1. ### B How scientists calculated the weight of Mars

How scientists calculated the weight of Mars to be 6.39 × 10^23 kg?
2. ### What is the period of the second planet in this exercise?

Homework Statement In a distant galaxy, a planet orbits its sun at a distance of m with a period of 108 s. A second planet orbits the same sun at a distance of m. What is the period of the second planet? Select one: a. s b. s c. s d. s e. Homework Equations T^2=constant * r^3 The...
3. ### 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...
4. ### SHM - Planet Problem

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...
5. ### I 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. ### I 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...
7. ### 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 earths life, to our knowledge life had only...
8. ### 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 *...
9. ### 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...
10. ### 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...
11. ### 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...
12. ### 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!
13. ### 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?
14. ### I Great oppositions of Mars

Why do the Great oppositions of Mars always happen at the same time of the year? What is that time?
15. ### Time dilation/difference between 2 planets

Hi folks, I'm writing a story which involves civilisations across multiple planets, and I've been trying to work out the impact of time dilation between them. I'm hoping someone can help me out here (thanks in advance!). (I'm not sure if this exact question may be applicable to one of the...
16. ### Object in orbit vs. object falling through a planet

If you havent seen this video before then go watch it :D Question: Answer: It is pretty hard to imagine it as a spring and here is why: 1) At (o) the spring should move by its inertia not by any force. If we look at the planet we can summarize that there are 2 points (As I think) that could...
17. ### Centripetal forces in our solar system

i calculated the centripetal forces in our solar system but i can't seem to find a connection using the centripetal force formula: Fmpz=(m⋅v2)/r i found out that the mean centripetal force for the planets around the sun is about 10^39, the mean centripetal of the moons around jupiter is about...
18. W

### Should we Colonize the Moon or Mars first?

I have reasons that have convinced me that Mars would be better, but I want to know what everybody else thinks.
19. ### Planet density -- no idea what to do

Homework Statement [/B] Consider a spherical planet of uniform density ρ. The distance from the planet's center to its surface (i.e., the planet's radius) is Rp. An object is located a distance Rfrom the center of the planet, where R<Rp. (The object is located inside of the planet.) Find a...
20. ### Stargazing Viewing stars through a refracting telescope?

Hello! I am learning about refracting telescopes and am slightly confused. I have read that a refracting telescope will magnify planets, but not change their brightness, but will not magnify stars as these will remain as point objects. It just makes the stars appear brighter. I am slightly...
21. ### Revolution of planets

How do planets continuously rotate on their axis or revolve around stars ? Do the energy they consume for this continued motion gets expelled as heat ?
22. ### Trajectory of planet

Hi all. This may be a stupid question to some.. But please do answer it. Why do planets move in an elliptical path? Why only ellipse? Or even a circular path for approximation? Why not a path which has corners? Like an octagon or a square?
23. ### Escape Velocity and Gravitational Force

Hey Guys! I've been doing a few equations in regards to planetary escape velocity and gravitational force. The below links have the escape velocity of listed planet on the left side of the board, the gravitational force between the Sun and given planet on the right side. In the middle of the...