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Jan
11
revised How did scientists determine an estimate of the number of planets greater than Sedna's size to exist in the Inner Oort Cloud?
Add reference.
Jan
11
comment How did scientists determine an estimate of the number of planets greater than Sedna's size to exist in the Inner Oort Cloud?
I hope you don't mind that I've edited in a reference. I had no idea who Mike Brown is and it is hard to Google for as there is a current news item about an unrelated man with the same name.
Jan
11
suggested approved edit on How did scientists determine an estimate of the number of planets greater than Sedna's size to exist in the Inner Oort Cloud?
Jan
4
comment How is the diameter of a gas giant calculated?
Related: Why is Jupiter so sharply defined?.
Jan
4
answered Calculating area of visible sky
Dec
31
answered How to see Saturn's rings through a pair of binoculars?
Dec
28
revised What to look for in a tripod for binoculars?
added 130 characters in body
Dec
24
revised What to look for in a tripod for binoculars?
Add link
Dec
24
revised What should I look for in an astronomy tripod?
added 91 characters in body
Dec
24
revised What to look for in a tripod for binoculars?
added 91 characters in body
Dec
22
answered What to look for in a tripod for binoculars?
Dec
20
comment Stable polar solar orbit with the Earth continuously observable
@Neomada: Noordung's edit makes your question more appealing to snobs like me who are more likely to read a question that is properly formatted than one which isn't. You should be thanking him, not insinuating that his motives were cynical.
Dec
20
comment If the moon wasn't receding from Earth, what would be the impact on the weather and tides?
The energy of the sound of waves crashing comes from the moon. I am going to mention this to my daughters next time we are at the beach with the moon visible. Thank you for this wonderful insight.
Dec
20
answered Smallest body that can be observed from Earth?
Dec
20
answered Can Jupiter's bands be made out using a 15x70 pair of binoculars?
Dec
13
comment Why, in the Solar System, all the mass seems to be concentrated at the centre?
@RobJeffries: Thank you for mentioning the situation with Vega. I do believe that a few years ago it was thought that the disk is protoplanetary. I should read more, science progresses!
Dec
13
comment Why, in the Solar System, all the mass seems to be concentrated at the centre?
I mentioned that "Not much matter can form a stable orbit there" and you might notice that 97% of the mass of the solar system is not found there!
Dec
13
comment Why, in the Solar System, all the mass seems to be concentrated at the centre?
I don't have any idea, but I should imagine (warning: speculation following) that there is more of a continuum than a cutoff point. A dust particle may be perturbed by a passing Theia and thus be ejected by gravitational slingshot. However, two fist-sized objects would interact in a more uniform fashion and neither would have enough momentum to eject the other. I don't believe that we have the technology to observed this in nature yet, nor do we have the technology to perform Monte Carlo planet-formation experiments just yet.
Dec
13
comment Why, in the Solar System, all the mass seems to be concentrated at the centre?
@HDE226868: From what I understand, during the early stages of planetary formation (such as that which Vega is undergoing right now) things are too chaotic (i.e. too many random gravitational encounters and collisions) to really have a stable orbit for any accretions of matter without significant mass. I'm not sure how long this stage lasts, but I do believe that we can observe it for quite a few stars (such as the afore-mentioned Vega). So the accretions of matter which have not-significant mass are constantly having their orbits perturbed.
Dec
13
comment Why, in the Solar System, all the mass seems to be concentrated at the centre?
Nice answer, but I feel that you stop right where it gets interesting! I pick up where you left off in another answer. If you feel that this should be a single answer you can edit my answer into yours.