Comet Definition and 154 Threads

Homework Statement A comet revolves around the sun in a closed elliptical trajectory. Ignore any force acting upon it besides gravity. Prove that the angle between the position vector (sun in the origin) and the velocity vector of the comet at its perihelion and aphelion is 90º. The...

Visiting New Scientist website the following time lapse movie caught my eye, see, http://www.newscientist.com/article/dn24667#.Upe1pNJwq0I from, http://www.newscientist.com/ I get the emissions from the sun, the stars, and the comet, but what is in the movie that kind of looks like...

Hi folks, Had an idea for a science fiction story I'm writing, wondered if it would actually work in reality. Basically, if a comet's nucleus were comprised of concentric layers of ice and dust, would it produce a coma/tail in an on-and-off manner? Would it outgas and stop, outgas and stop...

1. The problem statement a comet gets in the way of the Halley asteroid, so the question is: what's the new trajectory of the asteroid (its excentricity, its orbital rotation and it perihelion, aphelion) both objects have same mass and we suppose that the comet have an negilgeable...

What is happening with Hyperbolic Comet C-2012 S1 (ISON)? It is going to crash into the Sun at the end of Nov. Was it downgraded from a Comet? Here is a site that used to track it: http://www.heavens-above.com/Comets.aspx?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET I should be big in the...

The popular press has been alive lately with stories of asteroid interception and even asteroid recovery. Has there been any thoughts of a spacecraft closely approaching a comet? How big are they? How fast do they travel? Is it remotely possible using existing technology? Could we land on...

How does Jupiter "protect" Earth from comets and such? I've commonly heard that Jupiter protects Earth by flinging comets out of an orbit that would otherwise leave them heading for Earth. I understand that Jupiter can throw comets and other objects out of their current orbit when they pass by...

Homework Statement The problem and its solution are attached as TheProblemAndSolution.jpg. Homework Equations *The (“instantaneous”) dust tail is opposite the direction of motion. *The plasma tail is oppositely directed to the star in question (at all times). The Attempt at a Solution...

Recently, I attended a lecture at my university entitled "The Life and Death of a Star-Grazing Comet" presented by John Raymond, an astrophysicist at Harvard Smithsonian. In this lecture, he talked about Comet Lovejoy and how it allowed us to help study the corona of the sun. As the comet was so...

Homework Statement Comets move around the sun in very elliptical orbits. At its closet approach, in 1986, Comet Halley was 8.79 x 10^7 km from the sun and moving with a speed of 54.6 km/s. What was the comet's speed when it crossed Neptune's orbit in 2006? Homework Equations Mv1r1=Mv2r2...

I am wondering about the journey of a comet: 1. Let's say this comet is located in the Kuiper Belt. From my understanding it is inert. Trying to tie in my limited Relativity understanding, could I say that it is in free float? From my understanding, it is getting its movement orders from...

Hey all, I haven't been alive for that long, so I guess my data probably isn't as good as it should be, but in my experience there have been far more noteworthy comets appearing only to the southern hemisphere, and not to the northern one. In fact, I haven't ever seen a comet (since I was a...

First post...Hi everyone. Now that the Chelyabinsk meteor has been determined to be 700,000 tons and 56 feet in diameter, is there anyway of "guesstimating" how much inbound comet C/2013 A1 would weigh at approximately 50 kilometers in diameter? Also when would/could the final trajectory be...

In November 2013 the comet Ison will be visible , spectacular, brighter than the moon: http://Earth'sky.org/space/big-sun-diving-comet-ison-might-be-spectacular-in-2013

Comets travel around the sun in elliptical orbits with large eccentricities. If a comet has speed 2.5×104 when at a distance of 2.3×1011 from the center of the sun, what is its speed when at a distance of 5.9×1010 . Using Kepler's Law T2 is proportional to R3 T2/R3 is a constant (C)...

I've gotten into an amusing discussion with another individual on the topic of the apparent size of comets as seen in SOHO satellite images of Sungrazing or Sun-impacting comets. I won't go into the crackpot conspiracy theories I've heard, but will instead ask: why do these tiny comets appear so...

