Spark and Perl go looking
Craters.
Craters on craters.
Craters on the craters on the craters.
You will run out of counting.
Why has the shiny one next door got hardly any?
Europa. Its surface keeps renewing itself: the ice cracks, water comes up, and freezes over again.
This one never has.
So it kept everything that ever happened to it.
Every single knock. Every asteroid.
It is the oldest face we know of.
All those dents mean it is rock, surely.
Ice takes a dent.
…So the oldest face in the solar system is written in ice.
And it holds a mark just as well as stone would.
Ice, and every mark kept.
Find Jupiter first. Callisto is usually the dot furthest out.
Whenever Jupiter is up.
Where to find Callisto, and when
Where the Earth is clear, it climbs high in the sky. The darker it gets, the lower it stays. Where it is black, it never comes up. No shading at all: it does not matter where you live.
What do I need to see Callisto?
Binoculars with 10× magnification show it, if you rest them on a fence or a wall.
A 150 mm telescope is what shows it properly.
Could you stand on a planet or moon?Eyes, binoculars, or telescope?Which one does not belong?
Space
Could you stand on a planet or moon?
Read on
Go and look