Context
- Recently, researchers detected evidence of volcanic eruption on Venus’ surface using data from NASA’s Magellan mission provided by NASA’s Jet Propulsion Laboratory.
| Planet Venus
– Earth’s Twin: Venus is Earth’s closest planetary neighbour which is similar in structure but slightly smaller than Earth. a. It is the second planet from the sun. – Thick & Toxic Atmosphere: Venus has an atmosphere 50 times denser than Earth. a. It is wrapped in a thick, toxic atmosphere filled with carbon dioxide that traps heat. – Inhabitable: Venus is the hottest planet in the solar system. The temperature of Venus is too high (about 471°C), and its atmosphere is highly acidic. – Other Features: It has no moons and no rings. a. Venus’ solid surface is a volcanic landscape covered with extensive plains featuring high volcanic mountains and vast ridges. b. b. It spins from east to west, the opposite direction from all other planets in our solar system but the same as Uranus. |
Volcanism on Venus
- The Magellan Mission of NASA, launched in 1989, provided crucial insights into Venus’ geology. The spacecraft used Synthetic Aperture Radar to map 98% of Venus’ surface between 1990 and 1992 revealed features that hinted at a tumultuous volcanic past.
Specific Sites
- Sif Mons: A volcano approximately 200 miles (300 km) wide located in the Eistla Regio region. It exhibited signs of eruption during the early 1990s.
- Radar images show a lava flow covering about 12 square miles (30 square km) of rock.
- It changed the perception that Venus is a dormant world.
- Niobe Planitia: A large volcanic plain where approximately 17 square miles (45 square kilometers) of rock were produced by lava flow.
Venusian Volcanic Activity
- A 2023 study revealed that a volcanic vent on Maat Mons in a region called Atla Regio expanded and changed shape during the Magellan mission.
- Maat Mons: In 2023, Magellan’s Radar images captured changes near the volcano Maat Mons.
- These changes indicated a recent eruption, providing direct geological evidence of volcanic activity on Venus.
- The outflow of molten rock filled the vent’s crater and spilled down its slopes.
Implications
- Venus’ Evolution: The discovery of recent volcanism suggests that Venus may be more volcanically active than previously thought.
- Understanding its volcanic history helps explain why Venus took a different evolutionary path than Earth.
- Climate Alterations: Massive volcanic outpourings in Venus’ ancient past likely altered its climate.
- Venus boasts scorching surface temperatures and a thick atmosphere that may have originated from intense volcanic activity.
| Volcanoes
– It is a vent or fissure in Earth’s crust through which lava, ash, rocks, and gases erupt. It can be active, dormant, or extinct. – An eruption takes place when magma (a thick flowing substance), formed when the earth’s mantle melts, rises to the surface. – The magma is lighter than solid rock, it can rise through vents and fissures on the surface of the earth. a. After it has erupted, it is called lava. – – Not all volcanic eruptions are explosive since explosivity depends on the composition of the magma. |
| Types and Characteristics
– Cinder Cones: These are small, steep-sided volcanoes formed by the accumulation of volcanic fragments around a single vent. a. Eruption Style: They erupt mostly small pieces of scoria and pyroclastics. b. Example: Capulin Volcano in New Mexico. – Composite Volcanoes (Stratovolcanoes): These are tall and steep with layers of lava, ash, and rock debris. They often have a conical shape. a. Eruption Style: High-viscosity lava, ash, and rock debris. b. Examples: Mount Rainier in Washington, and Mount Fuji in Japan. – Shield Volcanoes: These have gentle slopes and are shaped like a bowl or shield. They result from basaltic lava flows. a. Eruption Style: Low-viscosity lava that can flow great distances from the vent. b. Examples: Mauna Loa in Hawai’i, Iceland’s volcanic chain. – Lava Domes: These form when thick, viscous lava accumulates near the volcanic vent. They have steep sides. a. Eruption Style: Slow eruptions of highly viscous lava. a. b. Example: Novarupta dome in Alaska |