The volcano Maat Mons on Venus is shown in this computer generated three-dimensional perspective of the planet's surface, based on data from the Magellan mission. Credit: NASA/JPL/Caltech.
Using archival radar images taken in the 1990s by NASA’s Magellan spacecraft, scientists have found evidence of recent active volcanism on Venus. The images revealed a volcanic vent that changed shape and increased significantly in size over an eight-month period.
The scientists say their findings confirm long-held suspicions that the planet, which is known to have a very geologically young surface and evidence of past volcanic eruptions, is still active today.
“We made the discovery in the most likely place that there should have been new volcanism,” said Robert Herrick, a geophysicist at the University of Alaska Fairbanks, speaking at a briefing on March 15, 2023 from the Lunar and Planetary Science Conference in Texas. “Extrapolating from a data set of one for an entire planet could be dangerous, but most scientists would say it’s pretty good evidence that being able to catch an eruption in an eight-month time frame means that others are taking place as well. It confirms there is modern geological activity on Venus.”
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.
According to the most widely accepted theories, the Moon formed about 4.5 billion years ago after a Mars-sized object (Theia) collided with Earth. After the resulting debris accreted to create the Earth-Moon system, the Moon spent many eons cooling down. This meant that a few billion years ago, lakes of lava were flowing across the surface of the Moon, which eventually hardened to form the vast dark patches (lunar maria) that are still there today.
Thanks to the samples of lunar rock brought back to Earth by China’s Chang’e 5 mission, scientists are learning more about how the Moon formed and evolved. According to a recent study led by the Chinese Academy of Geological Sciences (CGAS), an international team examined these samples to investigate when volcanism on the Moon ended. Their results are not only filling in the gaps of the Moon’s geological history but also of other bodies in the Solar System.
Ever since the announcement last September that astronomers found evidence of phosphine in the clouds of Venus, the planet has been getting a lot of attention. It’s not surprising. Phosphine is a potential biosignature: On Earth, it is produced by microbial life. Might a similar biological process be taking place in the skies of our sister planet? It’s a tantalizing prospect, and is definitely worth examining closely, but it’s too early to be sure. Microbes aren’t the only way to get phosphine. A new paper published on July 12th in the Proceedings of the National Academy of Science suggests that volcanism might instead be to blame for the strange chemistry in the Venusian cloud tops.
Artist's concept of a Europa Clipper mission. Credit: NASA/JPL
In about three years, NASA plans to launch a robotic orbiter that will study Jupiter’s mysterious moon Europa. It’s called the Europa Clipper mission, which will spend four years orbiting Europa to learn more about its ice sheet, interior structure, chemical composition, and plume activity. In the process, NASA hopes to find evidence that will help resolve the ongoing debate as to whether or not Europa harbors life in its interior.
Naturally, scientists are especially curious about what the Clipper mission might find, especially in Europa’s interior. According to new research and modeling supported by NASA, it’s possible that volcanic activity occurred on the seafloor in the recent past – which could be happening still. This research is the most detailed and thorough 3D modeling on how internal heat is produced and transferred and what effect this will have on a moon.
The largest and most well known irregular mare patch, Ina. Image credit: NASA/GSFC/Arizona State University
Regions of the Moon known as irregular mare patches – formed by magma cooling from a volcanic eruption – have almost no big craters, indicating that they must be relatively young. By studying the distribution of craters within them, we can estimate when these regions were formed: no more than 100 million years ago.
Venus may not have had Earth-like tectonic plates or volcanism for the last billion years, according to a new study. A deep look at a giant impact crater on Venus suggests the planet hasn’t experienced any tectonic activity in the recent past, and might be covered with a in a single outer plate. If so, this would essentially rule out any recent volcanic activity on the planet that many consider Earth’s twin.
The first lava tube skylight discovered on the moon. Image credit: JAXA/SELENE
Could lava tubes on the Moon and Mars play a role in establishing a human presence on those worlds? Possibly, according to a team of researchers. Their new study shows that lunar and Martian lava tubes might be enormous, and easily large enough to accommodate a base.
This figure shows the volcanic peak Idunn Mons (at 46 degrees south latitude, 214.5 degrees east longitude) in the Imdr Regio area of Venus. The colored overlay shows the heat patterns derived from surface brightness data collected by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), aboard the European Space Agency's Venus Express spacecraft. Image credit: NASA
Despite the similarities our world has with Venus, there is still much don’t know about Earth’s “Sister planet” and how it came to be. Thanks to its super-dense and hazy atmosphere, there are still unresolved questions about the planet’s geological history. For example, despite the fact that Venus’ surface is dominated by volcanic features, scientists have remained uncertain whether or not the planet is still volcanically active today.
