Question: when you conduct work does it harm the solar system?

Paul Roche answered on 16 Jun 2010:

The solar system is very big, very old, and will be around a lot longer than humans probably will, so it’s hard to imagine what we can do that will really harm it. We can certainly mess up the biosphere of Earth, and we’re doing a pretty good job of that already, but the “solid Earth” (the big ball of rock and iron that is the physical planet) is almost totally ignorant of our presence – even mountain-sized space rocks smashing into the planet at 20 times the speed of a bullet only leave craters 200km across – big fur humans, tiny for a planet…

As an astronomer, all I do is observe – astronomy is quite an odd science in that respect, as we don’t really do experiments – we look at things from a (vast) distance, and try to figure out (using our knowledge of physics and chemistry) what is happening out there. Occasionally, space scientists can do some “harmful” things like the Deep Impact mission in 2005, where NASA “shot” a comet to see what was under the surface – but even hitting a big ice ball with a 300kg lump of copper, making a hole the size of Wembley stadium, had a tiny affect on the comet…so not really harmed at all.