikipedia.org/wiki/Absolute_magnitude#Solar_Syste...
If you want to view the orbit:
https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=2017%...
Thanks, it helps quite a bit to be able to visualize what they're talking about.
Out at 90 AU, and by the year 3000 is out at 500 AU, and that's still not anywhere near maximum distance. Looked like it was going to be 10,000+ years orbits or longer, and probably out at several 1000 AU at maximum.
Little skeptical it would even orbit normally with how heavily eccentric it is, and the extreme distance at maximum. Way... out beyond the heliopause / heliosheath / termination shock.
The fun part is the ~1700 AU aphelion is still not far enough out to be part of the Oort cloud. https://science.nasa.gov/solar-system/oort-cloud/facts/
Well, the preprint announcing the discovery describes its orbit as extending to "the inner Oort cloud" even though aphelion is 1630 au.
> and probably out at several 1000 AU at maximum.
The preprint announcing the discovery lists the semi-major axis as 838 au, so the major axis is 1676 au and aphelion is about 1630 au.
Does anyone know if this has its PE in alignment with the other Sedna type objects found?
I think there is a tendency for them to have their PE out to one side and the AP out to the other giving a fairly obvious pattern indicating another larger object is shepherding the others into their orbits.
> This object appears to be in a very eccentric orbit (0.948)
from [0]:
> Before its demotion from planet status in 2006, Pluto was considered to be the planet with the most eccentric orbit (e = 0.248). Other Trans-Neptunian objects have significant eccentricity, notably the dwarf planet Eris (0.44). Even further out, Sedna has an extremely-high eccentricity of 0.855 due to its estimated aphelion of 937 AU and perihelion of about 76 AU
> ...
> Comets have very different values of eccentricities. Periodic comets have eccentricities mostly between 0.2 and 0.7, but some of them have highly eccentric elliptical orbits with eccentricities just below 1; for example, Halley's Comet has a value of 0.967
so possibly an ignorant question, as someone who's interested in astronomy but doesn't follow it very closely - when this is categorized as a dwarf planet, does that include "it might be a comet" as a possibility? or have they already ruled it out as a possible comet through other observations?
0: https://en.wikipedia.org/wiki/Orbital_eccentricity#Examples
Dwarf planet versus comet/asteroid hinges on mass, basically its "enough mass to be roughly round" (technically it's called "hydrostatic equilibrium").
Back from the 1810's to the 1870's or so, most people considered Ceres, Vesta, and things like that to be planets- they were bodies that wandered around the solar system, that meant they were planets. When the numbers started to get into the 20's, everyone decided to create a new category, "asteroid" (Greek for 'star-like') and put all of the smaller things in that. So when Pluto was discovered in 1930 it was slotted right into the planet category. Pluto was discovered mostly by accident, because Clyde Tombaugh was amazing at working the blink comparator, and finding the one dot that moved in between the two pictures of the night sky a few days apart.
However, by the 1990's and 2000's you had computers and digital cameras, which are even better than Clyde at finding things that move, and quickly the number of planets started to go up- and it was clear that once we had thoroughly mapped the ~~Oort Cloud~~ (meant Kuiper Belt, see below) etc. we would have dozens of planets. And so once again astronomers decided to create a new category, just like they had with asteroids a century earlier. This time they drew the line in such a way that Ceres got moved from asteroid to dwarf planet- it has enough mass to be roughly round, so after over a century of being an asteroid it became a dwarf planet.
This is how things always work in science: we discover something, then we discover more of them, and re-categorize everything based on the new discoveries. It's just more noticeable with Pluto because reciting the planets is done by every schoolkid in a way that they don't for subatomic particles or for species of voles or whatever.
> thoroughly mapped the Oort Cloud
So it’s interesting that the Oort Cloud is often mentioned as a real thing. Surely there are plenty of bodies discovered which are orthogonal to its existence, but Oort’s “Cloud” itself still enjoys only the status of hypothesis and not reality.
https://en.wikipedia.org/wiki/Oort_cloud
Sadly, even Wikipedia editors seem unable to distinguish between the formal definitions of “hypothesis” vs. “theory” when delivering such a scientific article.
You are correct, I meant to say Kuiper Belt, not Oort Cloud, pulled the wrong thing out of my memory. Unlike the Oort Cloud, we are doing a good job of mapping KBO's as we speak.
