The Zodiacal Light

The zodiacal light is caused by sunlight reflecting from meteoric dust that orbits the sun in the plane of the solar system, remnants of the vast nebula of dust and gas out of which the solar system was born more than four billion years ago. Like the planets, this diffuse stream of particles reflects light, although faintly and rarely seen. Moonless nights of winter are the best time to see the zodiacal light. and nowhere better than here, on the Tropic of Cancer, where the plane of the solar...

 Skeletal Similarities in Mammals

What a piece of work is the mammalian skeleton. I don't mean it is beautiful in itself, although I think it is. I mean the fact that we can talk about 'the' mammalian skeleton at all: the fact that such a complicatedly interlocking thing is so gloriously different across the mammals, in all its parts, while simultaneously being so obviously the same thing throughout the mammals. Our own skeleton is familiar enough to need no picture, but look at this skeleton of a bat. Isn't it fascinating ho...