How do I locate planets using a telescope?

Question

I figure that the easiest things to see other than the moon would be Mars, Venus, Saturn, and the other planets. This week Saturn is supposed to be stationary so I figured it would be easy to spot, but trying to locate one dot out of all the ones in the sky is difficult, even when they try and narrow it down by showing you the constellation it's near.

I tried adjusting my lens when I was able to get a star in the viewpoint, but when I put it in focus it didn't really get any bigger. Just seemed like a dot.

I couldn't find Saturn by its rings and even tried using binoculars to see it first, but wonder if I'm wasting my time with this thing. Not sure how zoomed in it will even look through a hobby telescope. Shouldn't Jupiter, Saturn, and Venus be very visible to a telescope? I'd like to maybe see a crater on Mars or at least the red surface.

My D is 115mm and F is 900mm. Is this good?

Answer 1

Back in the day I'd have said learn the constellations and work out which of those dots is a planet. You can download programs like Cartes Du Ciel and Stellarium which will show you the night sky for your location and help you find the planets.



Now, with a smartphone, you can download an app which will do it all for you. I like Skeye (you can use it as a "push to" finder on your 'scope) and Mobile Observatory (not free, but very useful).



It's possible that you've correctly identified the planet but you're pointing the 'scope in the wrong direction - make sure your finnder and main 'scopes are collimated i.e. they're both pointing at the same spot. It's best to do this in daylight by lining up on things like TV aerials.



"My D is 115mm and F is 900mm. Is this good?"

It depends - it's at the bottom end of useful. There are some nice 'scopes of that size but there are a lot of toys, too! If you were able to focus on a star and get a dot (rather than a blob or a comma) you're in with a chance!

Answer 2

Saturn is brighter than stars and barely faintly yellow. You can go to Astronomy.com or Sky and Telescope.com and they both have an observing section and if Saturn is out during the week, they usually show it's direction. Saturn is visible in the south, southeast or southwest in the evening time right now. Saturn will be one of the brightest, if not the brightest light in that general direction in the evening time and you can easily point a telescope to it as a result. Any telescope, with even a low magnification and focused clearly, should easily see Saturn and it's rings.



You can also download programs for planet location. If you buy an Orion telescope, it often even comes with Starry Night software which will show you where planets are with your time, date and location.

Answer 3

Nothing wrong with your telescope. You sweep your telescope to an ordinary star, not Saturn. Just try it again carefully. Even with the lowest magnification Saturn will be no longer a dot, but a disk, even it still will be small, but you also will already notice a kind of rings. Higher magnification then displays the disk bigger, but also less sharper, so you will choose the best situation.



Mars is small itself, so don't expect a big disk with clear craters. Experience is needed, maybe with filters, for even seeing just some darker spots on the surface.



Mercury and Venus only show displays just like our moon, with phases, but very smaller of course.

Neptune and Uranus only show small disks while very high magnification is needed.

But Jupiter also is a nice view, the 4 moons obviously, and 2 horizontal belts on the surface.

Answer 4

Indeed identifying individual stars and planets is difficult when you start out. You need to get some practice. Step away from the scope for a bit and just try and match up the stars in the sky with the dots on your map; you'll probably find the constellations look bigger than you expected. If you pick up an up-to-date astronomy magazine they usually include a star map for the month including the planets.

Answer 5

It depends on the type of mount you have. Some telescopes come with a "polar mount" which is marked in degrees. You point the top of the mount at Polaris and then you use pan and tilt controls to point at a position in the sky. You get the position from a ephemeris or nautical almanac. The other type of mount is a simple tripod. With a simple tripod, you have to point and shoot, since it has no calibrated markings. Most telescopes have a "finder scope" aligned with the axis of the telescope. The finder is a wide field scope with cross-hairs. You use the finder scope and a star map to locate reference stars which you use like landmarks to get your bearings and find the object you seek. You then center the star or planet in the cross-hairs of the finder scope and it then should be in the field of view of the main telescope. I have a 4" reflector telescope with a finder scope and I can barely see Saturn, but it is there. To my small low cost, low quality 4" Newtonian reflector, Saturn is a fuzzy disk. My scope is too small to resolve the rings, hence the blur. Get a star map that is accurate and up to date, find the landmark stars and then look around. If you need to use light, use dim red only, or you will lose your night vision and it can take as long as 30 minutes to get it back again. I use a large red LED as my light source. I replaced a white LED with a red one in a small single LED flashlight I picked up at a $1 store. It works very well to illuminate a star map enough so I can make out the landmarks I need.

Answer 6

A planisphere is very helpful.

http://en.wikipedia.org/wiki/Planisphere

Locate the constellation of Scorpius and the star Antares. Saturn and Mars are visible to the naked eye. The reddish dot is Mars.

http://www.starrytrails.com/starry_trails_archive/starry_trails_july_2014.pdf