Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Techniques for Planets? "Gotta catch 'em all!"

  • Please log in to reply
15 replies to this topic

#1 Sarciness

Sarciness

    Vostok 1

  • -----
  • topic starter
  • Posts: 116
  • Joined: 15 Apr 2021
  • Loc: Suzhou, China

Posted 16 June 2021 - 01:34 AM

Maybe this is a silly question, but do I need different techniques for observing different planets? Should I be learning techniques like averted vision? My understanding is that this is very important for faint objects (increased sensitivity), but will decrease detail seen for brighter objects.

 

So far, I really struggled with atmopheric dispersion for Mercury and Venus, but saw them for the first time last month and it was cool just to see them. They look like bright rainbows and I think an ADC and maybe an ND filter would help?

 

Mars I have seen a few times with naked eye and through my scope but I'm a bit ashamed to say it was a bit underwhelming. I'm mostly looking forward to next year.

 

Saturn and Jupiter are relatively easy and I've seen them many times now (and still haven't got bored- both are awesome).

 

I'd love to see Uranus and Neptune this year and I'm sure I won't see them with naked eye. I plan to locate them using my 8x50 finder, starting next month, and then just observe the same way as Jupiter and Saturn once located.

 

Is there anything else I should be doing in terms of technique?



#2 maroubra_boy

maroubra_boy

    Apollo

  • -----
  • Posts: 1,285
  • Joined: 08 Sep 2009
  • Loc: Sydney, Australia

Posted 18 June 2021 - 04:20 AM

Sarciness,

 

FIRST and foremost is to have the collimation of your scope PERFECT.  This means understanding how to sort out the secondary mirror first before the primary.  This MUST be as good as possible.  If the photons are not all going where they are supposed to then you are immediately losing vital details and contrast.  This goes for all reflector scopes, Newtonians and Cassegrains alike.  While the planets themselves are bright, their details are of low contrast, so you need to be sure that your scope is as well tuned as possible.

 

Second, PATIENCE.  Regardless of seeing conditions, you must slow down and give your eyes time to adjust.  With a 10" Newt/dob you will be able to see an extraordinary amount of detail in Jupiter, Saturn and Mars.  But only if you are patient with yourself.

 

During last year's Mars opposition, using a 9" and a 10" Maksutov, me and a couple of good friends had the most amazing view of Mars any of us have ever had.  Between us we have some 100 years experience in observing, and yet Mars had never appeared like it did that particular night.  Vallis Marineris looked like you could stick your finger into it and run it along its entire length!  But we all had to be patient to give our eyes that little time to adapt first and then BANG!

 

Next comes seeing conditions and elevation of the planets.  To get good seeing it is a game of chance.

 

You can also look at using a couple of colour filters to help bring out certain details.  There is plenty of information on the net about which colour filters help with which planetary details.  What I will say about using filters is PATIENCE!!!!  Many of these details will still be subtle and will require you to be able to identify them.

 

And don't forget the many Moons of the various planets!!!  The Galilean moons in a 7" and larger scope should be able to be resolved into tiny disks.  When they are transiting across Jupiter you will be able to make out colour differences between them, and if everything is perfect (scope, seeing, PATIENCE) very subtle details may even be visible on them.  This will really test your scope and your observing skills!  The moons of Saturn look like little fireflies around the gas giant.  The moons of Uranus and Neptune are more challenging.  And don't forget to have a go at Phobos around Mars.  The trick to seeing Phobos is to keep Mars just outside of the field of view of the eyepiece or make an eyepiece occulting bar in a eyepiece you have <--- see this link.  I saw Phobos for the first time last year as well.  Phobos will really test your observing skills! Eyecrazy.gif

 

Did I mention PATIENCE! scratchhead2.gif brick.gif

 

As your experience increases so will the amount of detail you will be able to pull from the scope smile.gif

 

Alex.


Edited by maroubra_boy, 18 June 2021 - 04:23 AM.

  • Cpk133, JOEinCO, angus63 and 2 others like this

#3 maroubra_boy

maroubra_boy

    Apollo

  • -----
  • Posts: 1,285
  • Joined: 08 Sep 2009
  • Loc: Sydney, Australia

Posted 18 June 2021 - 06:35 PM

Should I be learning techniques like averted vision? My understanding is that this is very important for faint objects (increased sensitivity), but will decrease detail seen for brighter objects.

