physics.basic_orbital_capture
=============================

.. py:module:: physics.basic_orbital_capture

.. autoapi-nested-parse::

   These two functions will return the radii of impact for a target object
   of mass M and radius R as well as it's effective cross sectional area sigma.
   That is to say any projectile with velocity v passing within sigma, will impact the
   target object with mass M. The derivation of which is given at the bottom
   of this file.

   The derivation shows that a projectile does not need to aim directly at the target
   body in order to hit it, as  R_capture>R_target. Astronomers refer to the effective
   cross section for capture as sigma=π*R_capture**2.

   This algorithm does not account for an N-body problem.



Functions
---------

.. autoapisummary::

   physics.basic_orbital_capture.capture_area
   physics.basic_orbital_capture.capture_radii


Module Contents
---------------

.. py:function:: capture_area(capture_radius: float) -> float

   Input Param:
   ------------
   capture_radius: The radius of orbital capture and impact for a central body of
   mass M and a projectile moving towards it with velocity v
       SI units: meters | m
   Returns:
   --------
   >>> capture_area(17209590691)
   9.304455331329126e+20
   >>> capture_area(-1)
   Traceback (most recent call last):
       ...
   ValueError: Cannot have a capture radius less than 0

   Returned SI units:
   ------------------
   meters*meters | m**2


.. py:function:: capture_radii(target_body_radius: float, target_body_mass: float, projectile_velocity: float) -> float

   Input Params:
   -------------
   target_body_radius: Radius of the central body SI units: meters | m
   target_body_mass: Mass of the central body SI units: kilograms | kg
   projectile_velocity: Velocity of object moving toward central body
       SI units: meters/second | m/s
   Returns:
   --------
   >>> capture_radii(6.957e8, 1.99e30, 25000.0)
   17209590691.0
   >>> capture_radii(-6.957e8, 1.99e30, 25000.0)
   Traceback (most recent call last):
       ...
   ValueError: Radius cannot be less than 0
   >>> capture_radii(6.957e8, -1.99e30, 25000.0)
   Traceback (most recent call last):
       ...
   ValueError: Mass cannot be less than 0
   >>> capture_radii(6.957e8, 1.99e30, c+1)
   Traceback (most recent call last):
       ...
   ValueError: Cannot go beyond speed of light

   Returned SI units:
   ------------------
   meters | m