This week’s new questions

Is shortsightedness found in other animals? And how big would an asteroid hitting Mars or the moon have to be to cause trouble on Earth?

30 July 2025

2C0KN5C Funny husky dog in glasses lying on the grass in a summer park — Roman Lacheev/Alamy

Last Word is �鶹��ý’s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email lastword@newscientist.com

Is short-sightedness found in other animals? Did it affect ancient humans too?

Simon Pearce

Bromley Cross, Lancashire, UK

Asteroi?d impact. The doomsday and extinction scene. Meteor hits the planet at high speed. ; Shutterstock ID 2645714679; purchase_order: -; job: -; client: -; other: - — Gergitek/Shutterstock

Could a massive asteroid that hit Mars or the moon affect Earth? How big would it need to be, and what would happen?

John Rymell

London, UK

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.

�鶹��ý 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.

Terms and conditions apply.