MANY scientists have long been puzzled if Venus, our closest neighboring planet, has been geologically active. Planetary scientists have long been researching and using data from the Magellan spacecraft, the Venus radar mapper, to simulate and create models to create theories and, hopefully, confirm that Venus is one of the few places in the solar system, the other one to be the moon of Jupiter, Io, to have experienced volcanism.
Filipino scientist Dr. Gerald Galgana, a Balik Scientist and a postdoctoral research fellow at the Lunar and Planetary Institute at the National Aeronautics and Space Administration (Nasa) in Houston, Texas, in the United States, has long been doing research on Venus and its volcanoes.
“I have been doing research on Venus using data from the Magellan spacecraft in the 1990s,” Galgana said in an interview with the BusinessMirror. He might be the only Filipino doing research on crustal and volcano deformation using numerical models on Venus.
Venus, Earth’s evil twin
Venus is the hottest planet in the solar system, even if it is the second planet closest to the sun. Compared to Mercury and even Earth, Venus has a very dense atmosphere. Ninety-six percent is made up of carbon dioxide and the rest is a mixture of nitrogen and sulphuric acid, therefore, attributing to the runaway greenhouse effect.
“The atmosphere in Venus is really thick,” Galgana said. It is very dense and heavy. The surface temperature is at 460 degrees Celsius which could vary to 470° C. “It could actually melt lead,” Galgana added.
An inhospitable planet, with the high temperature and almost the same size and similar mass as that of the Earth, it has been hailed as our planet’s “evil twin.”
A consensus among planetary scientists point out that Venus is a one-plate planet. Compared to Earth, Venus has no plate tectonics. Plate tectonics is a theory by scientists where several plates compose the lithosphere, Earth’s outer shell and glide over the mantle. The movements of these plates cause earthquakes on Earth. But for Venus being a one-plate planet, its earthquake is produced through volcanic eruptions. Scientists of today believe that the volcanoes in Venus have covered the planet in a cataclysmic amount of lava some 500 million years ago.
Galgana said, “There was a massive surfacing that happened and many scientists think that the surface of Venus is actually very young compared to other planets.”
In the talk he gave at the National Institute of Geological Sciences (NIGS) Lecture Series at University of the Philippines Diliman, Galgana highlighted that Venus is a very important place to study volcanoes.
“Venus is actually a laboratory to look at volcanism at a very large scale,” he said.
Venus volcanology
Through the data and pictures obtained from the Magellan spacecraft, scientists were given an eye to the Venusian surface.
“With the near global map of Venus, we are able to see various landforms. They were able to see the surface,” Galgana said. He added, “There are a lot of volcanoes distributed along the surface of Venus.”
To date, no one has counted them yet, but the total number might be even over 1,000,000.
Venus has shield volcanoes, both large and small. Shield volcanoes are made up of entirely fluid magma flows which resemble a warrior’s shield. There are also volcanoes on Venus called “pancake domes.” From the word itself, it looks like a pancake on a bird’s eyeview and are widely scattered on Venus. Another feature of the Venusian surface is the presence of radial dikes or novae when it forms a network. There are overlapping radial dike systems on Venus, according to Galgana.
They are influenced by the magmatic pressure, modified by topography, gravitational stresses and regional tectonic stresses.
“There are about 163 giant radial giant swarms that are found in Venus. Their radius is about 42,000 kilometers,” Galgana said. Most of these dikes have settled uplifts or are flat and some are depressed in the middle.
Galgana also added that there are two main causes of radial dike formation: the tensile stresses and mantle upwelling which meant the rising of the mantle of Venus. Also, there are hot spots where these are fixed locations, an intrinsic property inside Venus that just readily flows out magma continuously.
The magma that is erupted on Venus is mostly basaltic. Galgana explained that the materials that come out of the Venusian volcanoes have low silica content. “It flows readily because of less viscosity and not explosive. In short, does not have pyroclastic flows.”
Researchers, through the European Space Agency’s Venus Express spacecraft, found out that Venus was not just geologically active but might be actively resurfacing through the solidified lava flows spewed by its volcanoes projected to be about 250,000 years or less.
Through geological terms, it is active at present, according to a paper by Suzanne Smrekar and her colleagues published in the scientific journal Science.
Earth’s volcanoes vs Venus’s volcanoes
There are many types of volcanoes on Earth. According the Dr. Mario Aurelio, a geologist and the director of NIGS, in many parts of the Earth where there are a number of active volcanoes, like Indonesia, New Zealand, Alaska and Japan, “the magma that comes out in volcanoes is mainly due to subducting plates that goes in another plate and creates partial melting due to high-pressure temperature conditions. Magma is then formed because of melting. It is different from the source of magma in Venus.”
However, Earth has also volcanoes that produce magma by hot spots, such as the same one in Venus. “We have the ones in Hawaii where until now just steadily flows out hot magma”.
“The Galapagos and Iceland volcanoes are a different story, too,” Aurelio added. “The Galapagos volcanoes are along the East Pacific rise-rift area where the plates are moving away from each other, hence, magma flows out.”
With all these volcanoes, Aurelio pointed out that we cannot really compare the processes in Earth and Venus. This is because of the limited data that we have on Venus compared to that on Earth.
“Perhaps now, I think it is not that appropriate to compare Earth and Venus because the number of data we have on Earth is more significant than we have on Venus.” Mostly, all we have on Venus are numerical models and are yet to be verified soon.
Aurelio also mentioned that according to Galgana, there are still debates on Venus’s plate. There are two schools of thought. “There are people who believe that Venus has plate tectonics and those who believe that Venus is a one-plate planet.”
Future Venus exploration and foresight
The current research has mainly focused on the universe beyond our solar system. Stephen Hawking and Russian billionaire Yuri Milner announced on April 12 that a mission to the nearest star, Alpha Centauri, is already in the pipeline with the initial funding of $1.10 billion.
A long starshot mission is on the way, but perhaps, for planetary scientists like Galgana, he only hopes of Nasa and other stakeholders to fund another spacecraft to Venus.
“I want a new spacecraft to orbit Venus and obtain more data, to see if what we think is right or maybe we can modify it,” Galgana said. He added that the more data you have, the more improvement the models will have. When asked why it is important to understand Venus, he highlighted that it is the only planet that has volcanoes in the solar system and the nearest laboratory we have for volcanoes. He also told the BusinessMirror that Venus is important for studies in climate change.
“We have to study Venus and what caused the runaway greenhouse gases in it,” he said. “The greenhouse effect they have could happen to us because of the extreme carbon-dioxide concentration that we are producing and how it will affect Earth in the next years to come.”
For the organizer of the NIGS lecture series, Dr. Allan Fernando said lectures like these are important and needs to be discussed by students and even the public. “The lecture is rarely discussed in the Philippines. His [Galgana’s] topic in modeling and volcanoes can be of use to many researchers and students, especially on the volcano hazards in the Philippines and even in other places.”
“To be able to listen to Galgana and his research is a rare opportunity,” Aurelio also added. He also cited that it opens doors to many questions about the Earth and its neighbors. He asked, “Can we see the processes in Venus soon? Are they the same with Earth?”
These are questions that will be answered in due time.
Image credits: Stephanie Tumampos
