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Twenty New Moons Found Orbiting Saturn
- Razengan 7y agoIt’s amazing that we still keep discovering so many new things in our own neighborhood, and as another comment notes, still hard to keep track of things as relatively close as Saturn’s “lost” moons. This makes it kind of silly whenever we make confident assumptions about how much of X or Y must be out there in the rest of the Universe. (Not to knock the efforts of people who did accurately predict many facts about faraway phenomena while being stuck on Earth.)
- typpo 7y agoHere's a visualization I made of the Saturn system with an option to highlight the newly discovered moons: https://typpo.github.io/spacekit/examples/saturn/index.html https://typpo.github.io/spacekit/examples/saturn/index.html Besides the 20 new moons, I find it interesting that there are 8 "lost" moons. These are objects observed as far back as 2004 - but their current locations are unknown.
- flattone 7y agoI am in heaven playing with this. Sorry but this is the end of my comment.
- vibrio 7y agoI wanted to say this, but since you did already, I'm going back to playing with the moons...
- jakeogh 7y agoFun. Is there a way to accelerate?
- cydonian_monk 7y agoThis, your other examples, and spacekit as a whole are absolutely amazing. Thanks for sharing this link.
- deepaksurti 7y ago+10 for spacekit [0] [0] https://typpo.github.io/spacekit/ https://typpo.github.io/spacekit/
- gojomo 7y agoPlanets sprouting new moons, flinging off old moons – reminds of the 1983 coin-op video game, 'Mad Planets': https://en.wikipedia.org/wiki/Mad_Planets https://en.wikipedia.org/wiki/Mad_Planets
- saagarjha 7y agoIs there a reason why moons don't seem to orbit above Saturn's poles?
- frabert 7y agoMoons generally orbit on the same plane as their planet's orbit plane
- saagarjha 7y agoIs this because polar orbits are unstable in some sense, or because pretty much everything already is in the planet's plane?
- frabert 7y agoMostly because of conservation of angular momentum: the solar system formed while spinning, and that direction has been maintained. The cases where this is not true (for example, Uranus has its poles "facing the plane" instead of having them orthogonal to it) are likely due to past collisions with foreign bodies that caused the tilt to appear.
- saagarjha 7y agoAre most of these moons from when the solar system formed?
- twic 7y agoMaybe not, but the angular momentum is. Without a big input of energy and momentum to cause a plane change, anything that forms in the solar system will orbit roughly in the plane of the ecliptic, and will spin on an axis normal to it.
- raattgift 7y agoThat's a good question, and I don't think you'll find an especially convincing answer. Polar orbits are "unstable" in a few senses, namely that even in an ideal setting orbital planes will precess around central masses that are lumpy rather than spherically symmetric; rotation of a lumpy central mass introduces further precessions. Nodal precession is pretty interesting, for example. One can concoct all sorts of odd orbital changes by perturbing the rotating central mass "under" a test object in stable orbit. However, in the case of known solar system bodies, slowly shifting a satellite in near-polar orbit into a near-equatorial orbit conflicts with quite a lot of evidence; by the mid 1960s it was pretty safe to say that known inner moons maintain over very long timescales an almost constant orbital inclination with respect to the planet's equator, while outer moons maintain an almost constant orbital inclination with respect to the invariable plane of the solar system. Interesting exceptions are Triton and Earth's moon, both of which have significant inclinations to their planets. Precessions are primarily driven by the planet for the inner moons, and by the sun for the outer moons. It's probably worth paying some close attention to Uranus and its known moons (and their formation and/or capture) when considering the various thoughts people have put into the thread. Most of the moons and rings have negligible inclination (i.e., they're coplanar with Uranus's equator), and Uranus's extreme axial tilt is intriguing. If the tilt is because of a giant collision, did the relevant moons and rings follow the planetary tilt? Or did they form in the highly-tilted equatorial plane (for some of the moons), or were they captured into the equatorial plane (for others) post-tilt?
- NotSammyHagar 7y agoThat visualization is awesome! Everyone try it. You can easily zoom in and our and rotate in any of the 3 axis. It's amazing to see how far away these 'new moons' are from being in the same plane as the older, larger moons.
- kzrdude 7y agoIs there an astro term for differentiating the planar moons and the outer ones? That moon cloud looks like as if it is Saturn's Kuiper belt or Oort cloud.
- kkaranth 7y agoVery cool! I'm surprised that they orbit so quickly!
- typpo 7y agoThe speed measurement in the viz adjusts "visualization days per real second". It's set at 0.1 because the inner moons orbit very quickly. Pan orbits Saturn every 14 hours whereas Fornjot, the outermost named satellite, orbits every 1354 days.
- cheyne_nz 7y agoVery cool! It would be nice if there was a 'Highlight None' option in the drop-down.
- typpo 7y agoThanks! I've added this now.
- enriquto 7y agoImpressive! It looks just like celestia! I'm in awe
- Buttons840 7y agoI couldn't find any information about the "lost" moons you mentioned. Tell me more. What is the name of one or all of those moons?
