Radial velocity Radial velocity The radial velocity of an object with respect to a given point is the rate of change of the distance between the object and the point. That is, the radial velocity is the component of the object's velocity that points in the direction of the radius connecting the object and the point. In astronomy, the point is usually taken to be the observer on Earth, so the radial velocity then denotes the speed with which the object moves away from or approaches the Earth. In astronomy, radial velocity is often measured to the first order of approximation by
To be, or not to be suffer<br> The slings and arrows of outrageous fortune,<br> Or to take Arms against a Sea of troubles,<br> And by opposing end them: to die, to sleep<br> No more; and by a sleep, to say we end<br> The heart-ache, and the thousand natural shocks<br> That Flesh is heir to? 'Tis a consummation<br> Devoutly to be wished. To die, to sleep,<br> To sleep, perchance to Dream; aye, there's the rub,<br> For in that sleep of death, what dreams may come,<br> When we have shuffled off this mortal coil,<br> Must give us pause. There's the respect<br> That makes Calamity of so long life:<br>