Green Baron

@KG3: The Ryugu guys execute their right to choose the reference frame :-) But i think the question was "Isn't there a universal fixed reference frame ?" and the answer is no. If at all, it "quasi fixed" but only for a limited time. Changes must always be taken care of, which results in transformations and feeding formulas with elements who describe the changes and the time for which they are valid.

Well, it has no inclination relative to its own ecliptic. I am not sure, but i think the icrf ecliptic has been fixed is relative to the solar system barycenter, to which the earth's orbit changes. Though the changes are minimal (<<1 arcsecond/year), they must be observed for high precision astrometry. So, yeah, the earth's ecliptic has an inclination relative to the icrf ... Again i hope i got that right :-)

For objects in the solar system that would be the ICRF (International Celestial Reference Frame). But for specific applications other frames can be chosen, for example the ecliptic of a satellite. If the object's rotation is not known, it is assumed to be normal to the ecliptic of the object's orbit around its parent body. Hope i got that right. Inside this there is a link to a paper describing the dirty details. I just found it via my search fu. Coordinate transformation is a main chapter in books on astronomy :-)

Yeah, pretty fast. That'll be a block of several, maybe 10km. It can't gain much more than 11km/s when you release it from your grip at edge of earth's gravitational pull without an additional finger snip. That'll be Xicxulub 2.0 or bis, then, but softer. It won't kill everything. You'd need moar. Like one of those boulders from the older solar system.

Hehe. Sure it wasn't just "handle with care" printed on an endless tape ? Honestly, a single word that "wraps all the way around" doesn't exist in German, even in super large letters. If you have a better hint or a link to the website we could try and find out what that was. Edit: Spanish has some nice constructs, e.g. from a verb, article and reflective pronoun (hope i got that right) in one word. It is a language for short and on the point information exchange :-)

I am German. Actually, German language does not have more combined words than other languages like English or Spanish. It comes mostly with the description of technical things, that a verb and a noun are combined, to describe that "something is doing something", like "Laufband" from laufen (to run) and Band (belt), would translate to conveyor belt. And there are different versions, for the transport of people, raw materials or end products, which might to an outsider look and sound confusing. But in the end it is rarely more than two words (though they exist) that form a new one, and if it is it frequently comes from politicians or lawyers (oops :-)). In these cases the word will be difficult to find in an official dictionary and is absolutely to be ignored in every day life because its (un-)intended connotations tend to be arbitrary and are likely to cause ambiguities or leave a backdoor. We have of course our jokes about word-monsters like Donaudampfschiffahrtsgesellschaft a classic, which means "Company for steam boat trips on the Danube". That's my tribute to the op :-) Be it as it may, it is frequently not the best method of speech to complicate things or create neologisms. :-) Edit: oh, by the way, neologism, translated to German, has 3 ingredients in it: Wortneuschöpfung Word-new-creation :-)

The light source is not directly behind ...

Very nice ! Not pretending to be right, but the shadows are a hint to an independent light source if the craft doesn't have long arm with a flashlight. It would make sense to close in in an area where there are shadows, to get a feeling of depth and structure. The darker rim looks like typical vignetting as in any optical system. Edit: It shows so prominently because of the uniform grey tone of the picture. A hill/small mountain of ~600m height (*). A supertanker has magnitudes less (~3-4 of them). (*)Edit: i am ignoring the lower density of an asteroid compared to the more compact earthly sediments.

Two alternating flutes parting in an accelerating piece. You'd need stereo speakers, and it is a dynamic piece of music. And a terrible earworm :-) Ichu - Sicuriada, 1982. For the technophiles: the original is an extremely well made direct to disc recording ("direct cut"). I can compare vinyl and CD; the CD cannot compete and this bitstream is only a weak echo. Nevertheless:

If one wants to carry on, one should always fly again/ride again/dive again whatever as soon as possible after an accident to regain self confidence. Carefully but decidedly. Talk with trustees who know the sport helps as well to get to the causes and how to avoid them. Otherwise the uneasy feeling sets in the mind, and if anxiousness blocks the mind one can and will never do it again.

Man, that sounds heavy. Glad your still among us. You're not alone with that experience. I crashed with a paraglider 2004 when trying to land on a narrow hill top. I have nobody to blame, it was just too much self confidence. Get well !

