Eris, Sun, Dysnomia (APOD 19 Jun 2007)

[JohnD]

Dysnomia = 'bad name' in dog Latin?

[Carl Horn]

G'day,
The artist's view shows the sun in the background. Pictures I've seen of the sun as seen from Pluto show a small dot not much bigger than a star as seen from Earth. The sun in this picture as seen from Eris is much bigger. Which is correct?
Carl Horn
Nelson, New Zealand

[l3p3r]

I understand that this is just an artist's impression... but the picture is flawed in just about every way it is possible for such a picture to be flawed. The sun seems very big at two pluto orbits distance, Dysnomia is practically grazing the surface of Eris it is so close, the shadow on Dysnomia is pitch black whereas the dark side of Eris is partly illuminated.

I would say this picture, for example, is much more representative of the actual Eris system. http://en.wikipedia.org/wiki/Image:2006-16-a-full.jpg

[jimmysnyder]

In Greek mythology, Dysnomia was Eris' daughter. The word means lawlessness.

[Angus McPresley]

I understand that this is just an artist's impression... but the picture is flawed in just about every way it is possible for such a picture to be flawed. The sun seems very big at two pluto orbits distance, Dysnomia is practically grazing the surface of Eris it is so close, the shadow on Dysnomia is pitch black whereas the dark side of Eris is partly illuminated.

I would say this picture, for example, is much more representative of the actual Eris system. http://en.wikipedia.org/wiki/Image:2006-16-a-full.jpg

I came to this forum to say almost the exact same thing. The sun is WAY too big. It would look more like a bright pinprick from that distance.

The closeness of Dysnomia to Eris could just be perspective thing, though, I guess -- it could be a lot closer to the viewpoint. Which could explain how Eris' shadow could be partially illuminated -- it could be reflected off Dysnomia (given that the sun was that bright at that distance, which we know it would not be).

[l3p3r]

Hi Carl!
Seems we both posted the same thing - at exactly the same time! (to the minute)

http://asterisk.apod.com/vie ... hp?t=12366

[Kingslasher]

The only way the sun could appear that large in relation to Eris is in a telescopic view from much farther out. However, that would make the observer see almost entirely the dark side and since that is not the case, I agree the artist's perspective is deeply flawed.

[gargoyle]

100% on the mark.

I understand that this is just an artist's impression... but the picture is flawed in just about every way it is possible for such a picture to be flawed. The sun seems very big at two pluto orbits distance, Dysnomia is practically grazing the surface of Eris it is so close, the shadow on Dysnomia is pitch black whereas the dark side of Eris is partly illuminated.

I would say this picture, for example, is much more representative of the actual Eris system. http://en.wikipedia.org/wiki/Image:2006-16-a-full.jpg

[RichardSRussell]

I understand that this is just an artist's impression... but the picture is flawed in just about every way it is possible for such a picture to be flawed. The sun seems very big at two pluto orbits distance, Dysnomia is practically grazing the surface of Eris it is so close, the shadow on Dysnomia is pitch black whereas the dark side of Eris is partly illuminated.

I would say this picture, for example, is much more representative of the actual Eris system. http://en.wikipedia.org/wiki/Image:2006-16-a-full.jpg

I came to this forum to say almost the exact same thing. The sun is WAY too big. It would look more like a bright pinprick from that distance.

The closeness of Dysnomia to Eris could just be perspective thing, though, I guess -- it could be a lot closer to the viewpoint. Which could explain how Eris' shadow could be partially illuminated -- it could be reflected off Dysnomia (given that the sun was that bright at that distance, which we know it would not be).

I too came to this forum to say almost exactly the same thing.

However, since I always at least TRY to figure out a logical explanation for why something appears the way it does, I suggest that perhaps, in the artist's mind, this is what Eris and Dysnomia will look like after the Sun goes nova.

[Andy Wade]

I was going to say that Dysnomia looks more like one of those holes in the surface of Mars...
OK, I'll get my coat...

[salientNZ]

[quote="Angus McPresley"]
I came to this forum to say almost the exact same thing. The sun is WAY too big. It would look more like a bright pinprick from that distance.
[/quote]

I also came here to say the same thing. And also to rant a bit :-).
[rant]
Why is it that virtually every artist's impression on APotD is seriously flawed ! Show this picture to almost any Astronomer, and they'll tell you that it is seriously wrong.

In this case, the error is seriously compounded by describing the artist as a "scientific artist". Codswallop! There's sod all science in this picture.
[/rant]

Cheers,
Brent.

[JohnD]

Oh, come on!
They are "artists".
They "interpret reality".
A true image would show a tiny speck of light and a dim sphere. Where's the fun in that?

You'll be saying next that the Mona Lisa didn't really have a smile, that Monet was just a half blind old man and that Guernica would have been better served by a photograph.

John

[rigelan]

Codswallop? I like it.

[BMAONE23]

http://antwrp.gsfc.nasa.gov/apod/ap070619.html
Yes it is art for art's sake but if I were doing it, I would try to approximate the relative size of the sun as would be viewed from this distance. (It should be markedly smaller than it is) I would be certain that the lighting conditions would be proper enough to be believeable. (the lit surface shouldn't be any lighter than the dark side was depicted). Probably the biggest problem, the Lighting angle of ERIS is different than that of Dysnomia. (Granted that though Sun depicted is far too close, the lighting angles do receede back to the star)

It would be more likely a depiction of Gliese 581d

[rigelan]

Actually, i meant I liked the word 'codswallop'. The picture is nice too.

[Andy Wade]

Actually, i meant I liked the word 'codswallop'. The picture is nice too.

Cod's 'Wallop' is the eggs from the Cod fish. It's used as a general term (here in England at least) to describe anything that is useless, rubbish or undersirable. As opposed to Caviar, presumably.
Sounds good too, especially in an argument when you're describing someone else's point of view.
"You're talking a right load of old codswallop!"

[craterchains]

Cod's 'Wallop' is the eggs from the Cod fish. It's used as a general term (here in England at least) to describe anything that is useless, rubbish or undersirable. As opposed to Caviar, presumably.
Sounds good too, especially in an argument when you're describing someone else's point of view.
"You're talking a right load of old codswallop!"

Much of the so called "artist depictions" are just that, codswallop.
Please, and now scientific artist? Codswallop indeed, , ,

Norval

[l3p3r]

In this case, the error is seriously compounded by describing the artist as a "scientific artist". Codswallop! There's sod all science in this picture.

It's almost as bad as the "science" they claimed to have in that abysmal movie Sunshine!

[Chuck Bennett]

Last summer (June or July of 2007) you ran a picture of the planet Eris which you said was larger than Pluto. Is the the same as the rumored "Planet X" which is supposed to come close to the earth in 2012?

[Qev]

http://en.wikipedia.org/wiki/Eris_%28dwarf_planet%29

No, Eris is just a trans-Neptunian object, and the ninth-largest known satellite directly orbiting the Sun. Its orbit never brings it closer to the Sun than about 39 AU.

[Case]

http://apod.nasa.gov/apod/ap070619.html

[SittingDownMan]

http://apod.nasa.gov/apod/ap070619.html

Thank you for that one.
The picture on the day after that one
http://apod.nasa.gov/apod/ap070620.html
is also a lovely image. A view of three worlds, and a star off to the right.

Human beings have actually walked on two of the worlds in that image.


SDM