"Flares" in Eris Photo (APOD 18 Sep 2006)

smitty · Post by **smitty** » Mon Sep 18, 2006 10:03 am

Anybody have any knowledge regarding what appear to be some sort of prominent "flares" (for lack of a better term) at the 11 and 5 oclock positions in the photo of Eris, APOD, 9/18/06?

astro_uk · Post by **astro_uk** » Mon Sep 18, 2006 10:35 am

Its hard to tell for sure but its almost certainly to do with the Earths atmosphere. The bending of light by the atmosphere changes rapidly tending to smear the light out, you can see this in the wikipedia article

http://en.wikipedia.org/wiki/136199_Eris

Look at the video you can see how the stars in the field appear to change shape between frames. This can make objects look less round.

The "flares" are probably just light scattered from the main light source (Eris). They could also just be faint background stars that are also being scattered.

ckam · Post by **ckam** » Mon Sep 18, 2006 10:36 am

it's... the... alien space station skyscrapers, yay! finally, we are not alone!

orin stepanek · Post by **orin stepanek** » Mon Sep 18, 2006 12:38 pm

http://antwrp.gsfc.nasa.gov/apod/ap060918.html

Maybe populated with dwarfs.

Orin

Dr. Skeptic · Post by **Dr. Skeptic** » Mon Sep 18, 2006 12:53 pm

At twice the distance as Pluto the anomalies are most likely a lenses or tracking aberrations and not eruptions, a ring system or physical structure.

ckam · Post by **ckam** » Mon Sep 18, 2006 1:11 pm

orin stepanek wrote:Maybe populated with dwarfs.

what ya mean "maybe", everybody know it's dwarf planet.

LSTolo · Post by **LSTolo** » Mon Sep 18, 2006 3:40 pm

Some years ago, a Voyager space craft spent some time near Jupiter, then set out to leave the solar system. When it passed the orbit of Saturn and Pluto, I was happy to hear it had presumably left the solar system and entered the farther reaches of the universe. Now with the discovery of Eris as part of our solar system, has the time capsule on the Voyager spacecraft passed that orbit or is it still within our solar system? If it has not crossed that orbit, when is it expected to do so?

astro_uk · Post by **astro_uk** » Mon Sep 18, 2006 3:58 pm

Hi LSTolo, welcome

I'm not sure if either Voyager has passed Eris, however the traditional definition of the edge of the solar system is the Heliopause, where the suns influence is equal to that of interstellar space.

http://en.wikipedia.org/wiki/Heliopause

Both Voyagers are still several years away from crossing the the Heliopause, I don't think anyone is certain how long it will be until they cross it, but the current estimate is 2015.Hopefully they will have enough power to report back when they do. It will be a shame if they run out of power before they do.

iamlucky13 · Post by **iamlucky13** » Mon Sep 18, 2006 9:04 pm

I don't think there's any question as to whether or not they'll have power to transmit. They're powered by nuclear RTG's that produce steady power for years (~25, I think), before slowly tapering off. The bigger question is will it be strong enough to hear, and even more importantly, will we still be paying people to listen? NASA has recently been seriously discussing concluding the Voyager mission completely due to the cost of the mission staff and scheduling communication times on the relatively small number of very busy radio antennae that are sensitive enough to pick up the signal.

I don't know if communication with the Voyagers is handled by the Deep Space Network antennae or some of the bigger ones, like the Arecibo or Parkes radio telescopes. The latter are only designed to listen, not transmit, and I assume instructions are still needed to tell them when to send back data.

I sure hope we're still listening to them when they reach that point, but I don't know how much value they really offer. It could be that the instruments onboard aren't specific enough (they were designed to survey the solar system, not test the waters of interstellar space) to accomplish anything more than confirm the most obvious bits and pieces of our theories about what's around us.

Still useful: Yes

Worth the cost: I hope so. Just being able to confirm where the heliopause is exactly might tell us a remarkable amount about interstellar space.

Qev · Post by **Qev** » Tue Sep 19, 2006 12:42 am

Per our friend, the Wikipedia:

Wikipedia wrote:As of September 5, 2006, Voyager 2 is at a distance of around 80.5 AU (approximately 12 terameters) from the Sun, deep in the scattered disc. It is more than twice the distance from the Sun as Pluto, and far beyond the perihelion of 90377 Sedna, but not yet beyond the outer limits of the orbit of Eris.

mwinnett · Post by **mwinnett** » Wed Sep 20, 2006 1:50 pm

Greetings,

I am a big fan of astronomy picture of the day, but have no other 'training' in astronomy other than what I learn from the website and its links. The picture on 9/19 induced me to follow all the links to Wikepedia, starting with dwarf planets. Wikepedia lists Eris as orbiting in the scattered disc (which it further describes: 'The innermost portion of the scattered disc overlaps with the Kuiper belt, but its outer limits extend much farther away from the Sun and above and below the ecliptic than the belt'). The astronomy picture of the day lists Eris as orbiting in the Kuiper belt.

Is this a semantics thing? Just curious....

Also, what about the multiple shadows of the moon (?) on today's picture - an effect of the lens?

MNMary

BMAONE23 · Post by **BMAONE23** » Wed Sep 20, 2006 2:04 pm

If you are refering to the spheres in the middle of the image, I believe they are referred to as "Lens Flares" which are reflections of the sun on the camera's internal lenses.
As for the other part of your question, I'll await others replies too.

Leaves · Post by **Leaves** » Wed Sep 20, 2006 9:37 pm

Just a thought on the APOD keck Observatory photo of Eris on September 18:

http://antwrp.gsfc.nasa.gov/apod/ap060918.html

Has anyone considered that the two "spikes" of light from the planet, (not the moon) may be rings?

craterchains · Post by **craterchains** » Wed Sep 20, 2006 9:47 pm

hmmmmmm good thought!

Norval

BMAONE23 · Post by **BMAONE23** » Thu Sep 21, 2006 1:20 am

anything is possible

In this image from Cassini http://photojournal.jpl.nasa.gov/catalog/PIA08323 it would almost appear like the Earth has a ring in the plane of the moon (which is the small bulge in the image at the 10:30 position) The proposed ring would be the slight flare at the 4:30 position, opposite the moon.

harry · Post by **harry** » Thu Sep 21, 2006 3:43 am

Hello All

The two spikes from the image I think are photo somewhat errors.

No rings
I could be wrong.

Although theoretically there should be a gravitational ring in line with the moon.

NeoEspiritus · Post by **NeoEspiritus** » Wed Sep 27, 2006 3:46 am

this is going to sound dumb to people who know the answer, but I've been wondering for a while now...

Why is is that we can get crystal-clear images of galaxies millions of light-years away and nebulae hundreds of light years away, but all the images of something a couple hundred million miles away come back looking like sonogram pictures? Someone please enlighten me!!

dcmcp · Post by **dcmcp** » Wed Sep 27, 2006 5:07 am

NeoEspiritus wrote:Why is is that we can get crystal-clear images of galaxies millions of light-years away and nebulae hundreds of light years away, but all the images of something a couple hundred million miles away come back looking like sonogram pictures? Someone please enlighten me!!

See this thread

NeoEspiritus · Post by **NeoEspiritus** » Wed Sep 27, 2006 1:21 pm

Thanks

Starship Asterisk*