I really enjoy my work. Part of what I do puts me in situations where I learn new things and more about topics I thought I already understood. It is the second part of that sentence that tends to humble me fairly often.

When I talk to kids about space, I often tell them we know about this much about space, as I hold my fingers close together, and that there is this much to know, as I spread my arms out as far as I can.

As I walked out of a recent meeting, I began to think about how it is easy to become impressed with what we think we know when the simple fact is that there is so very much more to understand. We are separated from our students’ level of understanding by a very thin margin.

This year, we celebrated the 50th anniversary of the Apollo moon landing. While it is easy to focus only on Apollo 11, this celebration of human achievement actually began in a somber way when we commemorated 50 years since the loss of the Apollo 1 crew, which occurred back in January of 1967. We moved on to remembering the first manned Apollo 7 mission from October 1968, and the audacious Apollo 8 flight to the moon in December of that same year. Apollo 9 cleared the way by testing the lunar lander in Earth orbit in March of 1969. Apollo 10 proved our ability to rendezvous in lunar orbit in May, which all led to the big event on July 20, 1969 when humans first set foot on the moon.