129 replies to this topic

[Rick Runcie]

Mars largest size it can attain is 25.6". If you start observing it now it's amazing how much you will see even when it's only 15".

Best regards, Richard

[azure1961p]

No it can get larger appearing than that. 

 

Pete

[Rick Runcie]

I guess to You it can appear larger than that, but in reality it can't. Check your facts.

Best regards, Richard

[Cpk133]

This morning i caught Mars through a shroud clouds, I was able to make out a small orange ball in my 80mm, better than nothing.  The orange /red wavelengths cut through the clouds better than the moon that looked like a scattered fuzz with a soft edge.  Somehow I need to fit a proper AM session into my schedule, but it’s clouds all weekend :-(

[Illinois]

Can’t wait to see Mars when it reach 12 “ and larger.  I live in northern that I rather have size 13 or 14 at high sky than size 20 at low sky.  Low sky always poor for my backyard.  Start at 180 power and see if it’s good then go up higher power.  Few good clear night I can see good at around 300 power.  

[jmccown]

I had a look at the God of War early this morning with my 80 mm frac.. Apparent diameter was 9 seconds of angle. The gibbous disk was well-defined but only a hint of albedo features. If we have good seeing in January, should have a good apparition.

[azure1961p]

I guess to You it can appear larger than that, but in reality it can't. Check your facts.

Best regards, Richard

Yes it did appear like that. That's what better optics will do. 

Well, that and good conditions. Largest it can appear is 26.13 arc seconds.  I said it was closer to 30 and I was right.

 

Pete

Edited by azure1961p, 29 October 2024 - 09:49 AM.

[azure1961p]

Oh here's a link you'll need to REFINE YOUR FACTS.

 

https://www.google.c...mobile&ie=UTF-8

[deSitter]

Oh here's a link you'll need to REFINE YOUR FACTS.

 

https://www.google.c...mobile&ie=UTF-8

The largest in modern history was 25.1" in 2003. The largest possible is when the orbits of Earth and Mars are such that Earth's aphelion comes at the same heliocentric ecliptic longitude as Mars' perihelion. But you'll have to wait a very long time for that to obtain, May 4th, 25659, when Mars will be 26.1", just making it to 26". The last time Mars was as close as in 2003 was in -57617 BC and the last time it made it over 26" was in -78957 BC.

 

-drl

[azure1961p]

Thanks for the clarification. And to add to this like the last large apparition a few years ago (not 26.1) had a planet wide obscuring dust storm so we have to factor in God's good humor on these matters which could seriously lengthen the time even more.

 

Pete

[deSitter]

Thanks for the clarification. And to add to this like the last large apparition a few years ago (not 26.1) had a planet wide obscuring dust storm so we have to factor in God's good humor on these matters which could seriously lengthen the time even more.

 

Pete

For those who might be interested -

 

All the planets move on elliptical orbits, and have a closest approach point to the Sun in those orbits - perihelion. An essential orbital parameter, "longitude of the perihelion", changes slowly (over centuries to millennia). The rate of change is unique to the planet, so eventually the longitudes of perihelion of Earth and Mars will be opposed by 180 degrees, and so the Earth's aphelion (farthest from Sun) and Mars' perihelion can match, in which case Mars is as close as possible, and so as large as possible in apparent diameter.

 

-drl

[azure1961p]

Well yes of course.  This is elementary.

 

Pete

[Rick Runcie]

"azure1961p" Pete, I admit I was wrong when I stated Mars could only attain a size of 25.6" in a telescope. As you and deSitter have stated it can theoretically be a little larger at 26.13", for that I apologize and stand corrected.

You are wrong though in your assertion that you were "right". You never stated "It was closer to 30". To quote you directly, you stated;

"Mars isn't going to be too big this time around sadly, but then again, being 30 with a global dust storm was the worst."
"I can deal with a smaller Mars."

I assume you are referencing the global dust storm of 2018 when Mars reached 24.3". So on that point you are wrong, not even close to 30". Which it can never attain.

My main reason for posting earlier was directed more towards novice Mars observers who may not observe Mars often.