If the furthest objects of the Oort Cloud are over 3 light years away, it is relatively close to Alpha Centauri.
Is there a chance that Alpha Centauri also has its own cloud that overlaps with it?
Would AC influence the cloud and adjust the orbit of smaller comets?
There's a chance, but no one knows for sure.
Oort Clouds are mostly empty space, so there wouldn't be much direct interaction. But there would certainly be gravitational effects.
My guess (FWIW) is there's more out there than we suspect, likely including plenty of rogue/wandering planets between systems.
And that, boys and girls, is how Neil deGrass Tyson got Pluto demoted. (I kid).
I still think he did it because he wanted to have his name on something significant. He’s a science communicator, not a researcher, and he’s not going to be making any discoveries. So he’s gotta change something that already exists to have his name on something that everyone knows. He had the power to change its status, so he did. I think that’s all it was. I hope I’m wrong but I’ve never heard a really GOOD reason to undo something that was so commonly known and taught. The definition for “planet” could change and Pluto could have been left alone, grandfathered in, in a way. There’s a reason it was discovered first. It’s huge compared to other dwarf planets.
There’s no reason that Pluto couldn’t have remained a proper planet. It’s big enough to be round and its largest moon is big enough to be round. Mars doesn’t have any round moons. Mars is still a planet.
He didn't "do it", he was one voice among many astronomers who have been calling for a reclassification for years, the IAU voted and made the decision. It's a little silly calling him out for "doing it" for ego reasons when you are the one implicitly giving him credit for it... He didn't write the definition, he didn't chair the committee, he wasn't even on the committee. All he did was leave it off the list of planets at the Hayden Planetarium, where he was director.
> The definition for “planet” could change and Pluto could have been left alone, grandfathered in, in a way
This doesn't sound like a science way of doing things. The definition of planet would have to be literally changed to add "Or has to have been discovered before 19XX" in order to keep Pluto without becoming an unbounded set. If you're annoyed at all the pedants correcting kids or anyone else talking about the nine planets, I'd take it up with them for uselessly debating such a fine distinction, like a chemist arguing about the word "Sodium" on a Nutrition Facts label.
I would argue the colloquial definition has indeed been changed in the above way, in that most people would say that what Mars, Venus, and Pluto have in common is they're all planets, and only a few would remember the odd factoid that the dwarf planet designation was created.
It's okay for the colloquial definition to be different than the scientific one. There isn't any use case where that will harm anyone. It's not like we're chartering flights to "All Planets" where space tourists are going to be ripped off, limited to 8 planets by the technicality and missing out.
You’re probably right, but I still think there’s room for things like this.
What’s a “moon” versus a “planet”? Earth is a moon of Sol, is it not? Why is having a lot of planets a problem in the first place? Why do we have to restrict the definition at all? If 2-3 stars are at the center of a star system, are the planets in that star system planets, or something else? What if they’re small?
This whole scene is ripe for people who want to put their stamp of opinion on something to go nuts arbitrarily.
What’s a “moon” versus a “planet”? Earth is a moon of Sol, is it not?
We already have the word "satellite" for "things that go around other things" right? I think "moon" is just "satellite of a planet" for convenience in discussing that subset.
> Why is having a lot of planets a problem in the first place?
I think keeping the number manageable is explicitly something we keep around to help kids grasp the main entities in the solar system. If we just said "there are 235 planets" it would be silly to try to teach them all, so we'd probably just settle for "The top 10 biggest planets" or something. Having a definition instead of a number to bound the set isn't much less arbitrary than teaching the "top 10," but since the long tail clearly starts after #8, "Top 8" would be the only guaranteed stable set to give special treatment to, which is what we've arrived at with the official definition.
> Earth is a moon of Sol, is it not?
No. The sun is a star, so it doesn't get to have moons. It has planets. If Jupiter started generating heat from nuclear fusion reactions, we'd call Io a planet right before we boiled to death, and with our dying breath we'd add "and also, it's no longer a moon".
Putting a leash on a cat doesn't make it a dog, and both of those creatures have four legs even if you call the tails of each a leg. A planet revolves around a star, a moon revolves around a planet (revolving around a star). There's further elements which make Ceres and Ed White's lost glove not a planet or a moon, respectively, but planets and moons are distinct and non-overlapping categories.