Secret: I wasn't a good student. I changed that. Excited to join #citizenscience for #endurance microscholarships! pic.twitter.com/Ao3nITtzlu — Scott Kelly (@StationCDRKelly) September 30, 2016

BERKELEY, Calif. (KGO) -- A group of students in Berkeley got a firsthand account of what it's like to explore and live in outer space.With his feet firmly planted on the ground, retired astronaut Scott Kelly arrived to share his experiences with the students at Berkeley's School of the Madeleine. Many of them wondering, what was the best part?The 52-year-old Kelly and his brother Mark were both astronauts. In fact, NASA studied the twins to determine the effects of prolonged space travel on the human body.In February, Kelly returned from the International Space Station where he spent 340 consecutive days."Was it scary to come back from space?" asked one student."It can be scary, but like I said, it's also a lot of fun," Kelly said.Kelly is helping to promote apps, like one called Lab4Physics and Citizen Science that allow students to conduct experiments on their smart phone and other devices."STEM education and the Citizen Science initiative is very important to getting kids to study science because it is so important to our economy and our future," Kelly said.It's a message students say they heard loud and clear."If we don't study it, then our whole society, I personally believe, will fall apart," said Lila Higley of the School of the Madeleine."Does it make you want to study science and technology and maybe be an astronaut?""Yeah, having no gravity sounds pretty awesome."