What is Escape: Definition and 372 Discussions

Atmospheric escape is the loss of planetary atmospheric gases to outer space. A number of different mechanisms can be responsible for atmospheric escape; these processes can be divided into thermal escape, non-thermal (or suprathermal) escape, and impact erosion. The relative importance of each loss process depends on the planet's escape velocity, its atmosphere composition, and its distance from its star. Escape occurs when molecular kinetic energy overcomes gravitational energy; in other words, a molecule can escape when it is moving faster than the escape velocity of its planet. Categorizing the rate of atmospheric escape in exoplanets is necessary to determining whether an atmosphere persists, and so the exoplanet's habitability and likelihood of life.

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  1. S

    How do particles behave when approaching a black hole?

    Most neutrinos move straight through the Earth without colliding, right? Imagine a very small particle that moves against a black hole. it cannot move straight through it without colliding or collapsing. If it does not collide then it can never have a starting speed against the black hole...
  2. Ivan Seeking

    Escape from the Universe: Michio Kaku

    http://prospectmagazine.co.uk/article_details.php.6701.html
  3. C

    What is the escape speed of a projectile fired from Earth's surface at 8.2 km/s?

    A projectile if fired vertically from Earth's surface with an initial speed of 8.2 km/s. Neglecting air drag, how far from the survace of Earth will it go? Well, I know that the escape speed of Earth is 11.2 km/s. how would i go about solving this?
  4. D

    Solving Escape Velocity of the Sun: Troubleshooting an Error

    I can't seem to obtain the right answer using the escape velocity formula. I think my problem is with the gravitational constant. I would like to find the escape velocity of the sun. v_e=\sqrt{\frac{2GM}{r}} or v_e=\sqrt{\frac{2\mu}{r}} v_e_\odot=617.54(km/s)...
  5. C

    Calculating the Escape Velocity from a Neutron Star

    Question: The radius of a neutron star is 750 times smaller than the Earth's radius, and its mass is 1.8 times larger than the Earth's mass. What is the escape velocity from the surface of a neutron star? (Ignore the fact that, at high speeds, one should not really use mv^2/2 for the kinetic...
  6. E

    What is the Escape Speed Formula and How Do I Use It to Solve Problems?

    problem: Taking the potential energy to be zero at infinite separation, find the potential energy of a 118.0-kg object at the surface of the earth. (Use 6.37E+6 m for the Earth's radius.) I did this and got -7.374E09. It then asks Find the escape speed for a body projected from this...
  7. T

    Escape velocity from center of earth

    How would one go about calculating the escape velocity of an object with mass m from the center of the Earth. I understand that that when launched from the surface of the Earth, mechanical energy is conserved and you end up with v escape =sqrt[2gRe] So what i did was i calculated what i...
  8. C

    How can I calculate the escape velocity of a projectile from a planet's surface?

    I've been thinking about this for a while now, and I was wanting to know what you guys think. The problem states: Show that a projectile with mass "m" can escape from the surface of a planet if it is launched vertically upward with a kinetic energy greater than MgR, where R is the the planet's...
  9. M

    What is the required energy for a projectile to escape Earth?

    I have a 3 part question, and I have managed to get 2 of the three parts, but I can not figure out the 3rd for the life of me. A projectile is shot directly away from Earth's surface. Neglect the rotation of Earth. (C) What is the least initial mechanical energy required at launch if the...
  10. tony873004

    What is the formula for calculating delta v for escape velocity?

    Let's say I have an object orbiting the Sun in a circular orbit with an orbital velocity of 30 km/s. If I want to accelerate prograde into a hyperbolic orbit, and I'd like my velocity relative to the Sun to be 1 km/s at infinity, what is the formula I'd use to figure out how much delta v in the...
  11. Cyrus

    Escape velocity and gravitation

    Hi, me again. I have another question concerning the gravitation equation. My physics book shows through a proof that the escape velocity of an Earth satelite is just sqrt(2) greated than the orbital velocity. But I am having trouble seeing how this is so. My instinct tells me that if I increase...
  12. R

    Escape velocity outside event horizon

    Escape velocity at particular radius from the gravitational source means the initial speed that an object needs at that raduis in order to coast without limit ("to infinity") without ever falling back to the gravitational source. If the escape velocity at a radius is so large that nothing...
  13. E

    Escape Velocity from Solar System

    Here is a celestial mechanics problem I can't seem to solve:To escape the solar system, an interstellar spacecraft must overcome the gravitational attraction of both the Earth and Sun. Ignore the effects of the other bodies in the solar system. Show that the escape velocity is v =...
  14. S

    Why is the escape velocity of Earth so fast?

    Help me understand this please. Why is the escape velocity of Earth so fast? Doesn’t the gravitational pull of the Earth weaken as you get farther away from the center of the Earth? I can jump a couple feet into the air… I’m am going upwards nowhere near 27k miles an hour… if I could...
  15. P

    Why is the escape velocity for a black hole impossible to achieve?

    What is the reason why something, once it enters the event horizon of a black hole, it cannot escape? I've often heard the answer given that at the event horizon the escape velocity equals the speed of light, and from within the horizon a superluminal velocity is required, which is impossible...
  16. E

    Possible for electrons to escape this speed limit.

    I seen times in general physics book for sections with problems concerning the electron that their speeds in some answers come above that of speed of light... I wonder if this is a common recurring mistake or if it is possible for electrons to escape this speed limit.
  17. D

    Question about Grav. Potential Energy and Escape Velocity

    I am finding this question to be a bit challenging--- Determine a formula for the maximum height h that a rocket will reach if launched vertically from the Earth's surface with speed Vo. (< Vesc) (Ignore air resistance and the Earth's rotation) I know I should plug in numbers only until...
  18. G

    Energy Conservation and Escape Velocity

    If a particle is launched with kinetic energy as it gets further from the mass (eg a planet) the kinetic energy decreases. However Potential Energy GMm/r also decreases the further you get from the mass. Where does all this energy go? :confused: Granted, the calculation U + K = 0 does give...
  19. S

    Escape velocity and formulas for circular orbits

    In my class, we developed a list of formulas for circular orbits. One of them is E/m=1/2v2-GM/r=constant. To derive escape velocity we find for what v does E=0. But an orbit of this nature is certainly not circular! How can we apply the formula?
  20. C

    Escape velocity and acceleration from gravity

    Ive heard that the escape velocity of a body is the same as the maximum velocity that can be achieved from gravitational acceleration from the same body. Like say it requires a spacecraft to be moving at about 11 km/sec to escape Earth's gravity, and we isolated the Earth and spacecraft , so...
  21. Shirley

    Does Gravity Affect Light in Stars?

    First, let me thank you in advance for your patience. I understand there is a lot of foundation I need to build before I can truly learn much of what I need to know, and I thank you for your assistance. We know that gravity is strongest closest to large objects. Gravity seems to effect...
  22. R

    Escape Velocity of virtual particles

    I know that the escape velocity for virtual particles being emitted from black holes is c2+ (in the black hole entropy formula, there is an escape velocity of c3). I also know that Hawking radiation and for that matter*(I don't mean matter in physics terms), any radiation being emitted from a...
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