Hi.  These are a few questions I cannot find for my Astronomy class.  Can someone help???\n\nWhat is the term that refers to the process by which heavier elements sank to the center of the center of the Earth displacing lighter elements which in turn rose to the surface?\n\nWhat is the term that refers to the process by which gases escaped from the interior of the Earth and resulted in the formation of the atmosphere and the Oceans?\n\nWhich solstice or equinox marks the time when the Sun looks as it is crossing the plane of the equator on its way north.?\n\nWhat two forces combine to bring about a slow rotation of the Earth’s axis which in turn results in a sow westward rotation of the equinoxes?\n\nWhy is the intersection of the Earth’s equatorial plane and the ecliptic important in astronomy?\n\nThanks in advance!
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1. Diferentiation\n\n2. Outgassing\n\n3. Spring (vernal) equinox\n\n4. This is just presession, the natual motion of a spinning body in a graviational field. not sure what "forces" you are looking for.\n\n5. It marks the equinoxes, the days of the year of even amounts of sun and dark, and we start several of our coordinate systems from the point of the spring equinox.
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u might have heard abt latitudes. Sun light constantly falls on earth. as earth moves different past of earth receives light and this is what we term as day and night. Latitudes help in determining times and it takes 15mins for sun to pass from one latitide to another. In other words we have time zones ever heard of green whtch time zone. This way, time is calculated with respect to sunrise and sunset. \n\nThus its all depending on how sunlight reaches in ur region..!
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try these sites. They will answer any questions you might have.\n\nwww.msnbc.com/news/251727.asp\n\ncsep10.phys.utk.edu/astr161/lect/time/seasons.html\n\ncurious.astro.cornell.edu/question.php?number=196\n\nscience.howstuffworks.com/question165.htm
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The gravitational pull  of the planet tends to stop the atmosphere disappearing into space.\n\nAnother point is that tha atmosphere is never still, it is continually in motion due to the rotation of the planet and the heating and cooling from both the sun and the differences between the land/sea and the hotter.cooler parts of the planet.
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If you imagine a solar system that includes the sun and the Earth,and no other bodies, the Earth would travel about the sun in an ellipse (strictly speaking, the Earth and the sun would travel around their common center of gravity in ellipses).  An ellipse has two foci, which are points that define the ellipse in the same way that a point defines the center location of a circle.  Because the sun is so large and the orbit is so nearly circular, both of the foci lie near the center of the sun  So it is not correct to say that one of the foci is the sun -- both foci are in the sun, but they're really just mathematical points that define the shape of the orbit.\n\nWhen you add more planets to the mix, things get much more complicated, but one can think of each approximately elliptical orbit separately, and then there is a different set of foci for each pair of bodies if one neglects the influence of the other bodies.
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Approximately one rotation every 24 hours [grin].\nBut, seriously though, the Earth's radius (at the equator) is\n6380 km so the equatorial circumference is about 4 x 10^4 km,\nso the speed of the earth's surface (at the equator) due to the earth's\nrotation is 4 x 10^4 / 24 = 1700 km/hr.\nAs an exercise for the reader, compute the speed for your particular\nlatitude.\n\n1. What is the Sun's rotation speed around center of the galaxy? \n\nThe disk of our galaxy is flattened by rotation (just as the planet Saturn is flattened, and protostellar disks are flattened.) Individual stars in the disk are on nearly circular orbits in the plane of the disk, all revolving in the same direction around the center of our galaxy. (By contrast, stars in the halo are on elongated orbits, at random orientations, some traveling clockwise, and others counterclockwise.) \nThe Sun, for instance, a fairly typical disk star, is orbiting with a speed\nv = 220 km/sec = 0.000225 parsecs/year.\nThe radius of the Sun's orbit around the galactic center is\na = 8000 parsecs.\nThe circumference of the Sun's orbit is then\n2 pi a = 50,300 parsecs.\nThe orbital period of the Sun thus turns out to be\nP = 2 pi a / v = (50,300)/(0.000225) = 220,000,000 years. \n\n2. What is the speed of center of our galaxy?\nThe sun is about 26,000 light years from the centre of the milky way
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An equinox in astronomy is the moment when the Sun passes over the equator. The event occurs twice a year, around March 20 and September 23. The word equinox derives from the Latin word for equal night. The equinoxes are the two days each year when the middle of the Sun is an equal amount of time above and below the horizon for every location on Earth.
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First, the speed of the rotation of the earth relative to where you are on the earth.  At the equator, the circumference of the Earth is roughly 24000 miles.  This is convenient, because the Earth rotates about its axis once every 24 hours.  Therefore an hour = 1000 miles of equatorial rotation.  Understand the fastest moving part of the Earth is the equator, since an object on the equator travels 24000 around the earth's Axis every day.  If you are closer to the poles, you are on a "thinner" slice of the earth, where the circumferene may only be 20000miles.  In that case you are moving at 833 miles per hour.  The fact that the Earth moves faster at the Equator than at the poles is responsible for the Coriolus Effect which is really important to people who study meteorology, or who wonder why their toilets get all swirly when flushed.  Why we don't "feel" the rotation is, simply put, because we are rotating exactly the same way as the earth.  In physics, this is called a "frame of reference".  For most intents and purposes, the earth is at "rest" relative to us.  As a human, you make up part of the mass of the earth, and you spin with it in a constant rotation.  It's only when we look to things that are not directly connected to the earth that we really see the effects of it's rotation (ie Tides of water, moments of clouds and weather, etc. . .)  Hope that helps.
