Planets looks like normal stars when I see them using telescope

Question

I've been trying to see planets using my 114 mm (aperture) f=900 mm telescope. For the moon, I got very good quality pictures, but when I try to see planets they just appear to be as if I'm looking at a star with my naked eye; it's just a point of light.

I tried looking at Saturn, and it appeared the same. I couldn't even get a light blur or suggestion of its rings.

I tried looking at Jupiter which is quite bright with the naked eye, but couldn't see any of its moons and neither got any indication of its disk. It's like as if I'm looking at it with the naked eye only.

I used both a 25 mm and 10 mm eyepiece, but both went in vain.

I used the Stellarium app to make sure I'm pointing at correct object.

Answer 1

I'm a VERY amateur observer myself and my telescope has the exact same aperture as yours. I can all but guarantee that you should definitely be able to see Saturn rings and Jupiter moons (and even some planet bands) through your scope. It's virtually impossible NOT to see those features, actually.

The only "diagnosis" I can think of, barring a hardware defect, is that you're not really looking at the planets. Are you 100% sure you're aiming the telescope exactly where the planets are? Planets are surprisingly difficult to target, due to the small FOV you get when using a telescope. (This, BTW, is why many enthusiasts give up on their telescopes after a few unsuccessful attempts at seeing a planet).

If your telescope doesn't have a guidance system, I'd recommend using a laser pointer (and a good friend) to point at the planet while you look through the eyepiece, tracking the laser trail until you find the planet.

If your telescope does have guidance, then perhaps it needs to be (re)calibrated.

Also as @MikeG suggests, if you telescope has a finder scope, it's really worth your while to take some time to align the finder to the main telescope, perhaps using an object on the horizon during the day, or the Moon. But don't use a star or planet.

Then using the finder scope first to point directly at the planet you are much more likely to have the planet already within your 36x field of view, or worst case need only a very small, much more restricted search.

Please try again and let me know if you need any more help. Don't give up. It will be worth it when you get to see the planets.

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Example of what using an object near the horizon during the day to align the finder scope to the main telescope might be like:

Source: Wikimedia

Answer 2

With f=900 mm and a 25 and 10 mm eyepieces you would be viewing at 36x and 72x.

36x is a very reasonable magnification under any condition, and 72x can probably still be considered "useful magnification" at least under good conditions.

I don't have particularly good eyesight but I can assure you that in my 8x42 binoculars (only 8x magnification, 42 mm aperture) I can resolve all four Galilean moons of Jupiter (if they're far enough away) and the two little bumps on the side of Saturn where its rings extend.

I last did this last summer when they were at opposition.

Now, here's some potential kickers; sometimes Galilean moons may be very hard to resolve because they are behind Jupiter, or in its shadow (eclipsed) or simply too close to Jupiter's bright disk (or occasionally eclipsing each other!)

• When will the next series of mutual eclipses of Jupiter's moons begin?

And sometimes Saturn's rings are so close to edge-on that they are difficult to see.

If you have the date and time that you looked at Jupiter it should be pretty easy to find a website or ephemeris that shows how far the Galilean moons were from Jupiter to see if you just chose an unfortunate time to look.

But for Saturn you really really should have been able to clearly resolve those rings. Here is a set of simulated images of the planet at each time Saturn is at opposition, meaning that it's a bit closer than average and up most of the night. It shows the slowly rotating pattern varying with Saturn's orbital period of about 29.6 years; the last image is almost the same as the first image.

If you looked in 2022 with the instrument and eyepiece you describe, you certainly should have seen Saturn's rings.

This sequence of simulated views demonstrates the 29.5-year orbital period of Saturn by opposition date, as well as the dramatic changes in the orientation of the planet's ring disk. The ring system revolves around a fixed axis, so both sides of the ring disk are visible from Earth during each period in which Saturn orbits the Sun.

Reference: Meeus, Jean (1988) Astronomical Formulae for Calculators (4th ed.), Willmann-Bell

Source: Wikimedia Commons

This is an animation of the 28 images of Saturn shown in Saturnoppositions.jpg (simulated views using a computer program written by Tom Ruen). This animation demonstrates the 29.5-year orbital period of Saturn by opposition date, as well as the dramatic changes in the orientation of the planet's ring disk. The ring system revolves around a fixed axis, so both sides of the ring disk are visible from Earth during each period in which Saturn orbits the Sun. (See source file for more info and references.)

Source: Wikimedia Commons

Answer 3

I second the other answers that you should be able to see moons of Jupiter (at least one should always be visible) and the rings of Saturn. I've had similar (just larger and smaller) equipment, and on a really good night you should even be able to see the main bands of Jupiter.

The other commenters make really good points about aiming your telescope. But supposing that your aiming is correct, there are some other things that could be going on:

• Planets are tiny. It takes something like Hubble to see Saturn like in Uhoh's post. Especially with small equipment like ours we will only see a tiny image. To make sure I am looking at the right thing I consult a star-chart and (Jupiter) look for the line of moons (Saturn) look for the oblong spot.
• Your focus may be off. You may already know this but for ideal seeing I usually say that you want to adjust the focuser to make a bright star appear as small as possible. With most bright stars I can see lots of faint background stars when I get the focus right.
• Something may be preventing you from getting a good focus. For me this has been things like a smudge on my lens, dew on my mirror, or (most commonly) bad collimation. Your mirrors/lenses need to be in a precise alignment to see details. If you have tried everything else a bit of a collimation check may be in order. How you go about that depends on your scope. (Astronomy SE is littered with help.)

If you get all of that just right, you will certainly be able to see the small gap between Saturn and the rings. Tickled me pink when I got my first scope working well enough for it.

Answer 4

I am myself an amateur stargazer equipped with a Celestron Astromater 130EQ having an aperture of 130mm, focal length of 650mm and focal ratio of f/5.
I have had a glance at all the planets of the solar system alongwith several nebulas and galaxies. Using a 10mm eyepiece and my telescope pointed to Jupiter, I can clearly see a smear of brown color over the planet, accompanied by three of its moons: Io, Europa, Ganymede, and Callisto. Your telescope must have almost the same capability, so you should at-least expect to see 2 of its moons clearly.
As for Saturn, the rings must be visible.