Planets Definition and 510 Threads

why should the planets rotate?

My son asked me "what is the maximum size a planet can reach". I told him that it depends on its constituents; If it is a gas planet or a solid planet. Can someone answer this question for me?

In case Mars jumps from it's orbit to earth's,then will it lose it's energy in electromagnetic radiation form or something else happens? I found from Doc AL that only charged particle loses energy in electromagnetic form.Then in which form will it lose it?

Homework Statement Basically I don't understand how you do this - the course I'm doing keeps mentioning the orbital radius of extrasolar planets but doesn't tell you HOW to find it? Can anyone please help - in plain English, please, I'm not a natural scientist! Homework Equations...

Hi there. As a molecular biologist my knowledge of physics is fairly limited to the topics I learned before college, but recently I have developed an interest in learning a bit more about it. More to the point a certain question has been puzzling me for some time now and I was wondering if...

HD 10180 star system [/Color] Reference: http://en.wikipedia.org/wiki/HD_10180" http://en.wikipedia.org/wiki/55_Cancri" http://www.youtube.com/watch?v=r96nO0qoLUU&feature=player_embedded"

On August 26, 2010, scientists announced the discovery of two planets orbiting around Kepler-9. Kepler-9 b - 0.252 MJ - 0.14 AU - 19.24 days Kepler-9 c - 0.171 MJ - 0.225 AU - 38.91 days [/Color] Reference: http://en.wikipedia.org/wiki/Kepler-9"

Hy. What makes the planets to keep their position on the orbit (the same orbit). Shouldn't be attracted by the gravitation of the star ? Thanks!

Hy. I was wondering if the gravitation is too much on earth. What if on some other planets is less. How that affect life ?

Hi, Is there a link between how fast a planet rotates, and the strength of its magnetic field? Or is there any recent work on this? I know that neutron stars rotate very fast and have v strong magnetic fields, and the same with Jupiter Okay, so that's not much to go on, but... is...

Hello, I was just curious why do all of the planets in the solar system orbit in approximately the same plane? Why is it not random? This is not a homework question, but if possible I would like to see the math that accompanies the explanation. thanks

Venus, Mars and Saturn are converging on the Constellation Leo at the end of the month. I would like to find the Right Ascension and Declination of these planets given the obliquity, the true anomaly, the radius from the sun and the inclination.

First question: "The planets spin in the same direction they orbit". What does that mean?: A roulette ball (when rotating inside the roulette) spins in the same direction it orbits, or in the opposite direction it orbits?

for ease of explanation, imagine that the barycenter of two planets is the center of a wheel and that the planets revolve around the edges of the tire. the center of the tire (barycenter) is in orbit around sun, as if the wheel is rolling around in its orbit. my question is, is this possible? of...

Hey, I'm a programmer with a strong grasp of maths and wish to verify the existence of extrasolar planets. I assume they just use basic Newtonian physics. Where can I download a dataset which has confirmed extrasolar planets so I can replicate the method they use to find them? What method...

[b]1. The table below lists the average distance from each planet to the Sun and the time each planet takes to make a complete orbit around the Sun (“Orbital period”). The orbits of all of the planets are roughly circular. Your job is to determine a relationship between the radius r of a...

A year ago a friend of mine told me that have seen a film that claims that it seems that the planets in not exactly where we believe these to be. When space probes arrive there are small deviations. Is that really true? Where can I get more info?

do all planets have magnetospheres?

Hy. I was wondering what is the energy of the planets (in our galaxy)? How it is called ? frequency ? i don't know. And how that is produced ? Thanks !

Why do starts blink and planets do not. There are some stars that are just as bright as a planet(unless my observation is wrong). I know the light from the star enters Earth's atmosphere and due to the variation in density(which means change in dielectric constant of the medium in which light...

Please help me with this question. Thanks

I am writing a science fiction story about a strange universe. I have a few questions which fall in the same general category. 1) What sort of gravity would allow a planet to maintain the shape of a dodecahedron? 2) If there exists a planet, where the physical laws are the same as in this...

If the universe is infinite, are there planets made out of swiss cheese?

"Pure" planets? What is the likelihood of a planet being almost entirely one element? Is it possible to have a planet that is purely water?

Where, or how can I find out what the Orbital state vectors of all planets and possibly dwarf planets are at a certain point in time (in our solar system)? Thankyou in advance.

Why do the stars blink, but the planets do not? I need good explanation, please!

I'm playing devil's advocate here. Why are we bothering with extrasolar planets? (Kepler mission) Why is it so important that we find other earthlike planets? What's motivating NASA to find signs of life elsewhere (Fermi's paradox)? -ac

Happy New Year Everyone! Anyways, I have an interesting question. I have no background on astronomy, but came across some of it while studying for AP Physic C - Mechanics, where it covers Kepler's law and such. Although this was random, I wondered about this: If there are a lot of planets...

