Celestial body that orbits following an elliptical path around a star or stellar remnant.

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4
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3answers
340 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 ...
5
votes
1answer
274 views

Convert latitude of lowest altitude to argument of perigee?

I am designing an orbit around Mercury. I know the values I want for the semi-major axis, eccentricity, inclination, and RAAN. I want the altitude of closest approach (periapse) to occur at ...
18
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2answers
874 views

How deep is the Great Red Spot?

The Great Red Spot (GRS) is a very persistent storm system that's easily visible through a telescope on the surface of Jupiter. But what is the three-dimensional structure of the GRS, and how deep ...
4
votes
4answers
10k 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 ...
53
votes
5answers
5k views

Is there a small enough planet or asteroid you can orbit by jumping?

I just had this idea of orbiting a planet just by jumping and then flying upon it on its orbit kind of like superman. So, Would it be theoretically possible or is there a chance of that small body to ...
3
votes
1answer
303 views

What is the critical mass of a planet to have an atmosphere like Earth's? [closed]

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 ...
2
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2answers
3k 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 ...
3
votes
1answer
160 views

What is the maximum mass of planet HD 40307 g

Recently discovered planet HD 40307g around HD40307 Star system is claiming that its inside a habitual zone of a solar system. Besides It has water where life could be evolved. I tried to calculate ...
4
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0answers
158 views

Hemispheric dichotomy of Mars and unstable spin axis

Is the following explanation plausible? Can you spot any flaws? Mars doesn't have a large moon to stabilise its axis of rotation. At some point early in its formation its axis might have been ...
4
votes
1answer
218 views

What day/night cycles, climate and seasons would experience Alpha Centauri Bb inhabitants?

Alpha Centauri Bb is an exoplanet orbiting Alpha Centauri B. It is asserted that given the close distance to the star the planet should be tidally locked. The orbiting period of the planet is about ...
2
votes
1answer
3k 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 ...
1
vote
1answer
3k 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 ...
5
votes
2answers
3k views

What does the phrase “limb of the earth” or “atmospheric limb” mean?

What does the term limb of the earth (see this question, for example) or atmospheric limb mean? The phrase strikes me as very odd, since earth is nearly spherical. Do other planets with atmospheres ...
5
votes
1answer
3k views

How do astronomers measure the distance of the planets from its star?

I know they have accurate means of measuring the distance of the planets in the Solar System from the Sun. I'm skeptical how can they use the same tools or techniques for other systems so far away as ...
2
votes
1answer
80 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 ...
0
votes
1answer
499 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 ...
5
votes
1answer
258 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
217 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
1answer
935 views

Atmospheric escape of gas molecules

Most of the objects in space are likely to have an atmosphere. Since space is void, the gases in atmosphere should have either dissolved or emptied into space. But, some of the objects still seem to ...
4
votes
1answer
132 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 ...
5
votes
3answers
194 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 ...
2
votes
3answers
551 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
131 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 ...
19
votes
1answer
290 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
310 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
155 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
66 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?
6
votes
4answers
2k 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 ...
6
votes
2answers
386 views

Does a tidally locked planet have seasons?

Could a tidally locked planet have seasons? According to my understanding, a tidally locked planet rotates around itself exactly once per rotation around its sun. However, if the axis of rotation of ...
2
votes
3answers
924 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
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1answer
147 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 ...
3
votes
2answers
2k views

How gravitation affects tides

I know that tide is caused by the gravitational pull of moon but what I don't know is how it affects water. I have actually these doubts. Why does gravity of the moon creates tides only in water? ...
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vote
5answers
323 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 ...
5
votes
3answers
3k 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 ...
3
votes
2answers
2k 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 ...
5
votes
3answers
7k 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 ...
2
votes
2answers
875 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
149 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?
3
votes
2answers
165 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 ...
9
votes
1answer
19 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 ...
13
votes
1answer
952 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?
11
votes
3answers
2k 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 ...
11
votes
3answers
2k 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
273 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 ...
5
votes
1answer
2k 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
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5answers
969 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
160 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
174 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
158 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 - ...
3
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1answer
823 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 ...