NASA/JPL
Venus is about the same size, mass and density as Earth. As such, it must be generating heat internally (by decaying radioactive elements) at roughly the same rate as Earth. On Earth, one of the main ways this heat escapes is through volcanic eruptions. At least 50 volcanoes erupt during an average year.
But despite decades of observations, no clear signs of volcanic eruptions on Venus have been seen until now. A new study by geophysicist Robert Herrick of the University of Alaska Fairbanks, which he reported at the Lunar and Planetary Science Conference in Houston this week and published in the journal Science, finally reveals one of the planet’s volcanoes. I caught
Studying the surface of Venus is not easy. This is because Venus has a dense atmosphere containing continuous cloud layers at altitudes between 45 and 65 km that are opaque to most wavelengths of radiation, including visible light. The only way to get a detailed view of the ground from above the clouds is with a downward-looking radar from an orbiting spacecraft.
ISAS/JAXA
Create an image of the surface using a technique known as aperture synthesis. This allows for different intensities of radar echoes bouncing off the ground, including time delays between transmission and reception, and slight shifts in frequency corresponding to whether the spacecraft is closer or further away from the source of a particular echo. It’s a combination. The resulting image looks more like a black-and-white photograph, except that the lighter areas usually correspond to rougher surfaces and the darker areas correspond to smoother surfaces.
NASA/JPL
NASA’s Magellan spacecraft orbited Venus from August 1990 to October 1994, using this type of radar technology to map the surface of Venus with a spatial resolution of up to about 100 meters. More than 80% of the surface has been shown to be covered by lava flows, but how recently the youngest lava flows erupted and whether eruptions continue today will remain a mystery for the next 30 years. bottom.
