Since it reached Venus in April 2006, Venus Express has logged many firsts at our solar system's second planet. One of the most significant findings was signs Venus has been volcanically active in the last three million years -- suggesting the planet may still be geologically active.
The MESSENGER mission has photographed Mercury and found evidence of volcanic activity shaping the planet's surface. Some of the lava flows are between one billion and two billion years old. Although that is still relatively old by terrestrial standards, it tells planetary scientists that volcanic activity continued well after Mercury formed about 4.5 billion years ago.
This mission has been orbiting Mars since 2001 and is still going strong. Its infrared spectrometer has found data of regional explosive andesitic volcanism on this planet dominated by gentler basaltic lava flows.
Lunar Reconnaissance Orbiter
The Lunar Reconnaissance Orbiter is taking high-resolution photographs of the lava flows, fissures and other volcanic features on the Moon, as well as studying the mineralogy and topography of the surface to learn more about the Moon's volcanic history.