Astrophysics
posted by Judy .
I'm having trouble understanding the formulas for determining a planet's distance and mass.
A planet's distance is related to the period of revolution and the mass of the central star (e.g, the sun). The relationship is called Kepler's Third law. Distance can also be determined applying trigonometry, using parallax measurement.
The mass of a planet can be determined easily if it has satellites, by again using Kepler's third law. A planet's mass can sometimes be obtained by measuring its "perturbation" effect upon the orbit of a nearby planet or a space probe flying by.
Let us know which formula you are having trouble understanding and one of us w3ill try to provide more specific help.
Respond to this Question
Similar Questions

Physics
The star has a mass n_1 times that of the planet, which orbits this star. For a person on the planet, the average distance to the center of the star is n_2 times the distance to the center of the planet. In magnitude, what is the ratio … 
Math
The period of revolution of a planet around the sun is the time it takes for the planet to complete one orbit of the sun. The period, P years, is give by Kepler's third law P^2=D^3, where D is the average distance from the sun in astronomical … 
Astrophysics
You know M(r) = v^2r /G d = distance; s= speed Planet 1: d=2/s=120 Planet 2: d=4/s=60 Planet 3: d=9/s=40 Planet 4: d=16/s=30 Planet 5: d=36/s = 20 You use the distance and orbital speed of the first planet to determine the mass enclosed … 
Physics
mass of star = 3.80 x 1030 kilograms mass of planet = 6.35 x 1024 kilograms mass of moon = 7.63 x 1022 kilograms average distance from star to planet = 1.56 x 1011 meters average distance from planet to moon = 4.26 x 108 meters Use … 
Astronomy
Orbital speed is the speed with which a planet moves around the sun. The speed is determined by: a)the mass of the planet only b) the mass of the sun only c)both the mass of the planet and the mass of the sun d)the mass of the planet … 
science
if all of the following imaginary planets were the same distance from the sun, which would experience the strongest force of gravity due to the sun? 
Physics please help ASAP!
If you know the mass of a star and a planet’s radius and speed at perihelion (closest approach to the star), then using conservation of energy and angular momentum you can solve for the radius and speed of that planet at aphelion … 
Astro
A newly discovered planet orbits a distant star with the same mass as the Sun at an average distance of 118 million kilometers. Its orbital eccentricity is 0.5. A.Find the planet's orbital period. B.Find the planet's nearest orbital … 
Ap physics 1
The mass of a star in a galaxy far, far away, is 3.12 × 105 Earth masses, and the mean distance from the center of this star to the center of a planet with the same mass as our Earth is 2.46 × 108 km. Treating this planet and star … 
Physics
The mass of a star in a galaxy far, far away, is 2.13 × 105 Earth masses, and the mean distance from the center of this star to the center of a planet with the same mass as our Earth is 7.87 × 108 km. Treating this planet and star …