Homework Statement A comet is traveling towards the earth. The comet has a mass of 4.80E+12 kg and a radius of 385 m. The comet is traveling with a speed of 19 km/s and spinning with a period of 0.12 seconds when its center is a distance 1.88E+7 m away from the center of the earth. The comet...

Please see attatchment for qs. I really need help with number two mostly.

Suppose a large, 'dirty snowball' comet, 25-50km in diameter or more, were to hit Mars at some speed, say 75,000 km/h. I am quite certain it would vapourize on impact. And the impact will create super-heated high-velocity shock waves which will travel around Mars at least once, probably...

If there is Dark Matter in the solar system, the erosion of comet with Dark Matter will be happen? A comet's main component is water, water has many nucleus per unit volume. and comet speed is very high. So. comet has high collision frequency with Dark Matter per time. Total energy for the...

Homework Statement Consider the extreme case that the comet is released from rest at a distance R_max from the sun. In this case L is actually zero. Use the technique described in connection with 4.58 to find how long the comet takes to reach the sun. The radius of the sun for now is zero...

Hi there, So I'm curious to know if it might be possible for an object of sufficient size/mass to, when upon impact, hit with enough force to cause the planets atmosphere to diminish. It's less than a month now until the MSL reaches Mars...I'm pretty pretty excited :|

I was just reading up about Halley's Comet in Wikipedia ( http://en.wikipedia.org/wiki/Halley's_Comet"]http://en.wikipedia.org/wiki/Halley's_Comet[/PLAIN] ), and I came across the following two items: "The possibility has been raised that 1st-century Jewish astronomers had already...

A comet near the sun whose orbit is________ would never be near the sun again is called what? My options are elliptical (I know its not this one), circular, hyperbolic, apogee, and following an inverse square law.

Hello. I read from a calculus book (Larson) that shape of comet's orbit is determined by its velocity in following way. Ellipse if v < sqrt(2GM/p) Parabola if v = sqrt(2GM/p) Hyperbola if v > sqrt(2GM/p) where p is the distance between one vertex and one focus of the comet's orbit...

Are there other comets like hally (periodic phenomena's?)

Homework Statement A comet of mass m moves in a parabolic orbit in the ecliptic plane (the plane of Earth’s orbit), so its perihelion distance ρ (its closest distance to the Sun) is less than Ro (the orbital distance of the Earth around the Sun) and occurs when θ = 0 for the comet. (The...

Hi everyone: I have trouble in an assignment I was given. The instructions are to utilize Runge-Kutta order 2 and 4 to determine the period of the comet Halley (perihelion = 0.586 AU and aphelion = 35.1 AU). The period of the orbit is given by Kepler's third law: Period = Sm3/2 where...

Homework Statement If a comet passes close to the Earth with a velocity of 38km/s, how far is the apocentre of its orbit from the Sun? What is the eccentricity of its orbit? Homework Equations Vis-Viva Equation: (V)_{ecc}^{2} = GM [ \frac{2}{R} - \frac{1}{a} ] Apocentre distance...

This YouTube describes the Rosetta mission Here is the print version: http://science.nasa.gov/science-news/science-at-nasa/2012/02feb_rosetta/ Rosetta is a European (ESA) mission with some Usa instruments on board. It carries a lander that will descend onto the comet surface, take pictures at...

Homework Statement A comet is approaching the Sun from a vast distance with velocity V. If the Sun exerted no force on the comet it would continue with uniform velocity V and its distance of closest approach to the Sun would be p. Find the path of the comet and the angle through which it is...

Comet's Death Dive Into Sun Seen in Detail for 1st Time http://www.space.com/14288-sungrazing-comet-death-dive-sun-observed.html by Charles Q. Choi, SPACE.com Contributor Date: 19 January 2012 I was surprised to learn that sun-diving comets are common. I guess in the past, sun-diving comets...

http://science.nasa.gov/media/medialibrary/2011/12/16/lovejoy_c3_anim2.gif http://spaceweather.com/ <--- archive December 17, 2011 In a rare curiosity of nature, Comet Lovejoy appears to transit the elevated temperatures of the solar corona, laughing off the sizzling encounter, seemingly even...

