BBC Science Focus - 10.2019

JULES HOWARD Zoologist, science writer

THIS ISSUE’S EXPERTS

DR CHRISTIAN JARRETT Neuroscientist, science writer

DR ALASTAIR GUNN Astronomer, astrophysicist

ALEX FRANKLIN- CHEUNG Environment/ climate expert

LUIS VILLAZON Science/tech writer

PROF ROBERT MATTHEWS Physicist, science writer

DR HELEN SCALES Oceans expert, science writer

ALOM SHAHA Science teacher, author

CHARLOTTE CORNEY Zoo director, conservationist

DR PETER J BENTLEY Computer scientist, author

DR HILARY GUITE Former GP, science writer

DR EMMA DAVIES Chemistry expert, science writer

Q

&

A

GETTY

IMAGES

ANNA BRIGGS, PLYMOUTH

HOW FAR FROM EARTH

COULD ALIENS DETECT OUR

RADIO SIGNALS?

While commercial radio broadcasts began around 100 years ago, these early transmissions used frequencies that were either mopped up by the atmosphere or drowned out by radio emission from the Sun. In contrast, military radar transmissions set up during the Cold War to detect incoming ballistic missiles have the power and frequency characteristics to be detected over hundreds of light-years – and have already broadcast our existence to any aliens within around 60 light-years of the Earth. RM

ALL YOUR

QUESTIONS

ANSWERED