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Astronomers may have found the first exomoon

eso.org

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Re: Astronomers may have found the first exomoon

#41

Post by yreg »

molf wrote: post #7
pelagicAustral wrote: post #3

I know this is besides the article and all, but why would the Chilean flag be the only one to have 8px left margin? This is killing me...

I believe such organisations tend to do such things very intentionally :-) About ESO [1] > We are an intergovernmental organisation established in 1962 supported by 16 Member States (Austria, Belgium, Czechia, Denmark, Finland, France, Germany, Ireland, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom), our host country Chile and strategic partners. So Chile has a distinct s…

Obviously, how else would you do it rather than the standard left-margin notation for the host country :)

Re: Astronomers may have found the first exomoon

#43

Post by renegade-otter »

HelloUsername wrote: post #10

An important phrase from the article to consider before commenting: "This system is somewhat hard to define using Solar-System-based words like ‘planet’ and ‘moon’"

We don't really have that nomenclature. We just recently decided what a planet it for the solar system, and even that is contentious.

Re: Astronomers may have found the first exomoon

#45

Post by Aerolfos »

GolfPopper wrote: post #36
selectodude wrote: post #14

Earlier quoted context omitted.

I thought we’re supposed to call them dwarf planets now. Dwarf star, dwarf planet.

It's a problem of useful/meaningful labeling. 'Planet' comes from the Greek word for 'wanderer' which was very useful for labeling the handful of bright stars that moved through the heavens in a pattern. Then we got to the Space Age and kept calling them (and similar new additions) 'planets' even as we learned far more about them. And immediately there's a problem. Setting aside Pluto (and the Sun), you've still got…

> Astronomers have pretty good terminology for stars,

...do they though?

The "proper" terminology says all main sequence stars are dwarves, but nobody calls them all that in practice. Some astronomers insist on saying "yellow dwarf", but some don't really bother. In general having the only two kinds of star be "giant" or "dwarf" is contentious, but it's also contentious that there isn't a name for whatever is in the "middle". "Main-sequence star" is a broader category and doesn't apply. They're all "stars", obviously, so that isn't specific enough.

The only decent terminology is for the spectral classes, but those only work as long as you look at spectra. The moment you try to figure out what the theory says those stars would look like as proper 3D objects, things get very messy. You also immediately get the issue that star size and brightness goes O>B>A>F>G>K>M. So... it's alphabetic except it isn't. And C is something completely different and doesn't fit the brightness classification at all.

Re: Astronomers may have found the first exomoon

#47

Post by delta_p_delta_x »

GolfPopper wrote: post #36
selectodude wrote: post #14

Earlier quoted context omitted.

I thought we’re supposed to call them dwarf planets now. Dwarf star, dwarf planet.

It's a problem of useful/meaningful labeling. 'Planet' comes from the Greek word for 'wanderer' which was very useful for labeling the handful of bright stars that moved through the heavens in a pattern. Then we got to the Space Age and kept calling them (and similar new additions) 'planets' even as we learned far more about them. And immediately there's a problem. Setting aside Pluto (and the Sun), you've still got…

Even within stars the layman labels are a bit iffy; it is better to use the stellar classification. 'Dwarf' is badly overused, as is 'giant'.

Re: Astronomers may have found the first exomoon

#48

Post by somenameforme »

margalabargala wrote: post #44
replatformradar wrote: post #42

About time!, I cant wait till we start putting large hardware on the dark side of the moon. That will make JST look like a toy.

The far side of the moon is no more or less dark than the side we see.

It is from the Moon's perspective. On the visual spectrum the Earth is much larger and more reflective than the Moon. You're looking at something like 40x greater illumination during a 'full Earth' than you get during a full Moon on Earth. Earth is also extremely noisy in the radio spectrum for radio telescopes, while the Moon itself blocks most of all of that out on the far side.

Re: Astronomers may have found the first exomoon

#50

Post by ck2 »

Literally not a moon, that headline is ridiculous (not posters fault)

but Nancy Grace Roman Space Telescope WILL find Earth-sized exoplanets and even REAL moons

I am stupid-excited to see it launched/first-light in my remaining lifetime (Musk better not screw it up)

For perspective on the technology, JWST "only" has 28mbps downlink

NGR has 500mbps downlink, that's right 1.5 TERABYTES PER DAY download speed

all from ONE MILLION MILES AWAY in L2 (11 seconds ping time!)

Technology is getting amazing!

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