Averted vision, in a way but not the same way as for DSO's.

 

As I mentioned in my first reply above, while the planets are bright the details are of low contrast.  The thing with low contrast is many details will not jump out.  With Jupiter some of these include white ovals, the lines and markings around the poles, the hue differences inside the Great Red Spot.  With Saturn it is the shade/value differences within the rings and the cloud bands of the planet.  With Mars it is the surface details and the edge of the ice caps.

 

Remember all my bashing of the PATIENCE bit?  Well this is why:  The more you observe and take your time your eyes not only adapt but also your own experience & "micro sensitivity" increases within the central focus of your eyes.  You will not be actually using averted vision - averted vision is for DSO's.  But as your central focus is wider than the size of the planets ever will be in the eyepiece, areas within your central focus will be more and less stunned by the brilliance, more or less saturated by the colours visible, and the nature of how our eyes shift around very quickly will help your eyes pick up very subtle differences in light, colour, tone, etc.

 

Don't be afraid to look up from the eyepiece to give your eye a moment's rest either and then go back to the eyepiece.

 

When it comes to lighting, for the planets I keep my surroundings dark as if I was viewing DSO's.  But I try to limit my use of red light a lot more as red is a colour seen in the planets and I don't want to keep saturating the red colour receptors in the cones of my eyes.  With the Moon there is no dark adaptation to be had, so I keep my surroundings well lit with white light because of this and as a safety thing because the Moon is so bright through the eyepiece - it is not safe to view the Moon with everything dark around your and a feeble red light as you cannot see trip hazards.  But with the planets, dark and limited red light.  NOTE:  This is my own preference with viewing the planets.  You may prefer a different way to illuminate your surroundings and there is nothing wrong with that.

 

From a dark site, Uranus is a naked eye object!  Certainly very dim, but visible.  The quality of transparency is also important.  From the dark site I use transparency is typically excellent and not only is Uranus visible naked eye but dimmer stars are also visible around it.  And with a telescope, Uranus will have a subtle greenish colour to it.

 

Neptune, the trick to identifying it from surrounding stars is it intense blue colour - much too blue to be a star.

 

Venus, well you may see some differences in cloud shading and of course the change in its phase, but that's just about it.  Mercury, now this is a tough customer!  ALL your ducks need to line up of scope and spectacular seeing conditions and good transparency (this includes air pollution).  Mercury is very small to begin with, and it is difficult to see much surface detail on it.  A very difficult challenge to see much at all on Mercury besides differences of phase like Venus.

 

Below is a sketch I did of Jupiter using an 8" SCT and a close up of the sketch.  The letters are for the four Galilean Moons.  A fantastic amount of detail can be seen, but it takes a bit of time, learning and luck with seeing conditions.

 

Alex.

Attached Thumbnails

  • Jupiter, May 5 2018 (2).JPG
  • Jupiter, May 5 2018 (3) LR.JPG

Edited by maroubra_boy, 19 June 2021 - 06:13 PM.

  • dave253, angus63, kas20amc02 and 1 other like this

#4 phillip

phillip

    Apollo

  • -----
  • Posts: 1,066
  • Joined: 26 Nov 2005
  • Loc: Sterling, Illinois

Posted 19 June 2021 - 12:43 AM

Whew, beautiful Sketches!

 

Loads of views the eye adapts for capturing more and more detail.

 

Biggest thing I've noted on planets as already mentioned is the sky conditions. They can change a Ton! My best capture was while doing extensive study on Mars detail, happened to hit an extremely very rare steady sky beyond belief ! So much detail had to review maps even caught Syrtis Minor, note not the famed Syrtis Major. Was peppered with fine markings. Mind blowing. Again takes loads of observations.

 

Very reason for me planets are and always will be my passion. 

 

Clear Sky please, GRS Red Spot and shadow transit just hours from Now! 

 

XT10 Dob

10mm Baader, 8mm Clave, 7mm ortho, 6mm ortho, 5mm ortho, 4.8mm Nagler-barlowed on that rare steady sky, Whew!  


