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[Centaur]

The elusive little planet Mercury has begun its apparition as a morning star following its inferior conjunction between Earth and Sun on 2012 JUL 28. This apparition will conclude with the planet’s superior conjunction behind the Sun on SEP 10.

My detailed article describing Mercury’s morning apparition appears under the links for my related graphics at www.CurtRenz.com/mercury

Photos and descriptions of Mercury during its current apparition would be welcome additions to this thread.

[Paulie pchris00]

Mercury in the morning. That reminds me that it's only 1374 days, 22 hours, and 23 minutes until the next transit of Mercury. ;D

[Paulie pchris00]

I really thought this would be the morning I finally saw Mercury with its inner planetary neighbor. It wasn't to be. There was a thick fog, more than what this picture shows. I scanned naked eye and binoculars, but couldn't find the quick rock through the muck.

Venus can be seen in the upper right.

Wow. I should have compressed that before uploading.

Sorry.

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[Paulie pchris00]

I finally saw Mercury during this morning apparition. This was taken Saturday morning at Conway Observatory. The little rock was at greatest western elongation August 16, 7 AM CDST. Venus was at greatest western elongation August 15, 4 AM CDST, just over a day before Mercury. That reminded me of another time I saw the two inner planets at greatest western elongation about a day apart.

pchris00pnc.blogspot.com/2011/01/greatest-western-elongations-of-inner.html

Do these two planets have an orbital resonance that I have never heard of? It seems strange that they should reach GWE about a day apart twice in less than two years.

Otherwise, I like Mercury's morning apparitions better. I don't know if I would get out of bed early just to see it, but rising in a dark sky makes it easier to spot than trying to catch it following the sunset during evening apparitions. So for anybody who has never seen Mercury, morning apparitions near it's greatest western elongation are the best times to try to catch it.

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[Centaur]

Aug 19, 2012 10:47:55 GMT -6 Paulie pchris00 said:

Do these two planets have an orbital resonance that I have never heard of? It seems strange that they should reach GWE about a day apart twice in less than two years.

Thanks for the photo and description, Paulie. That’s a fine question you have regarding a seeming resonance. No pair of major planets has a true orbital resonance between them, although there are always approximate repetitive cycles. Of course in this case it would have to have been a three-way resonance, since an earthbound observer is involved. Nevertheless, a precise physical resonance still does not exist.

An inferior planet’s synodic cycle is the period it takes to lap the Earth. In the case of Mercury this is 0.317255 Julian dynamical years at epoch J2000.0. For Venus it is 1.598690 years. Therefore there are 5.03913 Mercury synodic cycles for each one of Venus. This figure is near but not exactly the integer 5. The dates of the greatest western elongations of both planets did indeed nearly coincide with a separation of 1 Venus synodic cycle in 2011 JAN and 2012 AUG, which involved approximately 5 Mercury synodic cycles. However this relationship becomes quite noticeably out of sync during prior and succeeding GWE’s of Venus.

[Paulie pchris00]

Cool. I just found it interesting to see them at GWE so close to each other in such a short time span. All the more reason to appreciate when it happens that way. Thanks.

[Centaur]

Aug 19, 2012 16:41:52 GMT -6 Paulie pchris00 said:

Cool. I just found it interesting to see them at GWE so close to each other in such a short time span. All the more reason to appreciate when it happens that way. Thanks.

You're welcome, Paulie. Also keep in mind that comparisons were made between January and August positioning. Mercury's orbit in particular has a relatively high eccentricity. This leads to significant deviations from the mean timings that would be deduced from a set of idealized orbits with zero eccentricity.

[Paulie pchris00]

Some images from Wednesday morning, August 22.




Venus shines brightly in the morning twilight.








With Jupiter and Venus conveniently pointing the way, I found Mercury.







I also saw Sirius, the Dog Star. The bright point above it is a westbound aircraft.














Venus and Jupiter are not only rising much earlier than they did two months ago, but their angular separation is increasing.




Venus outlasts its inner planetary neighbor as sunrise approaches.

[Centaur]

Thanks for sharing your fine photos. Let's bow to Paulie and Venus.

[Paulie pchris00]

I have the advantage of being up all night almost every night. I don't think I'd be getting out of bed that early to see a fleet footed rock.