Celestial body that orbits following an elliptical path around a star or stellar remnant.
3
votes
1answer
129 views
Earth-Moon orbiting each other after being engulfed by Red Giant
Recently some exoplanets were discovered which are thought to be the leftover cores of giant planets that had survived a star becoming a Red Giant and then shrinking back to a subdwarf.
If giant ...
4
votes
2answers
157 views
How could Horrocks have measured the AU?
I have always understood that the great historical significance of the transits of Venus, and the reason for the expeditions mounted to observe it, were that, by observing it simultaneously from two ...
1
vote
2answers
104 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" ...
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 ...
4
votes
1answer
92 views
Direction of planetary tilt
I am building a 3d solar system simulation using WebGL and have come across the problem of establishing the direction of tilt of the various planets. No I know the tilt of the planets in degrees what ...
4
votes
3answers
150 views
Why are planetary systems so rare?
According to this site there are 258 know planetary systems and 302 planets. Mostly each of the listed system has only 1 planet of Mercury's or Mars' size, while our system has up to 8 planets. From ...
1
vote
3answers
159 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 ...
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 ...
10
votes
1answer
130 views
The transit of Venus and solar neutrino rates
The following question was posed at the end of Maury Goodman's June 2012 long-baseline neutrino newsletter.
During the Venus transit of the sun, were more solar neutrinos
absorbed in Venus, or ...
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
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 ...
0
votes
1answer
60 views
What kind of light is needed to light up Venus?
Let's say I would want to light up Venus, such that we can see Venus all day long and not have to wait for a Venus Transit. What kind of light would I need for it? How powerful would it need to be?
7
votes
4answers
432 views
Are “broken” planets possible in the real world?
In the Star Wars universe, there are mentioned (or rather shown) two planets that had some kind of great explosion in their history. First is Peragus, with its exposed core, that partially exploded ...
2
votes
3answers
339 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
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
791 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?
...
0
votes
4answers
247 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 ...
3
votes
3answers
530 views
How do the Planets and Sun get their initial rotation?
How do the Planets and Sun get their initial rotation?
Why do Venus and Mercury rotate so slowly compared to other planets and why does Venus rotate in a different direction to Mercury, Earth and ...
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 ...
4
votes
2answers
554 views
Lowest gravity on Earth's surface?
I am trying to determine which on Earth's surface has the lowest gravity. Googling is not finding anything concrete. My natural inclination would be to think of Mount Chimborazo in Ecuador, being on ...
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
votes
1answer
72 views
How can you calculate the exact position of the Earth taking into account the gravitational attraction of Mars and the Sun?
I think there must be a formula to calculate the exact position of the Earth taking into account the gravitational attraction of Mars and the Sun. Is it possible with vectors?
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 ...
8
votes
1answer
14 views
Ring height stats?
I'm working on a basic simulation system which will include planets with rings, I want to create dust and asteroids within a 3D ring but I'm struggling to find any stats on the sort of height ranges a ...
7
votes
1answer
312 views
Falling into Saturn or Jupiter, would we pass through it until we hit the nucleus?
If we fall into Saturn or Jupiter, would we pass through it until we hit the nucleus?
Or would we hit the surface and stop there?
10
votes
3answers
443 views
Can you damage your eyes viewing Venus?
Whilst I know it is extremely dangerous to view the sun using a telescope (or even just looking directly at it for prolong periods) can you do permanent damage to your eyes looking at Venus through a ...
10
votes
2answers
379 views
Is it possible to see satellites with the naked eye?
Every now and then I notice some very bright "stars" in the sky. They tend to be very few (one or two, usually), and are quite much brighter than any other star out there. Often they're perfectly ...
4
votes
1answer
187 views
Does the Moon's orbital inclination follow the wobble in the Earth's rotation?
As the Earth wobbles during rotation, does the higher gravity at the equator tend to pull the moon toward an equatorial orbit even as the earth does that thousands of years wobble cycle? It would ...
4
votes
1answer
480 views
What would happen to Earth if Saturn were to exit the Solar System?
Suppose Saturn simply vanished. How would that affect the rest of the Solar System, specifically Earth?
