Let’s face it: news about weather on Venus is never going going to be pleasant. Not only does the surface temperature remain a constant 900º F (480º C) with atmospheric pressure about 90 times higher than on Earth, but it rains sulfuric acid and snows metal. We haven’t even been able to send a probe that lasts more than a couple hours. Not exactly a great vacation spot.
Researchers have now discovered that Venus is exposed to extremely massive weather explosions, sometimes multiple times per day. The announcement comes from first author Glyn Collinson at NASA’s Goddard Space Flight Center and was published in the Journal of Geophysical Research.
Collinson et al. analyzed information gathered by the European Space Agency’s Venus Express orbiter, which studies the dynamics and chemistry of the Venusian atmosphere. Venus is subjected to hot flow anomalies (HFAs), and these massive explosions of weather are actually larger than the planet itself. Solar wind, traveling a million miles per hour, doesn’t always move straight away from the sun. Sometimes it becomes tangled in itself and remains in contact with a planet's bow shock (the point where the wind's speed drops from contact with fields surrounding the planet) to create a powerful projection of hot plasma known as an HFA.
Large HFAs also occur near Earth, but our magnetosphere (the area of space surrounding our planet controlled by our magnetic field) shields us from any ill effects. In fact, the charged particles from the solar wind are responsible for creating aurorae, which are extremely pretty. When solar wind hits an HFA at Earth, the magnetosphere is strong enough to actually deflect the wind, even back toward the sun.
Venus, possessing only a tiny magnetosphere, isn’t as lucky. It has an ionosphere, which doesn’t really have much to offer in the way of protection against solar wind. When solar wind hits an HFA at Venus, it is much closer to the surface than the ones at Earth. The force could act like a vacuum and pull layers of the ionosphere away from the planet, potentially rendering it completely defenseless.
Though Venus is basically an uninhabitable wasteland, there is a lot we can use to compare it to Earth. Understanding how space weather affects Venus differently than Earth is a great way to learn about our own magnetosphere and how essential it is for life to exist on this planet. Researchers will also explore how planetary formation proceeded so differently that Earth would have the capability to support life while Venus does not.
Photo credit: NASA/Collinson