Current Event: “Recent” Volcanic Activity Found on the Moon

According to data collected by NASA, volcanoes were still erupting on the moon as recently as the Age of Dinosaurs on Earth. The finding overturns the long-held belief that the moon’s volcanic activity ended abruptly about one billion years ago. Instead, small amounts of lava continued to erupt from volcanic vents until less than 100 million years ago. That’s relatively recent in the 4.6-billion-year history of the moon. In 1971, astronauts on Apollo 15 saw an unusual feature that scientists later decided was an irregularly shaped collapsed volcano. It was originally thought to be a one-of-a-kind feature, but recently scientists have discovered about 70 similar features. These features, called irregular mare patches, suggest that the interior of the moon is warmer than scientists had thought. In particular, one astronomer said, “the lunar mantle had to remain hot enough to provide magma for the small-scale eruptions that created these unusual young features.” In addition, the moon’s volcanic activity apparently last much longer than previously believed.

A feature called Maskelyne is one of many newly discovered young volcanic deposits on the Moon. Called irregular mare patches (IMP’s), these areas are thought to be remnants of small basaltic eruptions that occurred much later than the commonly accepted end of lunar volcanism, 1 billion to 1.5 billion years ago. (© NASA/GSFC/Arizona State University)

Objective:

The moon is Earth’s only natural satellite and the only astronomical body other than Earth ever visited by human beings. The surface of the moon is covered with bowl-shaped holes called craters, shallow depressions called basins, and broad, flat plains known as maria. The vast majority of the moon’s craters were formed by the impact of meteoroids, asteroids, and comets. Basins are craters that are 190 miles (300 kilometers) or more across. Maria, the dark areas on the moon, make up about 16 percent of the surface area. Named for their resemblance to bodies of water (the word maria is Latin for seas), maria are cratered landscapes that were partly flooded by lava when volcanoes erupted. The lava then froze, forming rock. Since that time, meteoroid impacts have created craters in the maria. Scientists think that the maria formed between about 3 1/2 billion and 1 billion years ago. The Behind the Headlines news story and related World Book articles explore the moon and other astronomical topics.

Words to know:

• Apollo
• Astronaut
• Astronomy
• Lava
• Moon
• National Aeronautic and Space Administration (NASA)
• Satellite
• Solar system
• Space exploration
• Volcano

Discussion Topics:

1. Excluding Earth, five planets in the solar system have satellites. Ask your students to name the other five planets with satellites. (Students should say Mars, Jupiter, Saturn, Uranus, and Neptune. Dwarf planet Pluto also has satellites.)

2. Ask your students to debate, “One day, people will live on the moon.”

3. Ask your students to use World Book’s Timelines feature to view or add to the Milestones of Moon Study timeline. (Students may wish to use the “History of moon study” section of World Book’s Moon article for help.)