Magellan – Venus has long been assumed to be Earth’s twin, and a NASA mission to examine the planet was launched in the 1990s.
Scientists examined historical pictures of Venus’s surface and identified indications of volcanic activity on the planet.
A volcanic vent is shown in a new look at the orbiter’s view of a point near Venus’s equator.
During the period of eight months, it altered shape and size.
According to the researchers, the photographs of the vents are the first geological evidence of recent volcanic activity on Venus’s surface.
The findings were published in the journal Science on Wednesday.
The findings were also reported during the 54th Lunar and Planetary Science Conference, which was held in Texas.
The Magellan mission was one of the first to photograph the whole surface of Venus before falling into its perilous atmosphere in 1994 to acquire the last data.
But, during the next decade, a slew of new missions, including:
- The Venus Emissivity
- Radio Science
The volcanic landscape
The orbiter’s equipment will be used to figure out why Venus became blanketed in volcanic plains and topped by an unfriendly atmosphere.
According to Robert Herrick, the study’s lead author, a research professor at the University of Alaska Fairbanks, and a member of the VERITAS science team:
“NASA’s selection of the VERITAS mission inspired me to look for recent volcanic activity in Magellan data.”
“I didn’t really expect to be successful,” he continued.
“But after about 200 hours of manually comparing the image of different Magellan orbits, I saw two images of the same region taken eight months apart exhibiting telltale geological changes caused by an eruption.”
Herrick noticed the changes in photos of Atla Regio, a highland region containing Venus’ two most active volcanoes, Ozza Mons and Maat Mons.
The two are on par with the world’s largest volcanoes.
Herrick did remark, however, that the two Venusian volcanoes are more spread out because they have lower slopes.
Between February and October 1991, Herrick observed activity at a volcanic vent on the north side of a domed volcano linked to Maat Mons.
Magellan’s February vent image shows a circular vent less than a square mile (2.2 square kilometers) in size, with high inner walls and sloped lava spots.
Eight months later, Magellan imagined another image that showed a second vent that was malformed.
The lava lake on the rim roughly quadrupled in size.
While there are clear differences, it’s worth noting that the two photographs were captured from opposite perspectives.
Also, the photos were obtained at a lower resolution than most modern spacecraft cameras.
Venus 3D mapping
In an attempt to determine what was generating the changes, Robert Herrick collaborated with Scott Henley to construct computer models of the vent.
Hensley works at NASA’s Jet Propulsion Laboratory in Pasadena, California, as a VERITAS project scientist.
“Only a couple of the simulations matched the imagery, and the most likely scenario is that volcanic activity occurred on Venus’ surface during Magellan’s mission,” said Hensley.
“While this is just one data point for an entire planet, it confirms there is modern geological activity.”
According to experts, the lava flow caught by Magellan in 1991 was equivalent to the 2018 Kilauea eruption in Hawaii.
“This was a needle-in-a-haystack search with no guarantee that the needle exists,” said Herrick.
“Finding a change that could be clearly confirmed as real was absolutely a surprise.”
“We were pretty certain that Venus is volcanically active, but we don’t know if eruptions occur every few months, years, once every 10,000 years, or longer,” he continued.
“All options could have fit with existing data.”
“Unless we got incredibly lucky, we now know the frequency is every few months or so, similar to the family of Earth’s big basaltic intraplate volcanoes like Hawaii, the Galapagos Islands, Canary Islands, etc.”
Although a tremor may have caused the walls of the volcanic vent to collapse, experts believe the activity would have resulted in a volcanic eruption.
Volcanoes act as windows into the interiors of planets, allowing scientists to learn more about the factors that determine a planet’s habitability.
VERITAS missions, like Magellan’s, will aid scientists in their understanding of Venus.
The future mission will employ radar to produce global 3D maps of Venus, capturing data on its surface composition, gravitational field, and history.
Jennifer Whitten, the associate deputy lead investigator, applauded the results, saying:
“Venus is an enigmatic world, and Magellan teased so many possibilities.”
“Now that we’re very sure the planet experienced a volcanic eruption only 30 years ago, this is a small preview for the incredible discoveries VERITAS will make.”