I wish Bobby and his family a very Happy New Year! See you in 2016.

I was so happy to be able to participate in Bobby's birthday today! For our class, Bobby very sweetly asked if he could go play basketball with his friends, so of course I consented. They all had a very good game! It's the first time I've seen Bobby play - I'm impressed! After that he engaged in a chess game with Ethan. Happy Birthday, Bobby!

Gwendolyn has worked so hard this semester, so I thought to wrap the year up with some games. Gwendolyn chose Hangman, and so we played the game for much of the hour. Whenever there was an object Gwendolyn didn't know, I'd explain to her what it was. She also colored in a shuttle in space in the most dramatic colors - I loved her choice of colors!

Bobby explored an online interactive game that allowed him to understand the relative masses of the planets. You can pick a planet and place it on one side of a balance scale, and then fill the other side with multiples of smaller planets. It became quite evident to him how massive Jupiter actually is when he realized he would have to fill the other scale with 100,000 Plutos!

We finally got round to exploring one of the Astronomy Picture of the Day posts that I've been meaning to get to for a long time. This is an interactive animation that allows one to scroll either up or down in size from the size of a human. The two extremes are Planck length, or the smallest measurement of length that has any meaning (anything smaller and quantum effects rather than classical gravity effects dominate), and at the other end of the scale, the extent of the observable universe. In numbers, this goes from 10^(-35) m to 10^27 m. Along the way we see, amongst other things, quarks, atomic nuclei, bacteria, insects, animals, countries, asteroids, planets, stars – from dwarf stars to supergiants, galaxies, clusters of galaxies.

During the Dark Ages in Europe when all things science were pretty much forgotten or left in obscurity, the Arabs kept up – and progressed with – the astronomical studies practiced by the ancient Greeks. These Arabic scientists recorded their observations meticulously, and in the process gave many of the brightest stars Arabic names in lieu of their Greek names. With the advent of the Renaissance and the return of scientific enlightenment to Europe, when European astronomers picked up where the Arabs left off, they continued with the Arabic names bestowed upon the stars. Consequently, to this day, we still call many of the stars by their Arabic names, e.g. Dubhe, Rigel, Betelgeuse, Mizar. These names often refer to physical elements of the constellation, for example 'the knee of the giant', or 'the back of the bear'. In today's class, we looked at the English translations of many of these names.

After celebrating Jackson's birthday at lunch, the kids were all quite wired, so for the last class of the week, they had an ice cream and rope-jumping session. Bobby is always so polite when he asks permission to do something.

Following up on a discussion I had had earlier in the day, I thought it might interest Bobby to see that all the other major planets of the Solar System when lined up, diameter to diameter, can fit within the Earth-lunar orbit. I'm going to use this as a springboard to start collecting hard facts on the planets, and expanding on the model Solar System in the school corridor. We concluded with Bobby's favorite activity: browsing through the archives of Astronomy Picture of the Day in search of images of galaxies and other cool objects. Today, Bobby discovered the nucleus of the active galaxy Centaurus A, a very cool object indeed.

It was so nice to see Gwendolyn again today! Since she has changed rooms, we transferred the two constellations – The Big Dipper and Canis Major – from her old room to the new one. We also looked at a set of glow-in-the-dark Solar System planets that Gwendolyn had, and then compared them to the distance-scale model that Bobby installed in the corridor. In addition, I happened to notice a vocabulary list on Gwendolyn's table that had words starting with the prefix 'anti-', and one of the words was 'antimatter' – so I took the opportunity to tell her a bit about the Big Bang and about atoms, and matter vs. antimatter.

In today's class Bobby and I assembled a star wheel that was kindly offered by Sky & Telescope online. We spent most of the class understanding how the star wheel works, and how one can use it to locate objects in the night sky. We also looked at star charts, and compared them to the star wheel. I gave Bobby a list of objects he can try to look for using binoculars now when he goes up to New York, since it gets dark so early at this time of the year. Certain objects, such as the Pleiades and the crescent moon are quite stunning binocular objects.