Hot flow anomalies, common space weather phenomena, are bigger on Venus than the entire planet and occur multiple times a day.
Hot flow anomalies are giant explosions of large amounts of energy on the outskirts of Earth's magnetic bubble known as the magnetosphere. However, since Venus doesn't have a magnetic bubble, the repercussions of these space weather explosions are more drastic.
Researchers from NASA's Goddard Space Flight Center in Greenbelt found that these explosions on Venus can be as big as the entire planet and take place multiple times a day, according to a press statement.
"Not only are they gigantic," said Glyn Collinson, a space scientist at NASA's Goddard Space Flight Center in Greenbelt. "But as Venus doesn't have a magnetic field to protect itself, the hot flow anomalies happen right on top of the planet. They could swallow the planet whole."
The observation made was based on data from European Space Agency's Venus Express. The data also provides information on how large and how frequent this kind of space weather is on Venus.
Owing to the Earth's strong magnetosphere, hot flow anomalies don't make it into the planet's atmosphere. However, they release so much energy just outside that the solar wind is deflected and can be forced to move back toward the sun. The absence of a magnetosphere on Venus creates a completely different picture.
The only defence Venus has over these solar winds is the outer layer of its atmosphere known as ionosphere. The sensitive pressure balance that exists between this ionosphere and solar winds is easily disrupted by the energy released during hot flow anomaly explosions.
This leads to the creation of dramatic, planet-scale disruptions which possibly suck the ionosphere up and away from the surface of the planet. Venus Express, a satellite that has been orbiting Venus since April 2006, collects information on the planet's atmosphere, plasma environment, and surface. In January, images from the mission showed the planet is blanketed in high-level clouds known as gravity waves.
"We believe that these waves are at least partly associated with atmospheric flow over Ishtar Terra, an upland region which includes the highest mountains on Venus," Silvia Tellmann from the University of Cologne, Germany, said at the time. "We don't yet fully understand how such topographic forcing can extend to high levels, but it seems likely to be one of the key processes for the generation of gravity waves at high northern latitudes on Venus. The waves may form when a stable air flow passes over the mountains."
Findings were published in the Journal of Geophysical Research.