I saw a film some time ago at NGC. It was told that the planets not are exactly there where expect them to be, when space probes arrives, but I did not got the point.. What is wrong ?

1. Basically it tells me that Mars has a mass of 8*10^23kg.Phobos, its closest moon, whips around planet in 7 hrs. How far from Mars is Phobos? I got that m=8*10^23 and T= 7 hrs . I am pretty sure i need to find the radius. my only problem is that I can't find the formula where i can...

If you were to measure the area of a sector that a planet would sweep out in one week around the sun. It would be the same no matter what time of the year it was. What conservation principle is this example demonstrating? Linear, angular or both? and why?

Homework Statement On Planet Plutnik the acceleration due to gravtiy is not 9.8m/s^2. An object dropped is found to fall the final 15m of its trip in 2seconds. It lands with a speed of 10m/s. Find the acceleration due to gravity on Planet Plutnik. Homework Equations d = vit + 1/2at^2...

Planet A: Mass - 8 × 10^24 kg, Radius 8,200 km, Temperature - 500 K, Semi-major axis - 0.52 AU Planet B: Mass - 3 × 10^27 kg, Radius - 57000 km, Temperature - 150 K, Semi-major axis - 6.4 AU Planet C: Mass - 6 × 10^23 kg, Radius - 3500 km, Temperature - 105 K, Semi-major axis -37.8 AU 1. If the...

Hi guys, I'm not sure if this topic fits here, but can anyone tell me about the origin of planets? Like how is our planet formed?

I've read that a planet's rotation around it's star is in the same direction has the rotation of the star on itself, is that true? If so, why? Does it have something to do with the conservation of angular momentum?. And another question (well, two :P) : why do stars rotate (the outer layer, I...

Planets <--> solar systems <--> galaxies Have planets been observed outside of solar systems, or solar systems outside of galaxies?

I was looking at this link: http://en.wikipedia.org/wiki/File:Universe_Reference_Map_%28Location%29_001.jpeg" and wondered to myself why the asteroid belt just outside of Mars is a ring...as opposed to a sphere. Then I thought, why do all the planets seem to orbit the sun on a similar plane...

Hi everyone ! I am doing a report of some papers on extrasolar planets and I would like to clarify some points! 1) What is the difference between oberving in the IR at 4microns or 24microns ? what do you get in difference in observation ? 2)how can a measure of flux decrement can affect...

Homework Statement I want to try to find the scale height of a planet using H=kT/Mg, where H is the scale height, k is the Boltzman constant, T is the surface temperature, g is the acceleration of gravity, and M is the mean molecular mass. I am having a great deal of trouble understanding...

Was thinking about the solar system and came to this question to which I cannot figure out a simple, definite answer. Maybe something having to do the elements that compose the planets?

The title states it all.

Homework Statement Part 1) The centers of a 21.2 kg lead ball and a 442 g lead ball are separated by 10.38 cm. What gravitational force does each exert on the other? Part 2) What is the ratio of this gravitational force to the weight of the 442 g ball? The Attempt at a Solution I...

Can I see anything other than the planets with a 4" telescope? I saw Jupiter (and four of its moons), Neptune, Mars and Venus but they were all really tiny so I was wondering if the planets are so tiny does that mean I wouldn't be able to see any of the other objects, like galaxies and nebulae...

consider two planets, planet X and planet Y with masses, Mx and My separated with distance, D and they orbits about the centre of mass of the system which remains stationary. we know that period of orbit for X and Y are the same because they are always collinear with the centre of mass...

Hi again :) I need some help in a not difficult question (I hope). I would like to know how other planets can interfere in the system Earth-Moon - I suppose it is mainly gravitational force acting. However, is this interaction from other planets big enough to cause changes in the route of...

Hi,everyone! i have a few queries about various concepts of physics. 4 d beginning,gravitational force is an attractive force.It increases as the distance decreases. Then,why don't the planets collapse with each other??

So... Can I (amateur astronomer) detect extrasolar planets? I've seen some videos on how they are detected (by measuring radial velocity (I love this word:biggrin:) of that planet). But they said nothing about the instruments used in detecting these things. Can they be bought/made? I'm guessing...

I have a question regarding binary or multiple star systems and their [hypothetical] orbiting planets. I am curious if it is common (or even possible) for one or more of the orbiting planets to constantly switch the star they are orbiting, as in a figure eight shape. Can the stars "trade the...

Can there be stars and planets made out of antimatter?

Solar Wind is composed of magnetically charged plasma ejected from the Sun at a high velocity. By the time it reaches Earth the parameters are: ______________Min_Avg___Max Flux (cm-2s-1)---1----3----100 Velocity (km/s)--200-400---900 Density (cm-3)--0.4--6.5---100 Helium %--------...