These roads are coming. With all the cheap money dealt out by the central bank everything is plastered in asphalt or concrete (that was my complain part of the day :-)). But there still are a few dust roads, and not all roads are renewed yet. In many places one has to stop to let a semitruck or a bus pass through or do slowly because one can't look around a corner. But nobody damages anything wilfully. I actually once drove a car that came without a spare tire, only that spray-through-the-valve nonsense, though it even was a high priced company car. But that thing doesn't help when the tire is cut and not just punctured. I know of no compact car like mine today that would allow for a full size tire even as an extra. And many don't even offer an emergency spare tire ... And many suvs carry the spare tire on the back only for the optics i'd say. If it is real at all, judging from who drives these cars i'd expect they couldn't even lift it down or dismount the aerodynamic shroud of it. Anyway, i got 2 new front tires now (because symmetric profile abrasion) and will go to town to pick up the car. See you :-)

A cool service from where i live: http://lapalma.hdmeteo.com/ I don't think you'd need translation ...

*lol* ... oh, "meaning" could be refined with "semantics" :-) I had a flat tire today. Drove over a sharp edge where a piece of asphalt had broken off. Was cutting a little through a narrow curve at 50km/h. The tire had a 5cm cut because it came between rim and asphalt. Fortunately the rim wasn't damaged. And i am glad that i had bought the extra "spare tire, for short distances, limited to 60km/h" when i bought the car. Otherwise that would have been expensive, calling a tow truck 7km to town ... My last flat tire was ... emmm, was .... aa ... in another millennium, that's sure.

And, before someone asks (which probably nobody will but i annoy you nevertheless), both turtles and tortoises are amniotes and reptiles who do not principally need water. Their eggs have a membrane/shell to keep the inside from drying out. :-)

Get well soon ! Space can wait ;-)

In principle: there are external and internal factors that drive earth's dynamics. In short, the border between those actually lies in the crust, where weathering and transport of rocks form sediments. Sediments, ice shields, etc. can exert forces on the earths crust, pressing it deeper into the softer Asthenosphere when they build up or letting it rise when they melt or when mountain ranges weather down. But these processes are slow, taking 100s to ~10.000 of years (ice shield dynamics) or even 10s of millions (weathering of mountain ranges). So, if there is a direct effect, it is slow and will probably not have any cataclysmic consequences or even be noticeable. The crust is a very effective insulator. It heats and cools over 10s of to ~200 millions of years, example oceanic crust from middle ocean ridge to subduction zone/continental margin, cooling from >1000 to 15°C. And crust has a certain porosity, continental is even less dense than oceanic. We are talking about 2.5 to 4 degrees global atmospheric warming in the coming decades, depending on modeling, with a fast rising tendency in the past years. While this will have (and already has) catastrophic consequences in the atmosphere, cryospehere and hydrosphere, i doubt that these changes will have enough time to influence the lithosphere and earth's crust, and they still are much too small for the material to expand. But of course, processes like weathering, melting etc. are also depending on temperature, just imo not enough to cause earthquakes that are distinguishable from those driven by the earth's internal forces. tl;dr: no probably not.

The shell is made from ribs, pelvis- and shoulder bone. It is not a "heat shield" and judging from its history of development i tend to negate its aerodramatic usefulness :-) Nope, but the RL expression would probably be hill sphere.

Good point ...

There is organic stuff enough in it from the wet sediment it was in. I do not know which animal it is from.

While it is definitely possible, even probably to find all sorts of rubbish in the ocean (one can't make even a short tour in protected areas without sighting any rubbish), it is difficult to give a definitive answer if you don't have experience. Best is to go to a museum with a collection for comparison and show it to someone who knows or directly compare. But the answer might be "yeah, its a vertebra process, but not from an animal we study here". Or "yeuch, begone with it" because sooner or later it'll start to moulder :-)

It is a defined mass, nothing more. And i don't always mean things totally serious. It totally depends on the application of that mass, which one can use to trivially calculate the acceleration a dead carcass can endure before is breaks. I mean, if one doesn't have centrifuge with a means to calculate the rpm at hand, which in my case isn't the case, at least not all the time. :-)

I yield. I didn't even think of a marine mammal vertebra at first. Yeah, i uttered my unsorted thoughts too loud. After a short check i had already ditched that, though lying around can make funny things with bones as dense as a tibia.

You may be right ... it is the asymmetry and the apparent robustness that leaves me doubting. Edit: if there is a museum in your area, you could take it there and compare it. In Stralsund, Germany that could easily be done. But it is a few 100km away :-)

You mean a transverse processus, or from a caudal vertebra from a big sea mammal ? Not sure, too robust i think and the broken looking end doesn't fit. I don't know what it is, but It looks like a fragment of a long bone to me, with missing epiphyses. My first bet was actually on a tibia from a landliving animal because of the triangular shaft, the distal end completely missing and the proximal epiphysis gone as well (maybe a younger animal at lifetime), and because they are quite robust. But after a short check i am away from that. I don't know what it is. You could show it off in an anatomy forum. Edit: sea mammal vertebra might have such processes, but they are connected to a big "drum" like structure, and that part looks to me more like a missing epiphysis. But i am not sure. It is a long time since i last had bones in my hands ...