- typpo 7y agoThe moons are: S/2004 S 7, S/2004 S 12, S/2004 S 13, S/2004 S 17, S/2006 S 1, S/2006 S 3, S/2007 S 2, S/2007 S 3. There are short Wikipedia articles for each one. JPL provides orbital elements but presumably they are not quite correct, otherwise we could locate them: https://ssd.jpl.nasa.gov/?sat_elem https://ssd.jpl.nasa.gov/?sat_elem
- xwdv 7y agoI wish they would open up the naming of at least one moon to whatever the internet decides to come up with, rather than restricting it to the same old boring gods and goddesses convention. That moon would probably become one of the more popular celestial bodies in the solar system based on that alone.
- saagarjha 7y agoI hope you're ready for Moony McMoonface, or something less printable…
- ISL 7y agoSomeone out there is working really, really hard to compose a phonetic Moony McMoonface from among the available phonetic options.
- journalctl 7y ago“Today, class, we’re going to learn about Saturn’s newest moon, whose name the district has forbidden me from actually saying.”
- AgentME 7y agoThink of all the confusion that could be caused if the voted name was actually "whose name the district has forbidden me from actually saying".
- airstrike 7y agoLike setting your wifi password to "FOURWORDSALLLOWERCASE"
- Buttons840 7y ago"And tomorrow, we'll be discussing Uranus."
- majewsky 7y agoI vote for the name being the Unicode character U+1F315.
- kupopuffs 7y agoNooo, my sci-fi novels!!
- Yuioup 7y agogit commit -am 'Needs more moons'
- ForceOfPhil 7y agoChristopher Walken cowbell style Waow!
- deleted 7y ago[deleted]
- kzrdude 7y agoA peeve I have would be to use a language of certainity ("has moons"): > This brings the ringed planet’s total number of moons to 82, surpassing Jupiter, which has 79 When it's clear we don't have the absolute truth. We need to be humble. It's clear then that Saturn has at least 82 moons. Or maybe not even that, taking account the "lost" moons mentioned in this discussion. Now we believe that Saturn has about 82 moons.
- Heliosmaster 7y agomaybe they should have just said they are the 'known' moons.
- jcbrand 7y agoThis is a problem with science reporting in general. Current theories or observations are presented as absolute truth even though they're only approximations of the truth based on our current data and understanding of what's really going on.
- Isamu 7y ago>language of certainty ("has moons") I don't read it that way. This is a science topic, I think the phrase "Jupiter, which has 79" does NOT mean "no more than 79" but does mean at least 79 that we know. I don't think it signals a lack of humility. I think it is just shorthand for "Jupiter has 79 moons, that we have verified". Since this is in the context of discovering more moons that we hadn't seen before, I don't think the extra verbiage is necessary and is implied. Of course we are in the process of discovering more moons. That's what the entire article is about.
- carlob 7y agoI wonder when these are gonna go the way of Pluto: Saturn has n moons and a shit-ton of dwarf moons. Wouldn't know where the threshold is though, because something like Phoebe is an absolute outlier.
- taneq 7y agoThat was my immediate thought - that the definition of ‘moon’ must have recently changed.
- nsilvestri 7y agoCurrently, the only way the definition of 'moon' can change is if it gets defined at all.
- dwoozle 7y agoAny notion of why the Earth has only one moon and other planets have hundreds?
- frabert 7y agoThe Earth is miniscule in comparison to the planets that have hundreds of moons. Those just have a stronger gravity field
- Yajirobe 7y agoWhat about Mars?
- ehnto 7y agoIt only has two moons, one more than earth for sure but nothing compared to the more massive planets.
- Sebb767 7y agoMars has even less mass than earth (5.972 × 10²⁴ kg vs 6.417 × 10²³ kg)
- dragonwriter 7y agoMars has two itty-bitty moons, and the other two terrestrial planets have zero moons. Earth’s moon has something like 99.99998% of the mass of all moons of terrestrial planets.
- magduf 7y agoThe "moons" of Mars are really nothing more than asteroids; they're a tiny fraction of the size of our Moon, and not even large enough to be round.
- dmead 7y agoyea. https://en.wikipedia.org/wiki/Circumstellar_habitable_zone https://en.wikipedia.org/wiki/Circumstellar_habitable_zone my understanding is that a good feature of the goldilocks zone is that it has fewer small objects than the outer planets region. maybe someone with better knowledge can pipe up.
- prewett 7y agoWe had the Cassini spacecraft in the Saturn system for 10 years, and in the past two years we've found 32 new moons! We've found 67% more moons with earth-based telescopes than we discovered actually being there. Wow, space is big and we know nothing. (Of course, I don't think Cassini was actually looking for new moons on the outskirts, but still, I'm surprised we didn't accidentally find some of these...)
- m0skit0 7y agoCassini's instrumentation was focused on studying surfaces, not finding moons https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens#Instruments https://en.wikipedia.org/wiki/Cassini%E2%80%93Huygens#Instru...
- dimitar 7y agoIsn't the term moon devalued too much by now? Isn't there terminology to classify these newly found 5km natural satelites differently from the massive moons like ours, Ganymede, Europa and so on? Something like dwarf moons or micromoons?
- benibela 7y agoCall them dwarf moons, until they have cleaned away the other moons
- MisterTea 7y agoHow about space stations?
- redwall_hp 7y agoI propose "mμns."
- perseusprime11 7y agoHow come we are finding these new moons around Saturn just now? Did we not see them before?