Size does matter: Putting space into perspective

[n2doc]

Marcus Chown, consultant


Big things - like dinosaurs and the universe - capture young imaginations. But then comes the inevitable next question: how big? You can imagine a diplodocus being as long as, say, three London buses. But, when it comes to the universe, Adams's point hits home. Just how big is the sun? Or the Orion Nebula? Or the Virgo Galaxy cluster?

Gott, like me, has spent a lifetime trying to get his head around such mind-dwarfing questions. The difference is that he has done something concrete about it. He has collaborated on a book with astrophotographer Robert Vanderbei. And it is an absolute delight.

Sizing up the Universe is a truly special book that will give you a feel for just how big the things out in space really are. On one page we find a picture of the United States juxtaposed with, and completely dwarfed by, a sunspot. On another, the Grand Canyon is superimposed on Mars's Valle Marineris. Our canyon is smaller than even the tributaries of the great Martian canyon, a great crack in the surface snaking a third of the way around the Red Planet.



The image that I found most arresting, though, is of Itokawa, a small near-Earth asteroid on which the Japanese Hyabusa space probe landed in 2005. It is one of the weirdest celestial bodies ever imaged, more a loose aggregation of rubble than a solid body. In the same shot, Gott and Vanderbei have put for comparison the International Space Station, the Hubble Space Telescope, the Space Shuttle and even the tiny figure of space-walking astronaut Bruce McCandless. Not only does this give you a sense of just how small Itokawa is, but an immense appreciation of the achievement of the Japanese in landing on the asteroid. Respect.

http://www.newscientist.com/blogs/culturelab/2010/12/size-does-matter-putting-space-into-perspective.html