Which of these is visible from Earth?

[TheDreamStone]

Which planets or moons of our solar system are visible from Earth?

[pvaz]

All planets and some moons. But it really depends on what degree of visibility you expect.

This is what you can see:

Mercury and Venus: You can see a faze, just like our moon. They're always trailing the sun from our perspective, they have a smaller orbit, so you can see them either right after sunset or right before sunrise depending of what side of the sun they are at. For that reason you see part of the day side and part of the night side.

Mars, Jupiter, Saturn: You can see a disk resolving and surface detail. You can see the rings of Saturn and some bands, on Mars you see the polar cap and some darker features on the surface on Jupiter you can see bands, festoons and the great red spot, when they are facing us. You can also see the moons on jupiter/saturn, they show like steady bright dots in a line. Mars needs at least 200x for surface detail. Jupiter and Saturn look good at 100x.

Uranus, Neptune: They are too far away. You see them as points, like stars with a bluish/greenish hue.

Don't expect hubble pictures! They are tiny even at high mags, still they always leave a memory and being able to actually see them with your own eyes is a great feeling.

[TheDreamStone]

Thanks

[LukeSkywatcher]

Observing planets is great. They are so amazing. Even if you cant see detail on the surface or cloud layers..................they ARE all a very distinctive disk that do not tend shimmer or twinkle. Saturn (when its rings are open) is perhaps the apex of planetary observing. It will simply leave you gobsmacked.

Jupiter is another "WOW" planet..........great upclose when you see the banding around it, but to ME the best views of Jupiter are done with a 15mm,32mm eyepiece where you can see the planet itself and its 4 main moons lined up around it. STUNNING.

I've never had any luck with Mars. So i can take it or leave it.

Neptune and Uranus i have never seen through a scope but the distinct colours they give off are beautiful. As said above they appear like stars cuz they are so far away.

Mecury and Venus are lovely to see with the naked eye. Never observed them in a scope.

Pluto (i am so old school that Pluto is and always will be a planet to me) i have never seen apart from in pictures.

I dont care much for these newly discovered planets,dwarf planets such as Eris,Ceres etc. In my mind they are nothing but asteroids.

[TheDreamStone]

Thanks ... and may the force be with you!

[LukeSkywatcher]

I wish the force was strong enough within me to part these damn clouds.

[Doc]

It depends on many conditions, amoung these are seeing, transparancy, and of course your telescopes. With 16" of aperture I've seen 8 moons of Saturn and Uranus's moons. But even with a modest scope you should see Venus's phases, and Mars's polar caps.

[TheDreamStone]

lol @ Luke

[superjody]

what can i expect to see of mars with my skywatcher explorer 130???

i only have the standard lenses at the mo, 10, 25 and x2 barlow.

so far i have been amazed by the moon, seen jupiter alot and 4 moons(only little bright dots) with a little detail of the planet, orions nebular is also a fave of mine but should i be seeing more than just a little blue haze around it?

p.s......if you aint already guessed, im pretty new to this ha ha

[pvaz]

For Mars you should expect a very small disk. You should try and use the barlow and the 10mm for 180x on your scope. If the quality is not good then use the 10mm alone.

With that mag, under good seeing conditions, you should expect to see a white area on the north pole (will be the bottom due to inverted image) and some darker features on the surface. The amount of dark features will depend on what side is facing us. Some parts of the planet are pretty dull.

Due to it's small size you need to spend some time looking at it and let your eye adapt. Doing a rough sketch will help you notice the tiny details.

I also must say I see much more sharpness and better light scatering control with an ortho 5mm EP. My 10mm + barlow creates too much light scater around it and blurs the image a bit, enough to make it very hard to notice the dark features, the pole is easy to identify even with these.

Best time to see it will be around Jan 20th 2010 when it's closer to the Earth. It won't be this close for another 3 years. Right now, it's already close enough for a good view.

I scaled the attached image to mimic what I see at 240x on a good seeing night. When you are looking you get "pockets of seeing": the image gets sharp for a bit, then seams out of focus, then sharp again... Thats the atmosphere interfering.

PS-> I'm using a 1440x900 resolution on a 17" wide screen and it looks the same size as in the scope when looking at the monitor from about a 1-2 meters distance. The image attached will appear bigger/smaller on different resolution settings and other monitor sizes.

[superjody]

cheers pvaz, il keep an eye out for it and see what i can come up with.

does your ortho 5mm get you in closer for a better view? im not too sure on how eyepieces fully work yet, all i know about mine is that the 10 mm gets me alot closer than the 25mm but the barlow can give some false colour around the edges on certain things

[pvaz]

If you divide the scope focal length by the eyepiece focal length you get the magnification.

Example, your scope haves 900mm focal length so:

with the 25mm: 900/25 = 36x

with the 10mm: 900/10 = 90x

Adding the barlow doubles it.

I get 240x using the 5mm EP on my scope (1200/5). I find Mars needs around 200x to show details. The Orthoscopic (ortho) is a design of EPs used by several brands. They have a very short Field of View (almost seams like your peeking through a straw) and a short eye relief (you have to get your eye really close to the EP and it makes it impossible to ware glasses with this EPs) but the design improves contrast very well so it's ideal for planetary observation, which highly makes up for all the other shortcomings of this design.

[superjody]

mine is the 650mm scope so il get a little less magnification

25mm:650/25 = 26

10mm: 650/10 + 65

so would i be better off getting a smaller eyepiece and maybe a x3 or 4 barlow lens?

[pvaz]

mine is the 650mm scope so il get a little less magnification

25mm:650/25 = 26

10mm: 650/10 + 65

so would i be better off getting a smaller eyepiece and maybe a x3 or 4 barlow lens?

Yeah, but you should keep under 250x. Your scope is a 5" aperture and thats about the max it can provide without image smoothing due to lack of resolution.

Also you need to know that for all other objects, other then planets and the moon, high magnifications won't do you any good (most are very faint but large in area) and that using high magnifications is highly dependent on seeing conditions.

Still planets give the best wow factor in the hobby and having the gear to provide a mag around 100x for average seeing conditions, and another around 200x for good seeing conditions is well worth it.

[superjody]

think i might invest in a x3 barlow and a good smaller eyepiece

cheers

[superjody]

would a CELESTRON 6mm PLOSSL be any good? seen it for £12.99, i know thats bottom end price or is it worth spending more??

[LukeSkywatcher]

The Celestron Plossls I THINK are pretty good. Mind you i can only compare then to the standard non-descript EPs that come with most scopes. Most seasoned astronomers wouldnt give the Celestrons a second glance.

IF you can afford to spend a bit more, then a better quality EP would be the right choice.

Personally i never use any EP lower then 10mm with my Celestron scope because the higher magnification pushes the scope beyond its comfort zone. I'll be interested to see how my Celestron Plossls and 2X barlow perfom with my new 130mm scope. I hopefully wont have to upgrade my EPs for the new scope but there is no point in having a scope with superior optics compared to the 90mm scope and using the same low(ish) quality EPs. Maybe the same EPs will perform better with the better optics.