Planets Definition and 515 Threads

  1. diegzumillo

    Stargazing Possibility of small bodies of liquid etc

    I'm a physicist but my field is at the other side of the spectrum, but my curiosity has no bounds :P Based on observations we know of several configurations 'clumps of matter' can take, like planets, gas giants, comets, or basic rocks etc. But I always wondered about more unusual possibilities...
  2. wolram

    B Formation of Hyperion System: How Planets Form Far from Stars

    So how did the Hyperion system form with planets so far from there star. https://www.sciencedaily.com/releases/2018/10/181015104531.htm
  3. komarxian

    SHM: Planet Problem Homework Statement

    Homework Statement You are exploring a newly discovered planet. The radius of the planet is 7.20 * 107 m. You suspend a lead weight from the lower end of a light string that is 4.00 m long and has mass 0.0280 kg. You measure that it takes 0.0685 s for a transverse pulse to travel from the...
  4. U

    Thoughts on magnetic fields and life on planets.

    After reading about Jupiter's magnetic field on ScienceAlert, I remembered another article about tree bark and magnetic anomalies (links below). I also remembered an article on birds being able to see magnetic fields as well. It got me thinking of how and if life is possible on anything other...
  5. DLeuPel

    Regarding the radius in the orbital velocity

    Would the velocity of a body which is orbiting another body change due to its radius to the center of gravity? If so, why? A body which moves passed a planet and starts orbiting it should have the same velocity it had before ,regarding the fact that it is orbiting a planet. Also, gravity isn’t...
  6. E

    B Would planets fall out of orbit when gravity has a speed?

    As I understand it, Newton considered the influence of gravity between two objects to be instantaneous. Now it would appear that gravity has a speed limit. If the Earth is influenced by the sun from where it was 8 minutes ago, how does the Earth keep up with a traveling sun? Does relativity...
  7. L

    Maple Computational Hohmann Transfer on MapleSoft

    Hi, I am trying to recreate an Interplanetary Hohmann transfer orbit from Earth to Mars similar to image A below (the red line). However, Earths orbit is not circular, It is more of an elliptical orbit rather than circular. I was able to successfully plot the orbits of both Earth and Mars...
  8. A Alex P

    I Are Stars and Planets Differentiated by Nuclear Processes in the Solar System?

    In solar system, we have sun and planets revolving around it. We have satellites orbiting around some of planets. Are all of these are same thing, just differentiated on the basis of size and nuclear processes occurring inside them? I mean, if nuclear processes occurring inside their core its a...
  9. Toreno

    Calculating orbits of planets in Solar System

    Hi, I am about to write a simple application, simulating in 3D current location of the planets in Solar system. Honestly, I do not know even how to start. Can you please guide me where could I find some good information on planet orbits, current locations and how to make all of the calculations...
  10. K

    I Can Newton's Theory of Gravity Explain Planetary Elliptical Orbits?

    Is it difficult to use Newton's theory of gravity for showing that planet's orbits must be elliptical?
  11. C

    I Can a Single Observation Determine Retrograde Motion?

    Hi I was wondering: if we know the geocentric coordinates of the sun and one planet (longitude and distance) in one instant only, can we calculate/know mathematically if the planet is in retrograde motion or not? Or must we have 2 observations? Clear skies CPtolemy
  12. jim mcnamara

    I Extragalactic Planets Observed Using Microlensing

    http://iopscience.iop.org/article/10.3847/2041-8213/aaa5fb/meta (abstract). Using microlensing the authors observed (my bolding): Does someone know the reason why unbound planets are the only reasonable way to explain their data? This is not my field, but looks like a big stretch to me, a...
  13. Ethan Singer

    Why aren't less massive objects also spherical like planets and moons?

    given that gravity pulls things together into spheres, how much mass is needed to do so? Smaller objects such as asteroids, meteors, and that bench in the park don't just turn into spheres, because they lack enough gravitational force to dominate the shape. So at approximately how massive do...
  14. G

    Two Planets Touching: Is it Possible?

    Hello, This may not be possible But, suppose there were two planets about the same size as Earth. Suppose both planets touched each other. Think of sticking two balls of ice cream together with an ice cream scoop. Imagine walking on the surface of one planet up to the point where the two...
  15. P

    I Magnetic field of Solar System planets

    Hello. I am reading a paper which says that only Earth (between the rocky planets) keep a strong magnetic field and it arose an question on this: Why does the magnetic field of the planets decrease with time in such planets? Why the magnetic field of the Earth is the only one which keeps strong?
  16. F

    Life on other planets, are we looking at the wrong planets?

