Traditional active radars transmit a powerful electromagnetic pulse and record the echo’s delay time and power to measure target properties of interest, such as range, velocity, and reflectivity. Such observations are critical for investigating current and evolving conditions in extreme environments (i.e., polar regions and planetary missions); however, existing radar systems are resource-intensive in terms of cost, power, mass, and spectrum usage when continuously monitoring large areas of interest. I address this challenge by presenting a novel implementation of passive radar that leverages ambient radio noise sources (instead of transmitting a powerful radio signal) as a low-resource approach for echo detection, ranging, and imaging.