To my point, observing Mars while it is still small trains your eye to see features on Mars and become familiar with them so when it eventually reaches its largest size for even an unfavorable opposition they will be easier to see and recognized.

I agree with your point that better optics will make it appear larger. My 6" LZOS refractor allows me to use higher magnifications than my larger aperture scopes in my usual seeing conditions.

Lately though I have blessed with good to excellent seeing conditions. The trade-off is we are in a drought and haven't had rain for over 30 days. It has broken a 150 year record.

Hope you also get favorable seeing conditions for this Mars opposition.

Best regards, Richard

Edited by Rick Runcie, 31 October 2024 - 10:58 AM.

[Cpk133]

Was just checking Sky Safari and it looks like there’s a nice Mars Moon occultation on the night of Jan 13th 2025. Begins at aprox 9:12 pm eastern to 9:13pm so pretty fast and at an elevation of about 41 degrees.  Egress begins at 10:23pm and complete at 10:24 pm at about 52 degrees elevation.  Egress should be a little more interesting as there’s a sliver of shade and maybe some better contrast on the lunar limb.  The odds of it being clear here in MI are probably pretty low but hey, a guy can dream.

[Josephus Miller]

Was just checking Sky Safari and it looks like there’s a nice Mars Moon occultation on the night of Jan 13th 2025. Begins at aprox 9:12 pm eastern to 9:13pm so pretty fast and at an elevation of about 41 degrees. Egress begins at 10:23pm and complete at 10:24 pm at about 52 degrees elevation. Egress should be a little more interesting as there’s a sliver of shade and maybe some better contrast on the lunar limb. The odds of it being clear here in MI are probably pretty low but hey, a guy can dream.

Yes! I saw mention of that in the most recent S&T. I have set a reminder for myself and will observe it if I can.

[ButterFly]

There's a nice map of visible locations at in-the-sky.org: Lunar occultation of Mars

 

It's good to keep an eye on the listings of all events available there: Lunar Occultations

 

As always, ingress and egress depend on your particular location, so check with SkySafari or Stellarium or the like to get the times and location of the limb.

[greedyshark]

Hoping to pull out the RV-8 tonight. 
 

Cs,

Charles

[MrSyzygy]

@ButterFly, @Josephus Miller, @Cpk133,

This event on January 13th will be amazing! Not only does the occultation occur a mere 48 hours before Mars' opposition—where Mars will be at its brightest for the year 2025—but EVERY U.S. STATE (contiguous) will get to see this ENTIRE event—both disappearance and reappearance! This is EXTREMELY RARE for this to happen and I challenge anyone to find anything like this happening at any other point in their lifetime! As a bonus, the entire event happens under dark skies—all before midnight—not in the wee hours of the morning! This will be an exciting night!

But...but...but...but...but! First—on January 4th—Europe gets to have their awesome early evening occultation encounter with a planet—the planet Saturn!

I will post detailed maps of both these events when the time comes—maps that you will only find here on Cloudy Nights!

January will be the most exciting month for lunar occultations for months and months to come! So mark your calendars now!

[ButterFly]

EXTREMELY RARE

And all the clouds heard that!

[deSitter]

@ButterFly, @Josephus Miller, @Cpk133,

This event on January 13th will be amazing! Not only does the occultation occur a mere 48 hours before Mars' opposition—where Mars will be at its brightest for the year 2025—but EVERY U.S. STATE (contiguous) will get to see this ENTIRE event—both disappearance and reappearance! This is EXTREMELY RARE for this to happen and I challenge anyone to find anything like this happening at any other point in their lifetime! As a bonus, the entire event happens under dark skies—all before midnight—not in the wee hours of the morning! This will be an exciting night!

But...but...but...but...but! First—on January 4th—Europe gets to have their awesome early evening occultation encounter with a planet—the planet Saturn!

I will post detailed maps of both these events when the time comes—maps that you will only find here on Cloudy Nights!

January will be the most exciting month for lunar occultations for months and months to come! So mark your calendars now!

Please do keep up the good work. Through sloth or forgetfulness I've missed several big events. I have a project to measure the angular diameter of a star from the occultation light profile. Need a bright one on a dark limb.