A binary star system has two stars, each with the same mass as our sun, separated by 1.6x10^12 m. A comet is very far away and essentially at rest. Slowly but surely, gravity pulls the comet toward the stars. Suppose the comet travels along a straight line that passes through the midpoint...

Homework Statement As Halley’s comet orbits the sun, its distance from the sun changes dramatically, from 88700000000 m to 5614000000000 m. If the comet’s speed at closest approach is 53430 m/s, what is its speed when it is farthest from the sun if angular momentum is conserved...

I've been researching this for a while now, and none of the theory's can predict it. I've studied comets for a while now, and the tails come out of the front and then has a weird curve which goes to the back. If you guys have any random ideas or thoughts of why this is happening, that would be...

Homework Statement A comet from the Oort cloud, with perihelion 6AU, is perturbed by Saturn into an orbit with perihelion 4AU. What is the semi-major axis and eccentricity of the new orbit? Homework Equations Perihelion = a(1-e) The Attempt at a Solution hey i could really...

I have read a few times that comets are significant transports of ice (perhaps in having supplied water to fill Earth's oceans). That implies that water is more abundant in the few comets (in accumulated mass) that have impacted Earth than that which would have existed within the initial planet...

Interesting question to think about. We know that there are lots of comet bodies in the Oort cloud and we know that even in the near absolute zero temperatures evaporation does take place. Comets are usually covered in dust, which slows down this evaporation, but let's consider clear body...

Homework Statement At its perihelion in February 1986, Comet Halley was 8.79x10^7 km form the Sun and was moving at 54.6 km/s. What was its speed when it crossed Neptune's orbit in 2006? Homework Equations K0+U0=K+U The Attempt at a Solution I know I need to do this using...

Homework Statement Find eccentricity for: a comet with mass 1.2x1010kg moves in an elliptical orbit around the sun. Its distance from the Sun ranges between .5AU and 50 AU. Homework Equations The Attempt at a Solution I drew it out to try and viualize it and i know eccentricity...

Homework Statement Use the information in Section A.3 and the data in Table A.19 to calculate the heliocentric radial distance (in AU) of Comet Halley at 12h UT on July 16, 1994. - Done, Section A.3 just talked about finding dates using Epochs and such. Table 19 had comet details which will...

Homework Statement I'm trying to find out the mean motion of Halleys Comet using the equation. n = \sqrt{\frac{GM}{a^3}} where we have taken the mass of Halleys comet to be negligible compared to the sun, M is the mass of the sun and a is the semi major axis. The Attempt at a...

..are here Amazing (Credit NASA)

Homework Statement Suppose that a comet that was seen in 545 A.D. by Chinese astronomers was spotted again in year 1937. Assume the time between observations is the period of the comet and take its eccentricity as 0.11. What are (a) the semimajor axis of the comet's orbit and (b) its greatest...

why does the moon keep rotating about its own axis? especially after so many comets have hit it?

1) A huge meteor can cause to destroy the civilization. But let assume that a comet pass by the Earth. Can a comet cause such a big destruction without collision? 2) Let assume that a comet collide with the Moon. This situation can cause such a big destruction on the Earth? 3)...

Homework Statement Halley’s Comet passed perihelion on 9 February 1986. It has a semi-major axis a = 17.96 AU and eccentricity e = 0.9673. (One astronomical unit (AU) is the distance between the Earth and the Sun.) Calculate the period of Halley’s Comet and the approximate date on which you...

Homework Statement Period of Halley's comet is 76 years. It comes very close to teh surface of the Sun on its closest approach. How far out from teh Sun is it at its farthest?Homework Equations - since no semimajor/minor axes data given: assume circular orbit. - Earth orbit about Sun is: 1.496...

This was shown in a textbook about the two body problem, and they compared it to the energy potential of two atoms, but the sun and comet don't experience charge so that 'when it gets too close the nuclei repel each other'. It mentioned something about centrifugal force, but I don't understand...