View full lesson: ed.ted.com/lessons/a-trip-through-space-to-calculate-distance-heather-tunnell Imagine two aliens racing across outer space to their moon. Who can we deem the fastest alien? With DIRT -- or the equation Distance = Rate x Time -- we can calculate their rates, using the distance they traveled and the time they took. Heather Tunnell explains how to use this helpful equation to determine which of our alien friends is truly faster. Lesson by Heather Tunnell, animation by Karrot Animation.