There are a handful of known currently tectonically active objects in the solar system: Earth, of course, plus Saturn’s moon Enceladus, Neptune’s moon Triton, Jupiter’s moon Io (the actual most active body known) and (most likely) Jupiter’s moon Europa.
And now we may be able to add Venus to that list. New evidence strongly suggests there are currently active volcanic vents on the surface of Earth’s sister planet.
I’m actually pretty chuffed about this. We’ve had tantalizing evidence for years that something is bubbling and brewing just beneath Venus’s surface. The top of the mountain Idunn Mons is clearly hotter than surrounding terrain, for example. Lava flows have been seen to be warm as well, and they are certainly less than 2.5 million years old, and possibly far less. Sulfur dioxide, a known volcanic gas, has been seen to spike in abundance then fade with time, which looks very much like a volcano outgassing (though it could simply be due to shifting winds).
But new results from an old mission provide what may be the most important evidence yet that Venus is still puffing away: The ESA Venus Express probe, which completed its eight-year mission last year, found several hot spots on the surface of the planet, and they were all located in rift zones; radial cracks around a volcano where, on Earth at least, magma is pushing up on the surface and flowing out.
Better yet, these hot spots flashed into existence and then faded away over the course of a few days. This is exactly the sort of behavior you’d expect from ongoing volcanism.
Observing the surface of Venus is difficult because of its thick, opaque atmosphere (a product of a runaway greenhouse effect). The observations were at the limit of what the camera could do, but Venus was accommodating by providing really big temperature spikes: one may have reach over 800° Celsius, 350° higher than the surface average.
The camera’s field of view is large, so the resolution is low, but it’s possible these hot spots may be as small as a square kilometer. All in all, these really sound like lava eruptions to me. I’m no expert, of course, but then the people who did the research are.
Studying Venus is important. In many ways it’s very much like Earth. It’s roughly the same size and mass, which means the same density, and that implies we have similar compositions. So why is Venus so blisteringly different? Compared to us, we can ask, “What went wrong?” Why is its crust so thick? Why did the greenhouse effect run away there, and not here? Why does Venus appear to have a surface that’s everywhere the same age, as if a globally catastrophic event repaved the entire planet?
Looking to other planets to understand our own is a critical part of planetary science, and given the current state of Earth’s atmosphere, it’s something we must do. Together with studying our own planet (something the current Congressional majority is dead set against, for some odd reason) these are matters that are critical to our own survival.
That’s why these new results of an extant volcanic Venus are so exciting. That, plus the more purely scientific reason that it’s just plain cool. Venus gets closer to Earth than any other planet in the solar system, yet still hides many secrets. What more is there to learn about it?
I’ll leave you with this, my episode of Crash Course Astronomy about Venus. I wonder how many of the questions raised in it will be answered in the coming years?
Why is it so many of us are excited about the New Horizons mission to Pluto?
This. This is why.
That video was created by Erik Wernquist, the brilliant mind behind Wanderers, what I consider one of the best paeans to exploration ever made.
And like Wanderers, all the places in the New Horizons video are real. We see Venus; Mars (flying over Valles Marineris; a rift valley that dwarfs the Grand Canyon); volcanoes of sulfur erupting over the moon Io as Jupiter and its Red Spot hove into view; the two-faced ice moon Iapetus, stained with organic compounds, revealing the magnificence of Saturn as we slide by; Uranus, its atmosphere a teal green from the presence of methane; Neptune and its moon Triton, with its geyser-like eruptions of nitrogen blasting into its extremely tenuous atmosphere…
… and then Pluto. As I write this, just over three weeks before the New Horizon probe pierces the tiny world’s region of space, we still only have fuzzy pictures of Pluto, a mere dozen or so pixels across. Astronomers have many ideas on what we’ll see when the spacecraft sends back its images over the staggering vastness of five billion kilometers of solar system, but the bottom line is we don’t know exactly what we’ll find.
If we did, it wouldn’t be exploration.
You can follow along with this journey using the Pluto Safari app, and of course by keeping tabs on the New Horizons website.
This is more than just terra incognita. It’s spatium incognita. Whether you think Pluto is a planet or just the biggest of the Kuiper Belt Objects, it’s a marvelous step in our exploration of the solar system.
And we’ll be seeing it for the very first time in the history of all humanity, very, very soon.
On April 22, 2015, the Chilean volcano Calbuco erupted, providing the most dramatic and awe-inspiring photographs I’ve ever seen of such an event.
On that day, photographer Martin Heck was right on the scene, by happenstance taking time-lapse footage on the neighboring Osorno volcano. When Calbuco went off, he hurriedly set up and shot video that is, no exaggeration, some of the best I have ever seen of any volcanic eruption ever.
Seriously. Make this full screen and high-definition. It’ll blow your socks off.
Wow. There’s a 4K version of this there, too.
Even better, there were no reported deaths or injuries, despite the huge scale of the eruption. It lasted for well over an hour, and launched a plume 10 kilometers into the sky.
Oh, that plume. The superheated ash and gas are buoyant, so they rise rapidly in a column from the volcano’s vent. The cloud cools as it rises and stops rising when it reaches an altitude where its density equals that of the surrounding air. However, the plume below is still pumping material into that spot, so the cooler material spreads out, forming the mushroom cloud shape. Once the eruption stops, the winds sweep the column to one side.
On top of that, the eruption occurred near sunset, so the low Sun illuminated the cloud from the side, adding more drama. The Sun reddens as it sets, and the ash in the air scatters blue light away, making the cloud appear an unearthly red. At the very end of the video, you can see lightning erupt in the cloud, the result of huge static charges that build up when the sharp, glassy ash particles rub against each other in the turbulent rising column, then suddenly discharge their colossal energy.
This is one of nature’s most impressive terrestrial events, and it unfolds here for you to watch in all its terrifying glory.
You can see more of Heck’s amazing work at his site, Timestorm Films.
Tip o’ the caldera to Joe Hanson at It’s Okay to Be Smart.
