MOSCOW  Russia’s top space researchers will hold a closed-door meeting to plan a mission to deflect 99942 Apophis, an asteroid that will fly close to Earth two decades from now, said Anatoly N. Perminov, the head of Russia’s space agency, during an interview on Russian radio on Wednesday.

Mr. Perminov said Apophis, named for the Egyptian god of destruction, is about three times the size of the Tunguska meteorite, apparently the cause of a 1908 explosion in Siberia that knocked over an estimated 80 million trees. He said that according to his experts’ calculation, there was still time to design a spacecraft that could alter Apophis’s path before it made a dangerous swing toward Earth.

“I don’t remember exactly, but it seems to me it could hit the Earth by 2032,” he said, adding, “We’re talking about people’s lives here. It’s better to spend several million dollars and create this system, which would not allow a collision to happen, than wait for it to happen and kill hundreds of thousands of people.”

In fact, Apophis’s chances of hitting Earth have been downgraded since it was discovered in 2004, NASA said this year. Scientists originally thought the orbit of the 1,000-foot-long asteroid gave it a 2.7 percent chance of hitting Earth on its first approach in 2029, but after studying its path they said it would remain 18,300 miles above the planet’s surface.