Clue 1: BackgroundImagine that you live on the planet Zog, in a far away universe that is nothing like our own.

Zog is much like the Earth, and all the laws of physics on Zog appear to be the same as the laws on Earth. The inhabitants of Zog have all the same technologies and telescopes that we do on Earth today.

ZOG'S SOLAR SYSTEM

Zog does not have a moon, and is the only planet in its solar system.

It orbits a star that looks much like our Sun, but with one difference - close in to Zog's sun is a very small blue star, orbiting very rapidly around Zog's sun. You can see this small blue star close to the Sun in the image below - sunset on Zog:

THE NIGHT-TIME SKY

By day, the sky looks pretty similar to Earth's sky. But by night, things are quite different. Here is a typical night-time view:

As you can see, the sky is dominated by brilliantly coloured bubbles! These are the brightest objects in the night-time sky. Some are large, extending over angles of many degrees, while others are small. Tens of thousands of bubbles are visible to the naked eye, while many more are revealed by telescopes. They appear to be randomly distributed across the sky.

These bubbles have fascinated the inhabitants of Zog since the dawn of recorded history. Some cultures worship the brighter ones, while others group them into fancyful shapes named after their mythical ancestors. Even today, many of the less educated citizens of Zog believe that the positions of the bubbles in the sky determine the fate of their lives on Zog. Philosophers have speculated that they are crystal spheres, water bubbles or shells of gas.

In addition to the bubbles, some point-like dots of light (also known as stars) are seen. They are rarer and fainter than the bubbles. These "stars" seem to come in two types. The most common are white stars - similar in colour to Zog's sun. Philosophers speculate that these are indeed stars like the Sun, but much more distant. Around 2000 of these white stars are visible to the naked eye. In addition, there are around 500 stars which show red colours.

Read the first clue. It should give you some ideas for future research, but nothing like enough information to deduce anything definitely.

You should then try to figure out some sensible observations which might help you figure out what is going on here. Discuss these on the discussion board. You might want to come up with some speculative ideas ("hypotheses") and work out how you might test these.

Next week we will post some of the data you requested, and another clue.