 Chuck Yeager was the first to break the sound barrier in the X-1. In October 1947, he reached 1,100 km per hour. We used Mach numbers to signify the multiple of the speed of sound a vehicle travels. This was Mach 1.06. The Lockheed SR-71A Blackbird set the current world's record for jet aircraft at 3,530 km per hour in 1976. That's Mach 3.3. The fastest rocket-powered manned aircraft was the X-15. It set the record at 7,258 km per hour in 1967. That's Mach 6.7. To graph the speeds these cars and aircraft have achieved, we'll need to adjust the units on the X-axis again. This time, we'll make each interval on the X-axis equal to the distance sound travels in air in one second. That's 341 meters. The line at 45 degrees that divides the area in half is the line that represents the speed of sound in air. We're now getting close to as fast as humans and machines can move. The last four we'll cover are all spacecraft. Apollo 10 reached 39,896 km per hour. That's 24,790 miles per hour. In 1969, as it paved the way for man's first landing on the moon. I remember watching this launch. The New Horizons spacecraft was launched in 2006, edit for Pluto. It is traveling at 58,536 km per hour. The record for unmanned spaceflight as measured relative to the Earth. It started sending back never-before-seen pictures of Pluto in July 2015. Helios A and Helios B are a pair of probes launched into orbit around the Sun in order to study solar processes. Launched on December 10, 1974 and January 15, 1976, the probes were notable for having set a maximum speed record for spacecraft at 252,792 km per hour. That's 157,077 miles per hour. But this speed is measured relative to the Sun, not the Earth. Note that the Earth's average speed around the Sun is 108,000 km per hour, or 67,000 miles per hour. But the current speed record, as of mid-year 2022, belongs to the Parker Solar Probe. On November 20, 2021, it reached a speed of 163 km per second. That's 586,800 km per hour, or 364,660 miles per hour, as it actually passed through the outer atmosphere of the Sun. It reached this speed after getting a gravity assist from Venus a month earlier. This is the first time in history a spacecraft has touched the Sun's corona, where it sampled particles and measured its magnetic fields. This record is expected to stand until September of 2023, when the probe will beat its own record on its 17th orbit of the Sun. At these speeds, we have to increase the distance intervals again. We'll set it at 10 km per mark. That's 6.2 miles. Parker is moving over 40 million times faster than the snail in my backyard.