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I'm guessing ... a comet? Hale-Bopp or Halley's.\n\nguessing again .... sun and planets in a straight line?  or maybe Conjunction of four of the planets?\n\nCan I phone a friend? Ask the Audience? \n\nTry Google or Wikipedia with these: 'comet' or 'conjunction'.\n\n4th grade! Sheesh ... that's more like the $500,000 question on Who Wants To Be a Millionaire.  Even then, you get to choose one out of 4.
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The sun does not orbit the Earth (LOL).  The reason we have night and day is because it takes the Earth about 24 hours to rotate (spin).  Each time a side is facing the Sun, it is day, and when it is turned away it is in night.
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Look up "the nebular hypothesis".  you also are confusing the Milky Way (a disk shaped system of a hundred billion stars or so of which our sun is a part) and the Solar System (our sun and its surrounding planets and other assorted detritus.)\n\nhttp://en.wikipedia.org/wiki/Solar_nebula
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Why do you think rotation isn't a natural motion? Angular momentum is conserved, so when a gravitational collapse happens, the natural tendency *is* to rotate. The only exception would be a situation when everything was initially at rest (which wasn't the case). Also, why do you think all the stars rotate *in sync*? Each one is going in its own orbit with its own velocity. These velocities are not all the same by any means.
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Your friend is half right.  What keeps the earth in orbit is the gravitational pull of the sun.  Why doesn't the earth crash into the sun?  Because the inertia of the earth (or any other object in an orbit) is always at a right angle to the centripital force.  \n\nCentripital force is literally the center seeking force.  It is always directed to the of the orbit.  The velocity or direction of motion is always at a 90degree angle to this force.  Since the direction of motion and acceleration are always changing, the object can be constantly accelerating and constantly in motion without ever getting any closer to the center.
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Precession! The shape of Earth’s orbit becomes more or less oval (eccentricity), Earth wobbles as it spins (precession), and Earth's axis changes too (tilt). All these changes, over thousands of years, causes Earth's climate to change.
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You did meant to say "months" twice, right?  Because moths and months are slightly different things.\n\nAnyway, the difference is caused by how close the earth is to the sun (during its orbit around the sun.)  When the earth spins each day, it turns from day to night because the earth is facing the sun for half of the turn (roughly) and facing away for the other half (causing day and night.)  But depending on the orbit, the sun hits the earth differently.\n\nThe sun in fall and winter is more direct, I mean, like it hits you in the face.  It's, um, slanted differently.  But the light is weaker since the part of the earth that's having cold weather is tilted further from the sun.  Did I mention that the earth is tilted?  So that way, one hemisphere is tilted closer to the sun during one side of the orbit, and the other hemisphere gets the seasons during the opposite time of year (other side of the orbit.)  \n\nOK, like imagine that this percent mark % represents the northern and southern hemispheres.  Imagine that the % mark is traveling in a circle around a central sphere.  So on one side of the circle, the upper 0 is tilted toward the sun (spring and summer) and the lower 0 is on the other side of the tilted line and it's further from the sun.  But when the % gets to the other side of the circle, the *upper* 0 is on the far side of the tilted line and then the *lower* 0 is closer to the sun.  Which gives you seasons.\n\nI guess it gets lighter and darker faster because there's less clouds in fall and winter (it's colder, so there's less smog and haze and cloud cover in general) so dawn and dusk seem to happen faster.  Plus, there's less light and heat in general.  \n\nI hope that made sense.  The % thing makes sense to me, but if it doesn't, then make yourself a 3D model and see if it makes sense.
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Orbital obliquity is probably influenced by the sun in some way during the time when the planets were forming, but I don't think we have any solid idea exactly what factors were involved.  It's clear that most of the planets' axis are more or less vertical, though Venus in fact rotates the opposite way (so its obliquity is considered to be nearly 180 degrees).  The big exception is Neptune, which is nearly lying on its side.\n\nIf the Earth was similarly lying on its side as you suggest, then yes, it could spin the same and have light and dark "sides" that only change as it moves around the Sun.  See Neptune for details of this exact mechanism.
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The path of the apparent motion of the sun is called ecliptic.\n\nThe lunar orbit is at angle of 5 degree 8 minutes to the ecliptic.\n\nThe two points of intersection of the lunar orbit and ecliptic are called the nodes.\n\nThe sun comes to the same node every 346.6 days.\n\nHence it is clear that the sun goes to north and south directions  with respect to the moon also.