While the planet is known to have been volcanically active as recent as 2.5 million years ago, no concrete evidence has been found that there are still volcanic eruptions on Venus’ surface. However, new research led by the USRA’s Lunar and Planetary Institute (LPI) has shown that Venus may still have active volcanoes, making it the only other planet in the Solar System (other than Earth) that is still volcanically active today.
Volcanoes are an impressive force of nature. Physically, they dominate the landscape, and have an active role in shaping our planet’s geography. When they are actively erupting, they are an extremely dangerous and destructive force. But when they are passive, the soil they enrich can become very fertile, leading to settlements and cities being built nearby.
Such is the nature of volcanoes, and is the reason why we distinguish between those that are “active” and those that are “dormant”. But what exactly is the differences between the two, and how do geologists tell? This is actually a complicated question, because there’s no way to know for sure if a volcano is all done erupting, or if it’s going to become active again.
Put simply, the most popular way for classifying volcanoes comes down to the frequency of their eruption. Those that erupt regularly are called active, while those that have erupted in historical times but are now quiet are called dormant (or inactive). But in the end, knowing the difference all comes down to timing!
Sarychev volcano, (located in Russia’s Kuril Islands, northeast of Japan) in an early stage of eruption on June 12, 2009. Credit: NASA
Active Volcano:
Currently, there is no consensus among volcanologists about what constitutes “active”. Volcanoes – like all geological features – can have very long lifespans, varying between months to even millions of years. In the past few thousand years, many of Earth’s volcanoes have erupted many times over, but currently show no signs of impending eruption.
As such, the term “active” can mean only active in terms of human lifespans, which are entirely different from the lifespans of volcanoes. Hence why scientists often consider a volcano to be active only if it is showing signs of unrest (i.e. unusual earthquake activity or significant new gas emissions) that mean it is about to erupt.
Aleutian island #volcano letting off a little steam after the new year on Jan 2, 2016. #YearInSpace. Credit: NASA/Scott Kelly/@StationCDRKelly
By this definition, those volcanoes that have erupted in the course of human history (which includes more than 500 volcanoes) are defined as active. However, this too is problematic, since this varies from region to region – with some areas cataloging volcanoes for thousands of years, while others only have records for the past few centuries.
As such, an “active volcano” can be best described as one that’s currently in a state of regular eruptions. Maybe it’s going off right now, or had an event in the last few decades, or geologists expect it to erupt again very soon. In short, if its spewing fire or likely to again in the near future, then it’s active!
Dormant Volcano:
Meanwhile, a dormant volcano is used to refer to those that are capable of erupting, and will probably erupt again in the future, but hasn’t had an eruption for a very long time. Here too, definitions become complicated since it is difficult to distinguish between a volcano that is simply not active at present, and one that will remain inactive.
Volcanoes are often considered to be extinct if there are no written records of its activity. Nevertheless, volcanoes may remain dormant for a long period of time. For instance, the volcanoes of Yellowstone, Toba, and Vesuvius were all thought to be extinct before their historic and devastating eruptions.
The area around Mount Vesuvius, which erupted in 79 CE, is now densely populated. Credit: Wikipedia Commons/Jeffmatt
The same is true of the Fourpeaked Mountain eruption in Alaska in 2006. Prior to this, the volcano was thought to be extinct since it had not erupted for over 10,000 years. Compare that to Mount Grímsvötn in south-east Iceland, which erupted three times in the past 12 years (in 2011, 2008 and 2004, respectively).
And so a dormant volcano is actually part of the active volcano classification, it’s just that it’s not currently erupting.
Extinct Volcano:
Geologists also employ the category of extinct volcano to refer to volcanoes that have become cut off from their magma supply. There are many examples of extinct volcanoes around the world, many of which are found in the Hawaiian-Emperor Seamount Chain in the Pacific Ocean, or stand individually in some areas.
For example, the Shiprock volcano, which stands in Navajo Nation territory in New Mexico, is an example of a solitary extinct volcano. Edinburgh Castle, located just outside the capitol of Edinburgh, Scotland, is famously located atop an extinct volcano.
Aerial photograph of the Shiprock extinct volcano. Credit: Wikipedia Commons
But of course, determining if a volcano is truly extinct is often difficult, since some volcanoes can have eruptive lifespans that measure into the millions of years. As such, some volcanologists refer to extinct volcanoes as inactive, and some volcanoes once thought to be extinct are now referred to as dormant.
In short, knowing if a volcano is active, dormant, or extinct is complicated and all comes down to timing. And when it comes to geological features, timing is quite difficult for us mere mortals. Individuals and generations have limited life spans, nations rise and fall, and even entire civilization sometimes bite the dust.
But volcanic formations? They can endure for millions of years! Knowing if there still life in them requires hard work, good record-keeping, and (above all) immense patience.
