From the February 2010 issue

New Horizons at Jupiter

NASA's New Horizons spacecraft began its journey to Pluto January 19, 2006. The most vital part of the mission since then occurred in February 2007, when it flew past Jupiter.
By | Published: February 22, 2010 | Last updated on May 18, 2023
In this artist’s rendering, New Horizons soars past Jupiter as the volcanic moon Io passes between the spacecraft and planet.

When NASA and the New Horizons team planned this mission to Pluto, speed was a paramount concern. Pluto made its closest approach to the Sun in 1989. Ever since, the icy dwarf planet has been heading into the solar system’s outer reaches, growing colder with each passing year. If New Horizons didn’t reach Pluto quickly, the planet’s tenuous atmosphere might completely freeze onto the surface. And scientists wouldn’t get another chance to observe the atmosphere until Pluto warmed up again in the 23rd century.