Astronomy no longer recognizes the "music of the spheres". Yet if heavenly bodies did make music, perhaps there are those who could hear it! Read about some individuals who've pursued astronomy and music in their different ways.

Galaxies and star clusters are collections of stars held together by gravity. Galaxies are really big. But how big is big? Even bigger than a million stars? Yes. A million is small in astronomy.

What were the big astronomy events of 2013? Here are my top ten choices and they include a big bang over Russia, a Moon goddess and Jade Rabbit, a telescope in the high Andean desert to look for the first galaxies, and the launch one of the most ambitious space missions ever.

Constellations and asterisms are both patterns of stars. So what is a constellation? And If Saturn is in the constellation Virgo, has it left the Solar System? Why is the Big Dipper an asterism and not a constellation?

Did you know that there is a unicorn constellation? Certainly Monoceros isn't a classical constellation, and it's almost too faint to see. But it has a lot of interesting stars and other objects in it.

In the Harry Potter books there are a number of characters that are named for stars and constellations. You can find out more about these stars - and for those that don't know the books, there's a bit of background on the characters.

People once thought that stars were eternal and unchanging. Today we know that they have life cycles of birth and death. Here is the story of how a star like our Sun is born.

Jupiter has at least 79 moons. Some of them are only half a mile long, but one is bigger than the planet Mercury. Which moon has hundreds of volcanoes, and which one has a deep ocean under an icy surface? Find out here.

When a rare planetary alignment opened up the outer Solar System, Voyager 1 was sent forth. It observed the gas giants Jupiter and Saturn and their moons. At nearly 4 billion miles from the Sun, the probe turned and took one last picture of home before continuing its journey to the stars.

If you think being an astronaut is a glamorous occupation, Mary Roach's book “Packing for Mars” will bring you down to Earth. Playing in free-fall looks like fun, but without gravity, eating, hygiene and dealing with waste are not fun. Here's the lowdown. Still want to go to Mars?