All Questions
Tagged with amateur-observing solar-system
8 questions
3
votes
1
answer
162
views
How to show that a complete revolution of Earth around the sun takes 365 1/4 days?
Seasons change regularly and day and nights also.
The fact that Earth takes 365 1/4 days to complete one complete revolution was found a long way back in history, but so far I can't find any current ...
- 41
1
vote
1
answer
295
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I saw a weird thing around Venus
I pointed my telescope
(50mm aperture, 500mm focal length, 4mm eyepiece, image taken through a window)
at Venus and saw this:
What is it? I don't think this is Uranus or Neptune as my telescope is ...
user35183
3
votes
1
answer
496
views
Has a near earth object in heliocentric orbit ever been bright enough to be visible to the unaided eye?
The question Can we see asteroid 1998 OR2 with unaided eye? got me thinking. Space.com's Vesta: Facts About the Brightest Asteroid says:
Vesta is the second most massive body in the asteroid belt, ...
- 30.7k
5
votes
1
answer
2k
views
What does the Sun look like from Eris at its aphelion?
At its aphelion (most distant location from the Sun) the outermost-known planet Eris is about 100 times as far from the Sun as Earth. What does the Sun look like from Eris' surface? Is there still a ...
- 1,262
4
votes
1
answer
82
views
Will comet 21P that just passed Earth on Sept 10 produce Draconid storm on Oct 9?
Comet 21P/Giaccobini-Zinner just made its closest pass to Earth and also made its Solar perihelion on the same day (Sept 10) which is roughly one month ahead of the annual Draconids meteor shower (Oct ...
- 250
28
votes
2
answers
157k
views
How much magnification is needed to see the planets of solar system?
I have a 3inch Newtonian reflector telescope with 300 mm focal length. I can use highest magnification of 75x using a 4mm eyepiece. But in 75x I can't see the details of Jupiter what was expected. ...
- 501
2
votes
5
answers
6k
views
Why can't I see Mars clearly?
I just bought my first telescope - a Celestron CDC 1100. It came with a 40mm lens so with a primary focal length of 2800mm the power should be 70x.
My problem is that I've looked at Sirius and Mars ...
- 483
8
votes
1
answer
7k
views
Are Barlow lenses stackable for bright objects?
I'm back to the refractor that I own, and I want to maximize the zoom capacity. I realized today that I own more than one barlow lens, and I was wondering if I could stack them together for looking at ...
- 2,033