My five-year-old is obsessed with size comparisons of planets, stars, and larger and smaller astronomical objects (as well as structures on earth). His interests have expanded greatly my own knowledge of astronomy. At first I thought it would be interesting to buy a telescope and play with that, but there isn't much to see with a cheap telescope, and the hobby gets quite expensive if one really wants to directly observe interesting objects (besides the moon). We have gone to the local observatory/planetarium and will return there. Both the three-year-old and the five-year-old enjoyed it immensely. However, looking at the Galilean moons was largely a disappointment, even from the professional telescopes available on the public viewing nights. One gets about five seconds to focus one's eye enough. I wasn't even sure the children saw the objects.
Astronomy without a Telescope
That said, astronomy is readily available through photos and videos and a multitude of "size comparison" videos found on YouTube (which is otherwise restricted for the children). Here are some fun facts that surprised me, and fascinate the children:
There is so much fantastic information and so many images on the NASA website, and especially what we get from the Hubble Space Telescope which we cannot see without it (for example, into the ultraviolet spectrum).
- The universe is 13.8 billion years old.
- Because of this we can only see so much of the universe, both in terms of distance (only that which is less than 13.8 billion light years away or closer), and time (we only see the past due to the lag of light).
- There are estimated 70 sextillion stars in the universe, though only about 4,500 would be visible to the naked eye, and many fewer due to light pollution.
- There is a supermassive black hole at the center of the Milky Way galaxy, some 16,000 light years away.
- Dwarf planets
- Gravity and mass and effect on jump height for an astronaut.
Composite image of radio data from the Milky Way galactic center