 

One of the most memorable sights of my telescoping life was the occultation of Mebsuta (eps Gem) by the tiny 7" Mars, 8th April 1976. Saw it with my wonderful RV-6, may it still be gathering light somewhere.

 

-drl

[thedude_01]

Greeting folks! Very happy to report that we had finally good seeing conditions last night here in Leadville and I braved the 15 degrees temperatures to view Mars. For the first time I was able to see one or two dark spots on the surface with my 9.25 evolution and 12MM and 14MM eyepieces. I wanted to ask, Is the very small white blob on top of the planet the polar ice cap? Both the dark spots and the white spot faded in and out as I was looking at them, but they were clearly. Does Mars have two ice caps you can view or is it just the one?

[deSitter]

Greeting folks! Very happy to report that we had finally good seeing conditions last night here in Leadville and I braved the 15 degrees temperatures to view Mars. For the first time I was able to see one or two dark spots on the surface with my 9.25 evolution and 12MM and 14MM eyepieces. I wanted to ask, Is the very small white blob on top of the planet the polar ice cap? Both the dark spots and the white spot faded in and out as I was looking at them, but they were clearly. Does Mars have two ice caps you can view or is it just the one?

Yes, the ice cap is very large right now because Mars is nearing its aphelion point in its orbit, when it is farthest from the Sun - it is VERY cold and ice clouds will be seen in larger telescopes under good seeing. You want a magnification of 300x or more.

 

-drl

[Dave Mitsky]

I observed Mars with the Naylor Observatory's 17" f/15 classical Cassegrain on Monday morning at 170 and 259x with and without blue and magenta filters but the seeing was poor and I only got very fleeting glimpses of the surface features that were present at the time.

[Cpk133]

Greeting folks! Very happy to report that we had finally good seeing conditions last night here in Leadville and I braved the 15 degrees temperatures to view Mars. For the first time I was able to see one or two dark spots on the surface with my 9.25 evolution and 12MM and 14MM eyepieces. I wanted to ask, Is the very small white blob on top of the planet the polar ice cap? Both the dark spots and the white spot faded in and out as I was looking at them, but they were clearly. Does Mars have two ice caps you can view or is it just the one?

Leadville CO at 9pm local on Dec4 is -7hrs UT or 04:00 Dec 5th. Mars as seen from earth doesn’t change orientation much when viewed at the same time one day apart so the images posted on ALPO Japans Mars section from 11/4 at 4:00 UT (i’m guessing because you didn’t say what time) gives a pretty good idea of what side you may have been viewing.  See images posted by Tomio Akutsu

 

https://alpo-j.sakur...24/m241204z.htm
 

There aren’t any images posted from the 5th yet.  Here’s the link where you can check what others have imaged or sketched.

 

https://alpo-j.sakur...Latest/Mars.htm

Edited by Cpk133, 05 December 2024 - 09:59 PM.

[Rutilus]

Greeting folks! Very happy to report that we had finally good seeing conditions last night here in Leadville and I braved the 15 degrees temperatures to view Mars. For the first time I was able to see one or two dark spots on the surface with my 9.25 evolution and 12MM and 14MM eyepieces. I wanted to ask, Is the very small white blob on top of the planet the polar ice cap? Both the dark spots and the white spot faded in and out as I was looking at them, but they were clearly. Does Mars have two ice caps you can view or is it just the one?

Are we seeing the true North polar ice cap at the moment?  Below is a drawing I made of my last observation on

the 6th Dec. Made with a 6 inch f/8 refractor fitted with bino-viewers. The seeing conditions were only Pickering 4,

but it was possible to see some markings.

 

To me, the white brightening at the North polar region resembled the North polar hood rather than the northern ice cap.  

Of note was a bright yellowish semi-circle extending from the following limb into the disk of Mars.  Was this dust or 

just a very bright western section of the Tharsis region?

 

"Does Mars have two ice caps you can view or is it just the one?"  - Mars does have a Southern polar ice cap,

which can be observed when it is facing us, but at the moment only the Northern polar region is sunlit.

Attached Thumbnails

• 

Edited by Rutilus, 09 December 2024 - 09:09 AM.