APOD: When Mars met Neptune (2017 Jan 13)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3547
Joined: Fri Dec 04, 2009 3:27 am

APOD: When Mars met Neptune (2017 Jan 13)

Post by APOD Robot » Fri Jan 13, 2017 5:42 am

Image When Mars met Neptune

Explanation: On January 1, a Mars-assisted viewing opportunity allowed binocular-equipped skygazers to cross an ice giant off their life list. Remarkably, the line-of-sight to the bright Red Planet could guide you to within 0.02 degrees of a faint, pale Neptune in Earth's night skies. Taken within 3 hours of their closest conjunction, these panels capture the odd couple's appearance in skies over Brisbane, Australia. A wide field view includes the new year's slender crescent moon near the western horizon and Venus as the brilliant evening star. Mars and Neptune are indicated at the upper right. The two inset magnified views were taken with the same telephoto lens and so do show the Mars-Neptune conjunction and the apparent size of the crescent moon at the same scale. This week Neptune hangs out near Venus on the western sky.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

User avatar
Ann
4725 Å
Posts: 9513
Joined: Sat May 29, 2010 5:33 am

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by Ann » Fri Jan 13, 2017 6:19 am

I love the color contrast between Mars and Neptune! :D

Ann
Color Commentator

heehaw

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by heehaw » Fri Jan 13, 2017 10:17 am

When Galileo was first observing Jupiter, and thought the four moons were stars, Uranus was coincidentally nearby and I think appears in one or more of Galileo's drawings as a star. After some weeks Galileo figured out that those four "stars" were satellites, but he did not twig to Uranus.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 15967
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by neufer » Fri Jan 13, 2017 1:36 pm

heehaw wrote:
When Galileo was first observing Jupiter, and thought the four moons were stars, Uranus was coincidentally nearby and I think appears in one or more of Galileo's drawings as a star. After some weeks Galileo figured out that those four "stars" were satellites, but he did not twig to Uranus.
Galileo saw Neptune not Uranus.

(Galileo would have created a slight breach of etiquette by skipping Uranus and going right for Neptune.)
Art Neuendorffer

Stan

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by Stan » Fri Jan 13, 2017 3:30 pm

Darn, I would have liked to see this. Wish I had known.

User avatar
neufer
Vacationer at Tralfamadore
Posts: 15967
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by neufer » Fri Jan 13, 2017 6:09 pm

Stan wrote:
Darn, I would have liked to see this. Wish I had known.
  • I'll have what he's having.
Art Neuendorffer

User avatar
alter-ego
Serendipitous Sleuthhound
Posts: 828
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by alter-ego » Fri Jan 13, 2017 8:29 pm

Stan wrote:Darn, I would have liked to see this. Wish I had known.
Over the years, I've found this Sky & Telescope site quite helpful. Scrolling down through the observing articles you'll find the Mars Meets Neptune post.
A pessimist is nothing more than an experienced optimist

User avatar
MarkBour
Subtle Signal
Posts: 891
Joined: Mon Aug 26, 2013 2:44 pm
Location: Illinois, USA

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by MarkBour » Fri Jan 13, 2017 8:36 pm

Stan wrote:Darn, I would have liked to see this. Wish I had known.
Yeah, me too.
Next one I can see in a chart that looks good is:
December 7, 2018 14:55:51 UTC Mars 2' south of Neptune at 88.3° East
Mark Goldfain

User avatar
Fred the Cat
Theoretic Apothekitty
Posts: 579
Joined: Mon Feb 22, 2016 4:09 pm
AKA: Ron
Location: Eagle, Idaho

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by Fred the Cat » Fri Jan 13, 2017 10:40 pm

Don't you just love the language of the occult? Why is the hidden so much more a part of our fascination than what's obvious. Especially when it's just for an IOTA of time. Opposing, I suppose it'll be a while before Mars will actually hide Neptune. That's another mystery. :(
Freddy's Felicity "Only ascertain as a cat box survivor"

User avatar
alter-ego
Serendipitous Sleuthhound
Posts: 828
Joined: Mon Apr 21, 2008 4:51 am
Location: Redmond, WA

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by alter-ego » Sat Jan 14, 2017 7:12 am

Fred the Cat wrote:I suppose it'll be a while before Mars will actually hide Neptune. That's another mystery. :(
It's certainly a rare event, so yeah it will be a while. Except for year 2100, the 2017 and 2018 conjunctions are the closest through 2200.
  1. Mars occulted Neptune on Aug 25,1278. Their separation was ~0 arcseconds and the event lasted around 20 seconds
  2. On Aug 23, 2100, their separation will be 8 arcseconds. Given their diameters will be 3.6" (Mars) and 2.2" (Neptune), their limb separation well be ~6 arcseconds
A pessimist is nothing more than an experienced optimist

User avatar
neufer
Vacationer at Tralfamadore
Posts: 15967
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: When Mars met Neptune (2017 Jan 13)

Post by neufer » Sat Jan 14, 2017 1:20 pm

alter-ego wrote:
Mars occulted Neptune on Aug 25,1278.

Their separation was ~0 arcseconds and the event lasted around 20 seconds
Darn, I would have liked to see this. Wish I had known.
Art Neuendorffer