While the surface of Mars looks relatively unchanging now, it wasn’t always so. The tallest mountain in the Solar System is Olympus Mons, a giant shield volcano on Mars that reaches 21.9 km (13.6 miles) high, 2.5 times higher than Mount Everest here on Earth. Ancient lava flows surround the volcanic caldera, evidence of an active time.
New images from ESA’s Mars Express show how these lava flows created extremely sharp cliffs, as high as 7 km (4.3 miles) in some areas, which suddenly collapsed in mind-boggling landslides. One of these landslides occurred several 100 million years ago when a chunk of the volcano broke off and spread across the surrounding plains. If we could look back in time and see as it happened, it was certainly a very dramatic and turbulent epoch on Mars.
The enormous undersea volcano that erupted in Tonga last year was record-breaking in many regards. It generated the highest-ever recorded volcanic plume, it triggered a sonic boom that circled the globe twice, and was the most powerful natural explosion in more than a century.
Now, scientists studying the eruption say the volcanic plume created record-breaking amounts of volcanic lightning, the most intense lightning rates ever documented in Earth’s atmosphere. While the ash obscured the view, satellites and ground-based radio antennas with specialized instrument could peer through the ash and see every stage of the unfolding eruption. Over 200,000 lightning flashes were detected in the volcanic plume, more than 2,600 flashes every minute.
A new map created with decades-old radar imagery from NASA’s 1990’s Magellan mission shows the locations of a whopping 85,000 volcanoes on Venus. The detailed map displays where the volcanoes are, how they’re clustered, and how their distributions compare with other geophysical properties of the planet such as crustal thickness.
This comprehensive study of Venus will help planetary scientists answer many outstanding questions about the planet’s geological history, such as why doesn’t it have plate tectonics like Earth? Was it ever habitable, and if so, for how long?
Interest in the exploration of Venus has kicked up a notch lately, especially after a contested recent discovery of phosphine, a potential biosignature, in the planet’s atmosphere. Plenty of missions to Venus have been proposed, and NASA and ESA have recently funded several. However, they are mainly orbiters, trying to peer into the planet’s interior from above. But they are challenged by having to see through dozens of kilometers of an atmosphere made up of sulfuric acid.
That same atmosphere is challenging for ground missions. While some of the recently funded missions include a component on the ground, they are missing an opportunity that isn’t afforded on many other planets in the solar system – riding along in the atmosphere. Technologists have proposed everything from simple balloons to entire floating cities – we even heard of a plan to enclose the entirety of Venus in a shell and live on the surface of that shell. But for now, balloons seem to be a more straightforward answer. That is the mission modality proposed by a team of researchers at NASA’s Jet Propulsion Laboratory to discover more about something that was only confirmed to exist on Venus in the last week – volcanism.
Everyone loves looking at the Moon, especially through a telescope. To see those dark and light patches scattered across its surface brings about a sense of awe and wonder to anyone who looks up at the night sky. While our Moon might be geologically dead today, it was much more active billions of years ago when it first formed as hot lava blanketed hundreds of thousands of square kilometers of the Moon’s surface in hot lava. These lava flows are responsible for the dark patches we see when we look at the Moon, which are called mare, translated as “seas”, and are remnants of a far more active past.
In a recent study published in The Planetary Science Journal, research from University of Colorado Boulder (CU Boulder) suggests that volcanoes active billions of years ago may have left another lasting impact on the lunar surface: sheets of ice that dot the Moon’s poles and, in some places, could measure dozens or even hundreds of meters (or feet) thick.
Earth is a geologically active planet, which means it has plate tectonics and volcanic eruptions that have not ceased. This activity extends all the way to the core, where action between a liquid outer core and a solid inner core generates a planetary magnetic field. In comparison, Mars is an almost perfect example of a “stagnant lid” planet, where geological activity billions of years ago and the surface has remained stagnant ever since.
But as indicated by the many mountains on Mars, which includes the tallest in the Solar System (Olympus Mons), the planet was once a hotbed of volcanic activity. And according to a recent NASA-supported study, there is evidence that thousands of “super-eruptions” happened in the Arabia Terra region in northern Mars 4 billion years ago. These eruptions occurred over the course of 500-million years and had a drastic effect on the Martian climate.
Predicting volcanic eruptions is notoriously tricky. In large part this is because volcanos are unique, each with their own quirks and personalities: the lessons learned from studying one volcano may not apply directly to another. Luckily, researchers are getting better at finding warning signs that they can apply broadly. Some of the most well-known are heightened seismic activity, rising temperatures, expanding magma pools, and the release of gases. New research using satellite imagery now offers a new warning sign for underwater volcanos: a change in the color of the ocean.
The ultra-powerful James Webb Space Telescope will launch soon. Once it’s deployed, and in position at the Earth-Sun Lagrange Point 2, it’ll begin work. One of its jobs is to examine the atmospheres of exoplanets and look for biosignatures. It should be simple, right? Just scan the atmosphere until you find oxygen, then close your laptop and head to the pub: Fanfare, confetti, Nobel prize.
Of course, Universe Today readers know it’s more complicated than that. Much more complicated.
In fact, the presence of oxygen is not necessarily reliable. It’s methane that can send a stronger signal indicating the presence of life.
At a fundamental level, Mars is a volcanic planet. Its surface is home to the Solar System’s largest extinct volcano, Olympus Mons, and another trio of well-known volcanoes at Tharsis Montes. And those are just the highlights: there are many other volcanoes on the surface. Though that volcanic activity ceased long ago, the planet’s surface tells the tale of a world disrupted and shaped by powerful volcanic eruptions.