Polar research scientist Ginny Catania responds to a Brazilian student’s question, and explains why what happens at the poles can have global impacts.

A student from Spain wonders if it’s true that elephants have good memories. Elephant ecologist Stephen Blake answers the question, and talks about what makes elephants so special.

A British student wonders how the energy issue will impact our planet. Yale professor and ‘energy futurist’ Arnulf Gruber responds, and talks about what kids can do to help.

In the past, desalination relied on boiling the water. But today’s newer techniques use a semi-permeable membrane.

A boy from Laos wonders how long we – or our descendants – might live. An MIT biologist responds, and talks about new research that could help extend our lifespan.

Even before birth – and throughout life – all animals yawn. But scientists are still unclear about why. Robert Provine, a neuroscientist at the University of Maryland in Baltimore, has studied yawning for over 30 years.

Nina Amatulli, in the second grade at The American School in Japan, asks the scientists. Hear the response from Robert Hazen of the Carnegie Institution For Science.

That depends a lot on the choices that we make, says a NASA scientist, in response to a question from a student in northern China.

Nuclear engineer Erich Schneider responds to a question asked by a student from Cote d’Ivoire about the purpose of nuclear power.