Planet Definition and 820 Threads

Homework Statement Homework EquationsThe Attempt at a Solution Honestly , I have not been able to understand the question . I am totally clueless about the part written in parenthesis . All I understand is that since the length of the rod is not negligible ,value of gravity at the location...

Has the spectrum of light that is reflected off planet Earth ever been measured from outer space? (In the same sense that we measure spectra of the light emitted/reflected from other celestial bodies in astronomy). If so, would it be possible that there could be dips in the spectrum resulting...

Homework Statement Homework Equations [/B] The two equations in the image, as well as (maybe) standard vector operations like dot product, cross product. The Attempt at a Solution [/B] So, I've tried to do what my instructor suggested and put everything in terms of Earth (Using RE and TE...

Homework Statement Homework EquationsThe Attempt at a Solution If P is the power radiated by sun and R is the radius of the planet then power per unit area at a distance d will be P/4πd2 . I am not sure about how to calculate the power received by the planet .Do I need to multiply the above...

Announcement Vanderburg works on various stuff, with a focus on more recent data (K2 mission). Jessie Dotson works on K2 data and seems to be a contact person for external users working with Kepler data. Christopher Shallue https://www.linkedin.com/in/cshallue/. Based on the panel, I have no...

Suppose life would evolve on a planet near a black hole, like the water planet on Interstellar. And just like on Earth, they eventually discover a theory of relativity and also how to send a rocket away from planet/black hole and back. Could they take advantage of the huge time dilation between...

I was wondering if it is possible to use only a stopwatch and a telescope to find the mass of a planet, such as Saturn. I've experimented with a couple of things but I keep running into problems. I previously asked this question in the homework section, but it does not involve numbers, is not...

Hello, I've been searching for a collision simulator for planets that uses SPH. I haven't found any though. US2 doesn't use SPH collisions. But does anyone know any that are publically available? Example video below: And a channel with a few: https://www.youtube.com/user/joetaicoon/videos

Homework Statement "In January 2006, astronomers reported the discovery of a planet comparable in size to the Earth orbiting another star and having a mass of about 5.5 times the Earth's mass (5.97 x 10^24 kg). It is believed to consist of a mixture of rock and ice, similar to Neptune. If this...

You've finished with your garden planet and vacation planet, now you want to do something creative.

Homework Statement "In a galaxy far far away, a planet composed of an incompressible liquid of uniform mass density ρ has mass mplanet and radius R. Determine the pressure midway between the surface and the center of the planet." I used M=mass of planet, m=mass of shell, R=radius of planet...

I had this discussion while driving home to California from a trip to Washington state with a friend. We were discussing the stability of a completely rigid, untethered, ring-structure around Earth, and I did not know how to explain to him that such a thing must be tethered by rigid towers lest...

My question is, take Mars, say, and install a huge rocket engine on the ground pointing out the planet (obviously) and in the opposite direction of its velocity, so that if it is turned on, the planet is slowed. The rocket starts to work and Mars is slowed. If the loss of velocity goes little by...

A certain planet has a vector (Recl, L, B). The Earth and Sun vector exists on ecliptic. I need to know how to calculate the compound angle between the planet vector and the Earth-Sun vector.

Has anyone watched the latest War of the Planet of the Ape? I forgot about the virus the wiped out humanity so I rewatched the earlier installments. And learned they needed to introduce stronger virus strain to serve as carrier for the formula to reach the brain because the earlier one showed...

Hi, Consider a spherical planet of mass m and radius rp orbiting a star with a circular orbit of radius ro (distance from axis of orbit to the planet's center of mass). The planet has an angular velocity ω. Say we wanted to find the magnitude of the angular momentum of the planet. Going about...

I rewatched the Matrix I, II, and III. The AI machines have evolved so much they have their own cities. Which made me wonder.. If a planet were totally inhabited by AI machines. Would they still be individual android with its own personality.. or a collective personality? What sci-fi movies...

The hottest planet yet is twice Jupiter’s size and hot as a star by Leah Crane Link: New Scientist This planet is 7800 degrees F--versus "only" 860 degrees F for the Sun's hottest planet, Venus.

Homework Statement A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.70 × 104 m/s, and the radius of the orbit is 5.25 × 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has a radius of...

Hi fellas. First of all, sorry for the bad english, as it's not my main language :) Short story to explain my needs. A few years ago, a night tale to my daughter was about a little girl who lived in a peculiar planet. It was pretty hot on one side and then hottest on the pole, there was a not...

This thread will contain several follow up questions, but let me start with the most simple one. Imagine a planet with no atmosphere and a ball in empty space. The ball is dropped on the planet from a certain height and starts bouncing. We ignore friction and consider this to be the fully...

Homework Statement There is a planet (spherical) with a hollow that is concentric with the planet.if the inner radius is r and outer radius is R and mass of the planet is M what would the gravity be outside of the planet at distance x from the center ? Homework Equations Shell theorem...

I know, this question probably have asked many times, but I unable to post in that closed threads, so... We have a Planet, (let's say of size of the Earth, and that have a population of the Intelligent Creature - IC, on level of evolution and progress something near a mankind current level, so...

Non-Scientist here. Assume that you had a two body system (planet-moon, double-planet) where one of the bodies was very close to tidally locked. Say they are closely co-orbiting at 6 to ten diameters in a relatively quick 20 to 50 hour orbit. One of the planets is close to being tidally...