  • maroubra_boy and Sarciness like this

#5 nibiru711

nibiru711

    Explorer 1

  • *****
  • Posts: 84
  • Joined: 03 Mar 2020

Posted 19 June 2021 - 01:36 AM

Try to observe them on as many different nights as possible because every night is going to have different viewing conditions. The amount of air instability is a big factor on what you can see and how high of magnification you can take your telescope on a given night. Last was good but a color filter helped on both Jupiter and Saturn at high magnification. I was able to use a 4mm plossl on both with good results with a yellow filter.


  • maroubra_boy and Sarciness like this

#6 Sarciness

Sarciness

    Vostok 1

  • -----
  • topic starter
  • Posts: 116
  • Joined: 15 Apr 2021
  • Loc: Suzhou, China

Posted 19 June 2021 - 06:23 PM

Thanks for your detailed advice, especially Maroubra Boy. For me, lighting isn't an issue- I don't need any as I can easily see using skyglow :(

 

To summarise I think I should:

1) Get as much time at the eyepiece as possible, partly to learn to train myself to see more detail using "microsensitivity" and partly to increase my chance of getting "lucky" with the atmospheric conditions (seeing, transparency, air pollution)

2) Make sure my collimation is spot-on

3) Try occulting out the planet to see more details on the moons

4) Consider trying coloured filters to see more contast

 



#7 maroubra_boy

maroubra_boy

    Apollo

  • -----
  • Posts: 1,285
  • Joined: 08 Sep 2009
  • Loc: Sydney, Australia

Posted 19 June 2021 - 06:59 PM

3) Try occulting out the planet to see more details on the moons

 

This is for Phobos.  Could be useful with the smaller moons of Saturn too come to think of it! :)  Actually I'll give it a try too this Saturn season waytogo.gif

 

 

4) Consider trying coloured filters to see more contrast

 

Not just "contrast".  Different colour filters can help show specific features a little more easily.  The chart below notes the different sorts of details that different filters can help show.  Some of these features/details can be difficult to pick out even with the use of filters and require you to be able to recognise the feature/detail from the surroundings.  Other features/details will leap out more easily with the use of filters.  And of course other features will be toned down.

 

If you don't want to spend too much money on these filters and would like to have just one, I would suggest the 80A.  Orion sells a kit with the full 20 individual filters in the chart below.  I have this kit and use it extensively, but 20 individual filters is not for everyone.

 

Alex.

Attached Thumbnails

  • 05453_Premium_20-Piece_Filter_Set_inside - Copy.jpg


#8 Redbetter

Redbetter

    Voyager 1

  • *****
  • Posts: 11,151
  • Joined: 16 Feb 2016
  • Loc: Central Valley, CA

Posted 22 June 2021 - 12:01 AM

Phobos and Deimos are only really visible while Mars is quite close from what I have experienced over various oppositions seeing them dozens of times, mostly in the 20".  I don't know what the general minimum apparent size of the planet should be for this, but I suspect it is somewhere in the 20 arc second range for the planet.  (Exceptional conditions might allow considerably smaller, but it gets more difficult.)  The problem with the moons is that they are visually closer to the planet's glare when the planet is more distant.  So even while the planet itself will be dimmed by the distance, so are the moons, while the maximum angular separation is correspondingly less. 

 

The main factor other than proximity of the planet and angular apparent separation from the planet's glare is: seeing.  Once Mars is close enough, Phobos and Deimos are primarily a test of seeing.  If the seeing isn't very good, then even occulting bars do little.  But on the nights seeing is at its best, one doesn't even need an occulting bar.  Occulting bars can only remove veiling glare within the eye--they can't remove the atmospheric scatter around the planet.  Poor or mediocre seeing always seems to coincide with more scatter in my experience, although hazy conditions sometimes coincide with the most stable seeing (so the contrary is not true.)  I have seen both moons with a tired old 8" SCT on a night of excellent seeing, and that was in town through smoke...which reduced radiant losses and stabilized the seeing.

 

The next opposition Mars will only reach about 17 arc seconds, so it will be more of a challenge even for the largest scopes.


  • Voyager 3 and Sarciness like this

#9 Special Ed

Special Ed

    Voyager 1

  • *****
  • Posts: 11,416
  • Joined: 18 May 2003
  • Loc: Greenbrier County, WV 38N, 80W

Posted 22 June 2021 - 10:20 AM

Sarciness,

 

Because you have light pollution at your location you are wise to focus your attention on observing planets.  There is some good advice for you in this thread--here are some additional thoughts.