    Scientists are looking for Earth like planets/bodies to find life on other planets/bodies, somewhere that is warm enough that liquid water can exist, and somewhere with basic organic molecules. Here's where I have a concern, in the 4 billion years of Earth's life, to our knowledge life had only...
  17. N

    I Why are the planets revolving around their own axis?

    As we know that most planets has two motions around the sun , one revolving and one rotation on its own axis. So what exactly is the reason for this motions to come into play.
  18. davidge

    B How many planets can we estimate in other galaxies?

    How far are we from being capable of estimating the number of planets in other galaxies? At least, in any of the nearby galaxies that are already known to us? Would this require state-of-art equipments?
  19. maltmana

    I Planetary Orbits: Force needed for circular orbit

    Hi! first time poster here. I'm making an orbital simulation and I am having a problem with one minor detail. The gravity is working great, and I've programmed it using this formula: A force vector is applied = DirectionOfCentralBodyNormalized * ((GravConstant * centralbodymass *...
  20. lpetrich

    B How Does Earth's Water Compare to Potential Ocean and Desert Planets?

    Let's first look at our homeworld, to use as a reference. The Earth's surface water has a mass about 0.00023 times the Earth's total mass, with the planetary ocean having 96.5% of it. The ocean has a mean depth of 3.8 km, and they cover 71% of the Earth's surface, giving a planetwide average of...
  21. G

    I Mercury's precession due to other planets

    Hi. I'm interested in how physicists in the mid-19th century such as Urbain Le Verrier were able to compute the gravitational influences of the other planets on the apsidal precession of Mercury's orbit, finding that they can only explain about 531" (per century!), not the observed 574". This...
  22. T

    I Math doesn't add up: stars + planets < particles in universe?

    I see they finally counted all the particles in the universe, it's10 to power of 80 They also counted all the planets: 10 to power of 24 and also counted all the stars: 10 to power of 24 and also counted all the atoms in the Earth: 1.3 x 10 power of 50 Good work everyone! Now, I'm trying my...
  23. Edward Barrow

    I Is a superflare capable of changing a planets orbit?

    I'm examining if a massive superflare early in the solar systems history could be the explanation for the odd positions of certain planets and moons in our solar system (and their rotations). For this test, I've taken Mars as an example. I’m going to place Mars in the early solar system in an...
  24. K

    Three Planets I See Large and Small....

    I have by no means any education on the question I am about to ask. I have looked on the internet and find myself here, signing up for an account to see if anyone can point me to any research on the subject. I thank you in advance for any help that is in layman terms. Scenario: 3 planets...
  25. M

    B Kepler's 3rd Law, geometric relationship?

    Hello, quick question here I am studying mathematical astronomy / the history of , and I have noted that by raising the average sidereal period of any planet in our solar system, to the power .666666, that you are left with the average distance of that planet from the Sun, in AU I was told...
  26. virgil1612

    I Do Red Dwarfs Favor Rocky Planets and Host Life?

    Hello, 1. Does the star type influence the type of planets forming around it? Specifically, could a red dwarf favour the formation of rocky planets around them, compared to gas giants? 2. Planets would be much closer to a red dwarf star than they are for a solar type star. Consequently, the...
  27. D

    B Generating Plausible Star Systems

    I'm trying to write some code to generate plausible star systems, but so far, I only have a main sequence star generator, and even with that I don't know how good the mass-radius relationships are. So, I'm coming here to ask for some formulas or pointers as to where I can go to find the math to...
  28. L

    B Can Planets Thrive in Binary Star Systems?

    How can planets exist in star systems with two or three stars? Shouldn't the planets' orbits get severely disturbed by the other stars?
  29. L

    B Top 3 brighest planets as seen from other planets

    I'd have to think Jupiter from Mars would be the brightest but after that it's hard to say. Any guesses?
  30. Edward Barrow

    I Why is there no "mid-Atlantic ridge" on other planets?

    Our planet has scars going all the way around it. The most famous of these is the mid-atlantic ridge. How come Earth is unique in this respect? There are none on Mars for example: How come we don't see any such feature on Mercury, Venus or Mars?
  31. S

    I Why do planets follow the same curvature at both foci?

    We are told that planets and comets orbit the sun in an ellipse (Kepler's 3 laws) as shown below: We are also told that according to Einstein's theory of gravity, there is no force applied. Implied is that the planets move in straight lines through curved space. We know that the effect of...
  32. A

    B Temperature in the space between planets of our solar system?

