APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3021
Joined: Fri Dec 04, 2009 3:27 am

APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby APOD Robot » Tue Oct 10, 2017 4:11 am

Image Milky Way and Zodiacal Light over Australian Pinnacles

Explanation: What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains a topic of research. The panorama was taken last month. A ray of zodiacal light, sunlight reflected by dust grains orbiting between the planets in the Solar System, rises from the horizon near the image center. Arching across the top is the central band of our Milky Way Galaxy. The planets Jupiter and Saturn, as well as several famous stars are also visible in the background night sky.

<< Previous APOD This Day in APOD Next APOD >>

Boomer12k
:---[===] *
Posts: 2113
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby Boomer12k » Tue Oct 10, 2017 7:08 am

Cool...Mate...
Yeah, me and the Sheila and the Dingo went out one night....

:---[===] *

Petrus

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby Petrus » Tue Oct 10, 2017 8:19 am

Why does the Milky Way look like an arch? Is it because the Earth is out of the galaxy plane? Or is it in some way due to the use of wide field cameras? Maybe this is a trivial question, but I would like to understand more of these beautiful pictures.
Thanks a lot in advance.

User avatar
Case
Commander
Posts: 552
Joined: Sat Jun 09, 2007 10:08 pm
Location: (52°N, 06°E)

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby Case » Tue Oct 10, 2017 10:19 am

Image
Petrus wrote:Why does the Milky Way look like an arch? Is it because the Earth is out of the galaxy plane? Or is it in some way due to the use of wide field cameras?

It is like looking at a straight line on a dome. It is circling all around us, but we see a section that is above the horizon. With a wide field view of the 3D world projected on a 2D image, you'll end up with an arch.

Not just the Milky Way, the road is probably straight from left to right, too.

dlw
Ensign
Posts: 57
Joined: Fri Jul 22, 2005 4:43 pm
Location: California

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby dlw » Tue Oct 10, 2017 5:11 pm

There are also at least 2 meteors, one just right of center.

Beautiful image!

User avatar
Ann
4725 Å
Posts: 8494
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby Ann » Tue Oct 10, 2017 5:54 pm

Plane of the solar system and plane of the Milky Way.
NOT to scale!
Source: http://www.scienceminusdetails.com/2012 ... eways.html

Yes, it's a fine image. It's interesting to see the the zodiacal light more or less crossing the Milky Way. I don't know if this says anything about the orientation of the plane of the Milky Way in relation to the plane of the Milky Way, but their respective orientation is different, that much is certain!

Ann
Color Commentator

User avatar
geckzilla
Ocular Digitator
Posts: 8674
Joined: Wed Sep 12, 2007 12:42 pm
Location: Modesto, CA

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby geckzilla » Tue Oct 10, 2017 6:06 pm

Ann wrote:
Plane of the solar system and plane of the Milky Way.
NOT to scale!
Source: http://www.scienceminusdetails.com/2012 ... eways.html

Yes, it's a fine image. It's interesting to see the the zodiacal light more or less crossing the Milky Way. I don't know if this says anything about the orientation of the plane of the Milky Way in relation to the plane of the Milky Way, but their respective orientation is different, that much is certain!

The zodiacal light follows the ecliptic, so you are seeing the exact orientation of our solar system.
Just call me "geck" because "zilla" is like a last name.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 14475
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: Milky Way and Zodiacal Light over... (2017 Oct 10)

Postby neufer » Tue Oct 10, 2017 8:54 pm

geckzilla wrote:
The zodiacal light follows the ecliptic, so you are seeing the exact orientation of our solar system.
https://spiral.imperial.ac.uk:8443/handle/10044/1/1333 wrote:
A survey of radial velocities in the zodiacal dust cloud
Author(s): May, Brian Harold
Item Type: Thesis or dissertation

Abstract: This thesis documents the building of a pressure-scanned Fabry-Perot Spectrometer, equipped with a photomultiplier and pulse-counting electronics, and its deployment at the Observatorio del Teide at Izaña in Tenerife, at an altitude of 7,700 feet (2567 m), for the purpose of recording high-resolution spectra of the Zodiacal Light. The aim was to achieve the first systematic mapping of the MgI absorption line in the Night Sky, as a function of position in heliocentric coordinates, covering especially the plane of the ecliptic, for a wide variety of elongations from the Sun. More than 250 scans of both morning and evening Zodiacal Light were obtained, in two observing periods – September-October 1971, and April 1972. The scans, as expected, showed profiles modified by components variously Doppler-shifted with respect to the unshifted shape seen in daylight. Unexpectedly, MgI emission was also discovered. These observations covered for the first time a span of elongations from 25º East, through 180º (the Gegenschein), to 27º West, and recorded average shifts of up to six tenths of an angstrom, corresponding to a maximum radial velocity relative to the Earth of about 40 km/s. The set of spectra obtained is in this thesis compared with predictions made from a number of different models of a dust cloud, assuming various distributions of dust density as a function of position and particle size, and differing assumptions about their speed and direction. The observations fit predominantly prograde models fairly well, but show a morning-evening asymmetry, different in the two observing periods. Models are investigated containing various components, including prograde and retrograde orbiting dust around the Sun, a drift of interstellar material though the Solar System, and light from distant emitting matter. The implications for possible asymmetries of the Zodiacal Cloud are discussed.

Other researches on the Zodiacal Dust Cloud, before, during, and after my observations, are reviewed, including recent insights into its structure, orientation, and evolution, up to the present day, and my observations are evaluated in this context. Period of study, 1970-2007.
Art Neuendorffer


Return to “The Bridge: Discuss an Astronomy Picture of the Day”

Who is online

Users browsing this forum: CommonCrawl [Bot], neufer and 2 guests