5
votes
5answers
309 views
Computing Planetary Positions
Shortly, I will be beginning my third year at University in Computer Science, I am a software developer and I will be required to work on a final year project.
My idea for my final year project is ...
6
votes
1answer
134 views
Frequency of nomad planets passing within 30 AU of the sun
A recent estimate by the Kavli Institute for
Particle Astrophysics and Cosmology (a joint
institute of Stanford and SLAC) is that there
are circa 100000 times as many 'nomad planets' as stars
I ...
3
votes
1answer
135 views
Keeping air in a well
Let's say I've got an Earth-like planet with no atmosphere: it's just a barren ball of rock. I want to live there, but I don't like domes, so instead I'm just going to dig a big hole and let gravity ...
8
votes
1answer
75 views
Biggest crater in the Solar System
It seems that the biggest crater in the Solar System is Borealis Basin on Mars. The Wikipedia entry and this piece of news say it has been formed by an impact with a body of around 1600 - ...
1
vote
2answers
437 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 ...
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 ...
8
votes
1answer
90 views
Are Uranus and Neptune too big for their location?
So I was watching some TV, and I heard Dr. Plait mention that the planets Uranus and Neptune are too big to be located so far out in our solar system. Now, I heard his explanation on the show as to ...
-1
votes
3answers
139 views
Earth's stationary iron core
Why is the earth's iron core stationary, while the liquid matal circles around it creating the magnetic shield. Don't understand how can the entire planet rotate where as the planet's center is ...
14
votes
1answer
232 views
Why don't any of the gas giants have moons of Earth's mass (or greater) that orbit them? Is this generalizable to exoplanet gas giants?
Now, we know that the composition of the outer planets tend to contain a much higher ratio of ice over rock. [1] So the lack of Earth-like moons around the outer planets that this could be an artifact ...
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
260 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 ...
3
votes
1answer
58 views
Cassini: What information could be gained from the 2017 impact with Saturn?
First of all:
Will Cassini be operational in 2017 (pending no unforeseen equipment failures)?
Power
Communications
...
What information could we gain?
Properties of Saturn
How to build more ...
8
votes
1answer
505 views
How big (compared to our moon) would Saturn look from Titan's surface?
How large in the night sky would Saturn look from Titan's surface? I believe they are tidally locked.
18
votes
3answers
592 views
Why do the planets' orbital distances fall on an exponential curve?
Background: I was recently reading a book on the planets to my son and I noticed a pattern in the distributions of the planets. The planets' distances roughly follow an exponential distribution.
...
5
votes
1answer
6k views
Is the moon a planet?
Can our moon qualify as a planet? With regard or without regard to the exact definition of the planet, can the moon be considered as planet as Mercury, Venus and Earth etc. not as the satellite of the ...
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.
6
votes
1answer
289 views
How many Pluto sized planetoids have been discovered?
How many planetoids have been discovered that are, say, 50% the size of Pluto or larger? Where are they?
Incidentally, what is the difference between a planet, a planetoid, and an asteroid?
4
votes
2answers
28 views
Lumped circuit model of Earth and Sun as a thermal system
I want to design a thermal model of the Sun heating up the Earth. The circuit below is my own design (I don't know if there is a better way to model it. If there is, please tell me.). I want to ...
7
votes
1answer
49 views
How plausible is a subsurface ocean on Pluto?
According to this article on physorg.com, it's likely that Pluto has a subsurface ocean of liquid water. It suggests that the ocean would be about 165 km deep, under an equally deep crust of solid ...
5
votes
6answers
547 views
Why does the earth rotate? [duplicate]
Possible Duplicate:
Why does every thing spin?
So why would the earth, or any planet for that matter, rotate along an axis? I know of no force which could come into play here, so i assume ...
6
votes
1answer
21 views
Liquid Water in “mid-ice” on Europa. Mechanism?
Recently I read this entry by Dr. Phil Plait (a.k.a. The Bad Astronomer). He is talking about a lake of water contained within the ice layer of Europa.
the lake is completely embedded in the ice ...
