January 13

Cassini made the first of this year’s 17 planned passes by Titan, the largest moon of Saturn. Using radar and other instruments, Cassini has penetrated the orange “smog” that tops Titan’s atmosphere to reveal lakes of liquid methane, channels carved by flowing methane, possible ice volcanoes, and many other exotic sights. Its continued reconnaissance will allow scientists to map all of Titan in greater detail, and to determine how the moon’s surface changes over time.

February 17

THEMIS in orbit

NASA launched a set of five small probes, known collectively as THEMIS (for the Greek goddess of justice and wisdom) to study the formation of aurorae -- the northern and southern lights -- by flying through Earth’s magnetic field. The colorful displays are triggered by interactions between the solar wind and Earth’s upper atmosphere.

February 25

Rosetta, a European spacecraft en route to a rendezvous with a comet, flew just 160 miles (250 km) above Mars to get a gravitational boost from the planet. Its instruments conducted several hours of observations.

February 28

Artist’s concept shows New Horizons skimming past Pluto, with Charon in the background. (NASA)

New Horizons got a gravitational “kick” that will cut several years off its flight time to the Kuiper Belt when it flew past Jupiter. The belt is a band of large iceballs beyond the realm of the planets. The craft’s parimary target is Pluto. The Jupiter encounter also gave New Horizons a chance to test its scientific instruments, and provided the first close-up look at Jupiter since the end of the Galileo mission in 2002.

July 7

After NASA cancelled then reinstated the mission last year, a spacecraft will set sail for the asteroid belt, where it will study some of the “leftovers” of the solar system’s formation. Dawn will orbit Vesta for about seven months beginning in late 2011, then head for the largest asteroid, Ceres, which it will begin orbiting in early 2015.

August 4

Artist's rendering of Mars probe Phoenix landing. (NASA)

The next Mars lander, Phoenix, took flight from Cape Canaveral. When it arrives in May 2008, it will land near the north polar ice cap, then probe the frigid landscape for evidence of the chemistry of life. It will drop samples of soil and ice into tiny ovens, which will reveal the chemical composition of the samples. Phoenix is the first mission in the Mars Scout program.

August 17

The Japanese Space Agency will launch Kaguya, a set of three satellites that will orbit the Moon. The satellites will map the composition of the lunar surface and the Moon's gravity field, study the interaction of the solar wind with the Moon and Earth, and test new technologies for future lunar missions.

September 26

After NASA cancelled then reinstated the mission last year, a spacecraft will set sail for the asteroid belt, where it will study some of the “leftovers” of the solar system’s formation. Dawn will orbit Vesta for about seven months beginning in late 2011, then head for the largest asteroid, Ceres, which it will begin orbiting in early 2015.

September or Later

The Japanese Space Agency will launch Kaguya, a set of three satellites to orbit the Moon. The satellites will map the composition of the lunar surface and the Moon’s gravity field, study the interaction of the solar wind with the Moon and Earth, and test new technologies for future lunar missions.

 

November

Rosetta will pick up more speed when it flies past Earth. The maneuver also will place it on target to rendezvous with an asteroid next year. It will arrive at Comet 67P/Churyumov-Gerasimenko in 2014, then spend several months flying in formation with the comet and dropping a small lander on its surface.

Ongoing at Mars

• Odyssey, an orbiter that has discovered evidence of extensive frozen water
• Express, a European orbiter that is probing for evidence of deeper water
• Spirit and Opportunity, twin rovers
• Reconnaissance Orbiter, which is mapping Mars in the greatest detail to date

Ongoing at Venus

• Express, a European orbiter that it studying the planet’s atmosphere

See also Explorations in 2006