Celestial body that orbits following an elliptical path around a star or stellar remnant.
3
votes
0answers
12 views
How did the radiative flux of each gas giant planet change with respect to time (since their formation)?
We know that each gas giant planet was warmest when it was young. This warmth came from internal heating from both radioactive decay and from gravitational potential energy. This warmth, in turn, ...
2
votes
3answers
12 views
Does anybody actually do astrometry in the 21st century?
I mean the nitty-gritty measurements of positions of stars and planets using transit circles. The transit instruments I've seen are mostly in national observatories and are essentially museum pieces: ...
2
votes
1answer
1k views
How long does it take for radio or light waves to travel from Earth to Jupiter, Saturn, Uranus, Neptune and Pluto?
I know it roughly takes 20 minutes from Earth to Mars, and 8 minutes from the Sun to Earth, but don't know how long for the other planets on my list.
2
votes
2answers
184 views
2
votes
2answers
85 views
Does Planet revolution time is always greater the more it's getting away from the center?
The entire question is in the title .
It's the case for the solar system but is it always the case ? Can a planet do a revolution faster than another that is closer to the center ?
As far as I ...
2
votes
1answer
74 views
How should I be thinking about tides?
I am working on a project for physics that involves tides. This is my current mind set when thinking about tides:
The earth applies a gravitational force on some mass ...
2
votes
2answers
177 views
How to correct flares and sharply focus on my telescope when viewing planets.
A month or two ago I purchased a “Skywatcher Explorer 130P Newtonian Reflector” telescope - which so far is brilliant when looking at the Moon, esp. using a neutral density filter. However, when ...
2
votes
1answer
82 views
Motion of mercury [duplicate]
I studied that mercury motion around the sun slightly displace by a certain value in each year. But, this is not predicted by kepler until general theory of relativity. What does general theory does ...
2
votes
1answer
57 views
Are the inner planets on planar orbits because there was more dust in the inner solar system (early on in planetary accretion)?
Question inspired by a question thread here.
So when there's lots of dust in a galaxy, the galaxy tends to collapse into a spiral galaxy (to maintain angular momentum and to minimize gravitational ...
2
votes
1answer
262 views
Radial fall in a Newtonian gravitational field [duplicate]
Suppose an object of mass $m$ starts at rest at a radial distance $ r_0$ from a perfectly spherical mass $M$ (where $m << M$), $r_0 > R =$ radius of $M$.
Can we analytically determine when ...
2
votes
2answers
53 views
Would a magnetic rod through Mars shield it from solar wind?
Would a magnetic rod going all the way through Mars shield it from solar wind?
2
votes
1answer
186 views
Where to find the current positions and velocities of the planets?
I've written a program which simulates the motions of planets and other bodies. I'd like to run it on our own solar system, but to do so I need to know the current positions (preferably in ...
2
votes
1answer
115 views
Planetary Gravity and its effects
This is my first question on the Physics portion of Stack Exchange. I was hoping to get some light on the topic of gravity. I don't have much background knowledge of physics so I might as well start ...
2
votes
2answers
86 views
Can one predict mass distribution in a solar system given the mass of the star?
I'm trying to write a program to procedurally generate solar systems at a reasonably high level (I'm not interested in doing an n-body dust particle formation simulation).
Is there some sort of ...
2
votes
3answers
707 views
Is it possible for the planets to align?
We've all heard the statement that on the 21st of December, the planets in the solar system will "align" from the point of view of the Earth. I assume this means that they would all be in the same ...
2
votes
3answers
341 views
Would a Helium powered balloon vehicle work on Mars?
Would a Helium powered balloon vehicle work on Mars? Things that might need to be answered:
How much liquidHelium would you need to pack in order to fill a balloon with enough helium gas to travel ...
2
votes
2answers
48 views
Interstellar bodies
As a solar system evolves the planets interact, and in trying to achieve a harmonious state some bodies are ejected. Space is big, but I have heard that some meteorites have been found with anomalous ...
2
votes
1answer
85 views
Synchronising the Earth's rotation via mass redistribution
How much material would have to be moved per year from mountain-tops to valleys in order to keep the Earth's rotation synchronised with UTC, thus removing the need for leap seconds to be periodically ...
2
votes
1answer
72 views
Magnetic field line length
If I had a magnetic bar in space that was 2cm wide and 2cm high and was one Earth diameter long and had the same magnetic strength as the Earth, would the distribution of field lines be the same ...
2
votes
1answer
125 views
How does one measure Earth's speed of revolution around the sun?
I know that there are several formulae that one can plug numbers into to arrive an estimate of Earth's speed around the sun (Kepler's third law for instance), but I'm wondering how these things are ...
2
votes
1answer
331 views
Metallic Hydrogen and Gaseous Planets
Jupiter has about twice the density of Saturn (1.33 versus 0.69 g/cm^3) because it apparently has a higher mass percentage of rocky core and of metallic hydrogen in its interior. Available density ...
2
votes
1answer
338 views
Why are the orbits of the planets in our solar system along the same basic plane? [duplicate]
Possible Duplicate:
Why are our planets in the solar system all on the same disc/plane/layer?
After watching this video I realized that the orbits of the planets in our solar system ...
2
votes
1answer
51 views
Single plane Ring system [duplicate]
Possible Duplicate:
Why are our planets in the solar system all on the same disc/plane/layer?
I've noticed this in many pictures, Planets are shown with a single ring around them (in some ...
2
votes
2answers
796 views
How gravitation effect on tides
I know that tide is caused by the gravitational pull of moon but what I don't know is how it effects on water. I have actually these doubts.
Why does gravity of the moon creates tides only in water?
...
2
votes
2answers
119 views
How does gravity behave outside the geoid?
I was watching a program about the geoid recently and the relative "height" of the Himalayan plateau gave me an idea. It makes sense for the geoid to be "highest" (is that the correct term?) there as ...
1
vote
3answers
164 views
The theory of moon creation when a Mars size planet hit Earth
As we know the predominant theory where does the moon come from is that a Mars size planet hit the earth and took a chunk out of it which eventually materialized into moon.
My question is that if a ...
1
vote
2answers
187 views
How can I visualize a gas giant?
From wikipedia
Gas giants are commonly said to lack solid surfaces, but it is closer
to the truth to say that they lack surfaces altogether since the gases
that make them up simply become ...
1
vote
1answer
185 views
Artificial planetary magnetic field
I wonder how difficult it is to create an artificial planetary magnetic field with generators? What power they would need?
The question is inspired by thinking about possible colonization of ...
1
vote
2answers
54 views
Will a spinning object come to rest?
Will a sphere spinning on its own axis come to rest given enough time, provided no other forces act upon it?
I know that if you have two spinning spheres in the depths of space and orbiting each ...
1
vote
2answers
105 views
Elements of a Planet reveals nearby supernova remnant?
During a random reading through this site, I found this one: Origin of elements heavier than Iron (Fe)...
The answer was "The formation of many elements in earth was due to Supernova nucleosynthesis" ...
1
vote
1answer
55 views
What causes the collapse of a Magnetic Field?
It's theorized that Mars once had a magnetic field which collapsed at some point.
There's also lots of speculation that a similar process will eventually happen to Earth. More recently has been the ...
1
vote
1answer
71 views
What's the amount of deviation of cellestial orbits from perfect ellipses
It's well known that the planets don't orbit the sun in perfect circles and the characteristics of the elliptical orbits which serve as better approximations to their motion have been calculated ...
1
vote
1answer
724 views
What is the relationship between mass, speed and distance of a planet orbiting the sun?
After reading this fascinating story about a new exoplanet, I was wondering about how mass, speed and distance determine a circular orbit of a planet around a star.
Given the mass of the sun and ...
1
vote
1answer
126 views
What equations/constants were used to calculate the Kármán Line for Earth?
I am interested in how the original value of ~100 km was calculated for the Kármán line of earth. What equations and constants would need to be used to reproduce this value?
Note: By constants, ...
1
vote
2answers
438 views
Altering Venus rotational speed to match Earth's via weather manipulation
Venus rotates approximately 6.5 km an hour Earth rotates approximately 1650 km/h how fast could we speed up Venus's rotation via only weather manipulation ( maybe a giant fractal lens between Venus ...
1
vote
2answers
182 views
Solar System Capture of Orphan Planets
NASA recently announced (http://www.nasa.gov/topics/universe/features/planet20110518.html) that orphan planets, planets no longer orbiting a star, may be more numerous than the stars in our galaxy. ...
1
vote
1answer
58 views
Has martian sunset same spectra than this earthly bluish-violet sunset?
Has martian sunset same spectra than this earthly bluish-violet sunset?
What about sunset on Mercury?
1
vote
2answers
38 views
Solar Catastrophe [duplicate]
Consider all of sudden the sun vanishes. What would happen to planetary motion. Will it continue to move in elliptical path or move in a tangential to the orbit immediately after sun vanishes or move ...
1
vote
0answers
61 views
What is the critical mass of a planet to have an atmosphere like Earth's?
Small planets/orbits like Moon cannot have atmosphere because of their masses. They don't have enough gravity to hold an atmosphere. Then what is the critical mass that makes enough gravity to keep an ...
1
vote
0answers
265 views
How do I find equations for the distance of the planets relative to one another?
I know I should be able to piece together some basic Newtonian equations for this, but I'm not sure where to start. I want to be able to choose one planet as the center and calculate its distance ...
0
votes
3answers
29 views
Why can't Jupiter be seen over Thanksgiving break?
As of these past few days, Jupiter can be seen in the sky, correct? Around Thanksgiving, why can't it be seen?
0
votes
2answers
48 views
Study of exoplanets reaching saturation point [closed]
In recent exoplanet meeting The Next 40 Years of Exoplanets, it was mentioned a few times that the field/topic is becoming saturated.
In what ways is it becoming saturated, and can you see the effect ...
0
votes
4answers
248 views
Age of universe estimates
I was recently involved in a discussion on a sister site regarding how tightly coupled Physics is with the age of the Universe (and Earth).
I believe that the Earth and the Universe are both billions ...
0
votes
1answer
175 views
Does the Earth's revolution around the Sun affect radioactive decay?
Premises:
The radioactivity is either hastened or slowed inside a fast moving aircraft.
Speed of fastest aircraft: 3,529.6 km/h.
The earth's revolution is: 107278.87 km/h.
The earth's ...
0
votes
2answers
54 views
Saturn ring stabilization
The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System.
I'm wondering, what power is primarily responsible for that stability?
© Public Image by NASA ...
0
votes
1answer
44 views
Motion of binary planetary system perceptible?
If one were standing on a body that is part of a binary system such as Pluto/Charon, would the g-forces of the motion of the planet be perceptible by a human?
0
votes
1answer
307 views
Atmospheric Escape of Gas Molecules
Most of the Bodies and Objects in space are likely to have an atmosphere. Since the space is empty, the gases in atmosphere should have either dissolved or emptied into space. But, Why doesn't this ...
0
votes
2answers
100 views
Atmosphere above huge fire areas (e.g., “fire ocean”)? [closed]
My question is more about climate sciences, but I hope that it is still related to physics.
What would be possible atmospheric conditions for planet with some kind of "fire" ocean?
I had some ...
0
votes
1answer
134 views
Is water necessary for forming the sedimentary rocks found on Mars' surface?
So, I've just been reading a recent ScienceDaily article, and came across this interesting quote
"Clays form in more neutral, less acidic conditions than the
sulfate-rich sandstones we've been ...
0
votes
1answer
122 views
Where do planets get energy to revolve around sun?
We know that every planet in our solar system revolve's around the sun in a particular orbit. But were to they get the energy to revolve around the sun. And why do they not drop into the sun there is ...