 

Of all the many factors involved with successfully observing planets, seeing is paramount.  And as mentioned above, cultivate patience.  You will seldom have long stretches of good or excellent seeing (unless you live in certain blessed locations), so you must wait for those moments--often brief moments--when the seeing settles.

 

You mentioned having problems with atmospheric dispersion.  By all means, consider an ADC.  People think only imagers use them, but my experience with one used visually has been very positive.  I've been using one on planets since 2018.  They are useful on objects up to ~60 degrees altitude.  I'm not sure they work as well with newtonian reflectors, though--better research that.

 

Don't feel bad about being underwhelmed by Mars--it has a reputation as the toughest nut to crack.  The key is to start observing Mars early in the apparition and if you can observe it consistently, you will train your eye to see more and more detail.  Use all the magnification on Mars that the seeing will support.  The next apparition will not be very favorable in terms of angular size, but Mars will be at a much higher altitude than it has been.

 

Another tip--try to observe planets when they are at their highest altitude.  Typically that is an hour or so before and after they transit the meridian at your location.  In the case of Mercury and Venus, catch them at their greatest elongation from the Sun.  You will have less problem with the brilliant glare of Venus if you observe it during daylight or early twilight. 

 

Venus is easier to find when the Sun is near or just below the horizon, but I have observed it at midday--just be careful you don't accidentally put the Sun in the FOV.  Place your scope in the shade and block the Sun with a building and you will be OK.

 

Good luck with your observations!


  • payner, maroubra_boy and Sarciness like this

#10 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 98,918
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 22 June 2021 - 08:04 PM

There are a few other tips for observing the planets in the article at https://astronomy.co...rve-the-planets



#11 SDAngler

SDAngler

    Vostok 1

  • -----
  • Posts: 102
  • Joined: 13 Dec 2020
  • Loc: San Diego, CA - USA, Tierra Del Sol when I feel like driving for an hour

Posted 27 June 2021 - 03:07 AM

There are a few other tips for observing the planets in the article at https://astronomy.co...ve-the-planetsĀ 

When I click on this link, I get: 404 Error, Page not found


Edited by SDAngler, 27 June 2021 - 03:07 AM.


#12 Dave Mitsky

Dave Mitsky

    ISS

  • *****
  • Moderators
  • Posts: 98,918
  • Joined: 08 Apr 2002
  • Loc: PA, USA, Planet Earth

Posted 27 June 2021 - 02:05 PM

When I click on this link, I get: 404 Error, Page not found

Unfortunately, glitches sometimes occur when posting links on Cloudy Nights.

 

https://astronomy.co...rve-the-planets

 



#13 Matt Looby

Matt Looby

    Apollo

  • *****
  • Posts: 1,342
  • Joined: 08 Jul 2003
  • Loc: Lake Champlain Valley

Posted 01 July 2021 - 10:37 AM

Keep your eye over the eyepiece, keep both eyes open

and use a black mask for your nonobserving eye such

as take a black piece of sturdy cardboard cut a hole

place it around the diagonal and align it such that the

non-observering eye is looking at the board.

Soon enough, your eyes will mentally merge.

Your can use cloths handkerchiefs whatever.

Never squint never squint.

If the object is painfully bright, use the other eye.

Make sure you breath and relax.

Take 20 minutes for detail to appear and start recording that info on to paper.

 

Jupiter requires strip sketching.


  • kjkrum and Sarciness like this

#14 mikerepp

mikerepp

    Surveyor 1

  • -----
  • Posts: 1,529
  • Joined: 04 Aug 2014
  • Loc: Harwood Heights, Illinois, dark site Manistique, Michigan in UP

Posted 02 July 2021 - 06:24 AM

 

Jupiter requires strip sketching.

You view Jupiter in the nude?  lol.gif



#15 Notdarkenough

Notdarkenough

    Ranger 4

  • *****
  • Posts: 330
  • Joined: 17 Jan 2021
  • Loc: 4700' ft elevation at 41Ā°

Posted 02 July 2021 - 06:58 AM

You view Jupiter in the nude?  lol.gif

Please, no 'astrophotography' of that!



#16 dweller25

dweller25

    Vanguard

  • *****
  • Posts: 2,317
  • Joined: 30 Aug 2007
  • Loc: Lancashire, UK

Posted 02 July 2021 - 04:15 PM

I find binoviewers help a lot when observing the planets.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics