Practical Exercise 1:

Arrange to following spatial objects according to their distance from the Earth starting from the smallest to the biggest. If you have an Internet connection, try to determine the distances.

ISS, Polaris, Jupiter, M31 Galaxy in Andromeda, centre of our Galaxy, NGC 4414 Galaxy in the constellation of Coma Berenices, Moon

Answer: ISS (approx. 400 km, i.e. 0.0013 light seconds), Moon (384 000 km, i.e. 1.3 light second), Jupiter (5.2 au, i. e. 2600 light seconds, 43 light minutes), Polaris (approximately 400 ly), centre of our Galaxy (30 000 ly), M31 Galaxy in Andromeda (approx. 2.5 million of ly), NGC 4414 Galaxy in the constellation of Coma Berenices (approx. 60 million of ly).

The numbers in various scales are indicated in various units (km, ly) and it would be suitable to use only one for comparison (e.g. light seconds, minutes and years). For some objects, e.g. Polaris, the distance value is not exact and a range is often stated in the literature. If we have more time available, we can search for the weights of these objects. The activity can be supplemented by projecting a video or an animation (e.g. Huang, C. The Scale of the Universe 2 or Obreschkow, D. Cosmic Eye).