Planets Definition and 515 Threads

This might seem like a silly question to most of you but I’m going to ask it anyway. Why do all the planets orbit the sun?

http://www.ucolick.org/general/pressrelease/99/99-11-29.html The orbits of the new planets, like those of most of the extrasolar planets discovered so far, tend to be quite eccentric, tracing paths that are oval rather than circular. One of the planets, around a star called HD 222582, has...

? (lol)

Hi guys, Just a question if anyone has any insight to offer in theh notion that the planets of our solar system are some how counter balanced by "Phantom" plane on their opposite side of the sun? I heard some where of this? but it was along time ago If you have what are your thoughts on...

How do we find out the gravity of planets

What are the influences of planets on other planets ? As far as I'm concerned I know about the gravitational influence For example the coming close of Mars near Earth

[SOLVED] Weight of planets Does the weight of planets depend upon the speed of the planet and gravity ?

massive compact halo objects have been detected by microlensing an invisible compact object passing in front of a distant source causes a temporary spike in the light curve by gravitational lensing---the brightening might last a couple of days this was written about in the late 1990s when...

http://www.newscientist.com/news/news.jsp?id=ns99994172

I was just playing with this little doo-hickey http://www.phy.ntnu.edu.tw/java/circularMotion/circular3D_e.html and was wondering; How is it that Jupiter and Neptune remain in orbit even as large as they are? Is it their mass and that the Suns gravity has THAT much of an influence on them?

http://arxiv.org/abs/astro-ph/0209383 "Much indirect evidence suggests that wet, rocky planets are common." fairly recent article by Lineweaver (September 2002)

If the sun becomes a black hole, all the planets in the solar system will stil be orbiting the sun as usual, but would there be any alteration in their orbit trajectories? And would the gravitational influence be stronger on the planets? If so, what is the relationship between the density of...

Two questions: 1) When in 2004 is the Cassini probe due to reach Saturn/Titan ? 2) Are there any missions being planned or that have been proposed (cost permitting :wink:) to any of the three outer planets (Uranus, Neptune and Pluto) in the not too distant future?

Browsing through my physics book... The book defines velocity as the limit(t->0) [Δx/Δt], which of course makes sense. An acceleration can occur in two ways: either the speed (speed= ||v||) changes or the direction of the velocity changes. Centripetal acceleration (||a|| is...

I've just talked with someone who informed me of a T.V. special, that dealt with the discovery of two planets, that move in perpendicular orbits - relative to the other nine planets. Is this true, or was I right in assuming that it was ridiculous?