Panoramic Images/Alamy
John Davies
Lancaster, UK
We would certainly know it was coming. As it approached the sun, it would collide with the contents of the solar wind. Those subatomic particles would annihilate with their antimatter counterparts in the comet, releasing pure energy. The result would be a comet that blazed across the sky, emitting electromagnetic radiation right across the spectrum.
To answer this question – or ask a new one – email lastword@newscientist.com.
Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.
Â鶹´«Ã½ retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.