    I know that the overall temperature of the universe is microwaves at 3 Kelvin or so from the Big Bang, but is this mostly for deep space? Or is this pretty much the temperature in our solar system also, assuming a coordinates some distance away from any of our planets but still within our solar...
  33. G

    B Height measurement on other planets

    If you measure the height of a mountain, you compare it's height with the sea level. But on let's say mars, how do you measure height when there is no sea to compare with? For example: Olympus Mons is considered to be the tallest mountain or vulcano in the solar system, but what is the level on...
  34. E

    How to calculate the electrical field of planets?

    All, I am not sure if this is the right forum for this but I believe it is the closest to the question I would like an answer to. I would like to calculate the electrical force between Mars and the Earth. I believe I understand that in order to do this, I must apply Coulomb's law: E=...
  35. Andy Resnick

    Stargazing Can Pluto be seen with amateur telescopes?

    Clear skies are gone for the winter, here's as much as I was able to get. Next summer I may have a chance at Pluto. First one is Uranus, next one is Neptune- they look a little different because I scaled them differently to fit. Enjoy!
  36. petrushkagoogol

    I Are all planets in our Solar System in the same plane?

    Are all planets in our Solar System in the same plane ? :))
  37. G

    Stargazing What telescopes are good for seeing planets and galaxies?

    Hello, I am currently considering on buying a telescope to do some of my own research and for sight seeing. Any recommendations? I would prefer to have a telescope that requires me to use code or at least a computer so I can familiarize myself with the mechanics.
  38. S

    Calculate the Orbital Radius of a Planet

    Homework Statement Planet X of mass mx = 2.1 × 1024 kg orbits S in uniform circular motion at a distance rx and with a period Px = 2.1 years (=66225600 s). The mass of the star S is MS = 2 × 1031 kg and its radius is RS = 3.2 × 108m. Homework Equations T=2pi * sqrt(r3/(GM) The Attempt at a...
  39. S

    Calculating the Year Length of a Gak Planet

    Question: A Gak it a type of alien that lives on a planet in another galaxy. One day a Gak decides to find out a little more about his planet. He drops a ball (it starts at rest) with a mass of 6.18 kg and notes that it takes 0.928 s to fall a distance of 8.37 m. The Gak’s planet orbits its sun...
  40. A

    I Plotting the orbits of the planets

    Hello everybody! Long-time lurker and second-time posting. I'm working on a project for my math class, and I'm trying to plot the orbits of the planets using vectors. I've chosen to use MATLAB because I am decently familiar with it. I've used the formulas described in this post here to get my...
  41. benarceneaux

    How Can I Generate Realistic Planets for My Game?

    Hello everyone! I'm working on a game and I've been trying to wrap my head around procedural generation of planets. Sounds super difficult but I don't think it actually needs to be all that complicated. I don't need to generate a planet using physics, instead I'd like to generate the planet...
  42. A

    I What is the average number of planets per star?

    What is the occurrence rate of planets? I'm not talking about earth-like planets, but any planet in general. I can't find a source that examines this number, all I can find is the average number of earth-like planets. Can anyone lead me to a useful paper/source? Thanks in advance
  43. N

    I If radiowaves are reflected from objects (i.e planets)....

    ...and they can penetrate a bit in the surface, we could image the subsurface right? I do not see the problem... Help please!
  44. N

    B Can we know what exists in planets' subsurfaces?

    imagine this situation: there's a very similar planet to Earth with almost the same atmosphere and surface. we want to know what lies beyond the surface to know if life exists there. so could we send or observe radio waves or microwaves with a similar telescope as arecibo that penetrates several...
  45. S

    A Planar orbit of planets around sun

    Imagine thee planets interacting through gravity, mathematically how should they come and rotate in a same plane, like planets and sun?
  46. A

    I Why do Great Oppositions of Mars Always Happen at the Same Time of Year?

    Why do the Great oppositions of Mars always happen at the same time of the year? What is that time?
  47. wolram

    Is Intelligent Life and AI Common Across the Universe?

    Is life common in the universe ? or do we live in a special space and time. https://www.sciencedaily.com/releases/2016/07/160711155538.htm
  48. Astronuc

    B Outer Solar System Origins Survey, Dwarf Planets and TNOs

    "Nearly 1000 TNOs known to inhabit the outer Solar System have been discovered by OSSOS (or earlier CFEPS)." - OSSOS http://www.ossos-survey.org/tnodb.html "Started in February 2013, OSSOS is a four-year project using the MegaPrime camera, a 1x1 degree imager on the 3.6m Canada-France-Hawaii...
  49. petrushkagoogol

    A Must Planetary Systems Have Retrograde Orbit Planets?

    Is it mandatory for any planetary system like our Solar system to have a retrograde orbit planet in it's midst ? Is there any upper limit for the same ?:))
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