Homework Statement Suppose there is an object that is a distance ##r_0## from the center of a planet that is nearby (the object is outside the surface of the planet). Let ## r ## represent the distance from the object to the planet's center. Let ## t ## represent time. The object, which is...

Hypothetical question that came up in World Building stack exchange. The question asked for what the longest reasonable day length would be. I thought that a 100 hour day: * Afternoons in what are now hot deserts would be uninhabitable. * Frost traps in more polar climates would be...

For example let's a satellite was orbiting the moon which has no atmosphere. If the moon suddenly started spinning twice as fast would it effect the satellite's orbit even though the satellite is separated by the vacuum of space from the moon? Easier way to put it, if the Earth suddenly spun...

I thought that I'd posted this here, but perhaps not. I've had it on the OtherWorlds and the Physics stackexchange with no results. I grew up with countless alien planet covers depicting 2-3 moons all considerably larger (telephoto lens...) than Luna's appearance from earth. Luna from Earth...

The following picture shows a rogue planet (in purple) approaching Earth (in blue). It is spinning prograde like Earth. We're talking about a close approach. For example a planet the size of the moon approaching within 12,000km of Earth. That would be just outside the roche limit. I presume the...

Question: Finding the closed formula s(t) that gives the approaching position of an inertial mass to a planet Supposing the mass initially stationary, and far enough and for long enough that it is NOT possible to consider the gravity as constant while it moves closer and closer. Said in a...

Homework Statement An experiment is conducted on a "strange" planet to determine the acceleration due to the force of gravity there. A 2 meter length pendulum is suspended and put into horizontal circular path. Data collected: the pendulum makes 10 revolutions in 25 seconds while sweeping out a...

Confession: I have no background in astronomy. I'm not even sure whether this question is apt. So a hypothetical situation goes like this. One of my friends is filthy rich and has one of those richman fantasies. By chance, a space science institution is willing to offer him a trip to planet X...

So I'm reading in the news and a group of scientists from the New Horizons missions appear to be reopening "The Pluto Debate" with yet another new definition of planet at the Lunar and Planetary Science Conference in March:rolleyes:. If accepted their definition of planet would increase the...

Homework Statement I am doing a MATLAB simulation for a spacecraft that splits into two near a planet, and one part enters the planet's orbit while the other part avoids the orbit. I am a bit unsure about the physics of the split. Since there is a net force due to gravity, I guess momentum is...

Suppose we are watching a star that is spehrical. But we will see its one face that is toward us(suppose its not rotating). We will see that face to be plane circular. Is there any way we can find the curvature? or tell if its spherical or disk shaped ?

Homework Statement You land on an unknown planet. The first night you note that its celestial pole is 40 degrees above the northern horizon at your current position. Your flight module is able to go 1000 km/hour. You fly an hour due south, and note that the celestial pole is now 30 degrees...

Imagine someone in a planet at the farthest star of the farthest galaxy from ours. From that planet would the sky be a half black and the other half full of galaxies? Could a star be at the "edge" of the universe or general relativity contradicts that?

There are approximately 15 000 nuclear weapons on the planet. The largest one as far as I am aware is the Tsar Bomba, which packs a punch of (rounding here) 100 megatons of TNT. So if all of them were Tsar Bombas, we'd be looking at 15 000*100 megatons TNT = 1 500 000 000 000 tons TNT. Source...

I want to describe a planet that has 13 fifty-two day months and a 36 hour day. IF someone could point me to a place where I can figure this, it would be appreciated. What's the math?

Hey, was trying to think of what the safest possible place in existence would be and got to thinking of a planet surrounded by 6 black holes of equal size. Say the black holes met around this planet at the precious same time and are held in equilibrium, is there any particular reason that a...

Homework Statement The periodical oscillations of the spectral lines of a star incicate that there is a planet orbiting around it with a period of 2.1375 days.Calculate what the observed wavelengths of the NaI double line will be,which is normally observed at 586.6nm and 589.6nm. Star's...

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when any exoplanet passes through any star we can see the intensity dip from which we can detect the planet when an exoplanet passes through any star by spectroscopy we can find planet composition. So my question is did star glare effect light which is passes through planey atmosphere?

When a planet passes through any star, it absorb and transmit certain amount of light by which we can determine planet composition. My question is that did stars glare hide or inturupt the wavelength transmitted of reflected by planet?

Homework Statement A satellite is in circular orbit at an altitude of 800 km above the surface of a nonrotating planet with an orbital speed of 3.7 km/s. The minimum speed needed to escape from the surface of the planet is 9.8 km/s, and G = 6.67 × 10-11 N · m2/kg2. The orbital period of the...

Here's what my prof says: "Define F_{mean} to be the mean force, F_close to be the force on the side of the Earth closer to the moon, and F_far to be the force on the side of the Earth furthest away from the moon. On the closer side the net force is F_close - F_mean > 0 On the further side the...

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...

I thought of this 'paradox' which is somewhat similar to the twin paradox but can't be explained by a lack of symmetry etc. It is very similar to many paradoxes I have heard before of which the resolution is known (which is why I am mostly sure this can be resolved) Bob is looking through his...

Homework Statement (a) Prove that the time average of the potential energy of a planet in an elliptical orbit about the sun is -k/a. (b) Calculate the time average of the kinetic energy of the planet. Homework Equations F = \frac {-dV} {dr} = - \frac {k} {r} The Attempt at a Solution [/B]...

I know that it is probably a gas giant, but why blue? Saturn and Jupiter, and even Uranus aren't blue, so why would Planet X be blue?