Venus, often called Earth's twin, hides a fiery secret beneath its thick clouds: volcanoes. For decades, scientists have debated whether Venus is still volcanically active. Now, an unexpected ally—Hawaii’s massive 2022 Mauna Loa eruption—is providing new clues. By studying Earth’s largest active volcano, researchers are unlocking methods to detect eruptions on Venus. Here are ten key insights that connect these two worlds.

1. The Evidence for Active Volcanoes on Venus

Spacecraft like NASA’s Magellan mapped Venus’s surface in the 1990s, revealing thousands of volcanoes. But static images can’t tell if they are active. Recent radar data from the European Space Agency’s Venus Express mission showed changes in surface brightness around volcanic vents, suggesting fresh lava flows. Additionally, spikes in sulfur dioxide in Venus’s atmosphere hint at ongoing volcanic emissions. These indirect signs strongly imply that Venus is not a dead world—it’s still geologically alive.

2. Why the Mauna Loa 2022 Eruption Is a Game-Changer

Earth’s largest volcano, Mauna Loa, erupted for the first time in 38 years in November 2022, spewing lava and gas. Scientists extensively monitored this eruption using satellites, ground sensors, and aircraft. The data collected—thermal signatures, gas composition, and ground deformation—offers a perfect Earth-based analog for how Venusian eruptions might look. By understanding what Mauna Loa’s eruption “looks like” from orbit, scientists can better interpret Venusian data.

3. Comparing Hot Spot Volcanoes on Both Planets

Mauna Loa is a hot spot volcano, formed by a plume of molten rock rising from deep within the mantle. Venus has similar features, such as the vast volcanic plains and large shield volcanoes like Sapas Mons and Maat Mons. Some models suggest that Venus lacks plate tectonics, so hot spot volcanism might be the dominant eruption style. Comparing the thermal evolution of a Hawaiian hot spot eruption with Venusian analogs helps refine detection methods.

4. Radar’s Role in Spotting Fresh Lava

Magellan used radar to pierce Venus’s clouds and map its surface. One key sign of active volcanism is a change in radar backscatter—the signal strength bounces differently off fresh, rough lava versus weathered rock. During the Mauna Loa eruption, scientists used synthetic aperture radar (SAR) to track lava flows in real time. This direct calibration between ground-truth and radar imagery on Earth offers a template for interpreting future radar missions to Venus.

5. Thermal Emissions: What Heat Tells Us

Cooling lava emits heat, detectable by thermal infrared sensors. On Venus, the atmosphere is so hot and thick that surface heat signatures are hard to isolate. However, the 2022 eruption taught researchers how to subtract atmospheric interference. By measuring the cooling curve of Mauna Loa’s flows, scientists developed algorithms that can filter out noise and spot subtle thermal anomalies on Venus—a promising technique for NASA’s upcoming VERITAS mission.

6. Gas Chemistry: Sulfur Dioxide and Other Clues

Volcanic eruptions release massive amounts of gas, especially sulfur dioxide (SO₂). On Venus, SO₂ levels in the upper atmosphere fluctuate dramatically. The 2022 Mauna Loa eruption produced a clear SO₂ plume that was tracked by satellites like TROPOMI. Comparing the dispersion and chemical reactions of Earth’s volcanic plumes helps Venus scientists model how quickly SO₂ from a Venusian eruption would be destroyed or transported, offering a timeline for recent activity.

7. The Challenge of Venus’s Thick Atmosphere

Unlike Earth, Venus has a crushing atmosphere 92 times denser, made mostly of carbon dioxide. This makes orbital observations extremely difficult. The 2022 Hawaiian eruption provided a test bed for multi-wavelength remote sensing. Instruments that work well in Earth’s thin air (like shortwave infrared) may fail on Venus. By studying how different wavelengths penetrate Earth’s atmosphere during a volcanic blast, scientists can choose the best sensors for Venus orbiters.

8. Monitoring Ground Deformation from Space

Before an eruption, magma movement deforms the ground—upward swelling or sinking. On Earth, InSAR (Interferometric Synthetic Aperture Radar) measures millimeter-scale changes. The 2022 eruption saw measurable deformation around Mauna Loa’s summit. Applying InSAR to Venus is tricky due to its thick clouds and slow rotation, but new techniques refined using Hawaiian data now allow for long-baseline interferometry. This could reveal whether Venus’s volcanoes are inflating prior to eruption.

9. The Timeline of Venusian Volcanism

When did Venus last erupt? Some estimates suggest within the last few hundred years based on fresh-looking lava flows. Others argue for ongoing activity. The 2022 Hawaiian data helps constrain how quickly lava surfaces weather. Mauna Loa’s flows showed a rapid drop in radar roughness over just weeks. If Venusian flows weather similarly, then radar-bright features must be geologically young—possibly still cooling. This narrows down the window for active volcanism.

10. Future Missions: VERITAS, EnVision, and DAVINCI

NASA and ESA are planning new Venus missions launching in the next decade. VERITAS will map the surface in high-resolution radar; EnVision will study the atmosphere and surface interactions; DAVINCI will drop a probe through the atmosphere. Lessons from the 2022 Mauna Loa eruption are directly shaping their observation strategies. From radar calibration to gas detection, this Hawaiian eruption serves as a crucial Earth analog, bringing us closer to confirming—or debunking—the volcanic heartbeat of Venus.

In conclusion, the 2022 Kīlauea and Mauna Loa eruptions offered scientists a unique chance to practice detecting volcanic activity in an Earth-like setting. By applying these techniques to Venus, we may soon answer the age-old question: Is our sister planet still volcanically active? The evidence is piling up, and with upcoming missions, the truth may erupt any day.