Venus Revealed: Probe Discovers Extraordinary Weather System of the Morning Star

Slowly but surely scientists are unraveling an incredible picture of our Solar System with each planet vastly differing from the next, but all featuring it’s own unique and mysterious beauty. The tan highland area in the center of the image left is called Aphrodite Terra, while the faint green circle to the lower right is a deep canyon named Artemis Chasma.

Named after the Roman goddess of love and beauty, Venus is also known as the “morning star” and “evening star” since it is visible at dawn and dusk to the naked eye, appearing as a bright, white disk from Earth. However, closer up, the planet’s cloudy atmosphere creates a process similar to “urban smog over cities.”

Venus is often called Earth's twin as the two planets are close in size, but that's where the similarity ends. The massive clouds that cover Venus create a greenhouse effect that keeps the planet at a sizzling 864°F. Now Venus Express has revealed our “twin” planet to be extraordinarily fast changing 'global weather' on an extremely large scale. Bright hazes can appear in a matter of days that reach from the south pole to the low southern latitudes and then quickly disappear. Venus’ bizarre weather patterns—unlike anything on Earth—has given scientists new mysteries to solve.

At visable wavelengths of light, the cloudy planet appears serene. All of that changes, however, when scientists switch to the ultraviolet, which reveals an exciting, and mysterious dynamic nature. Ever-changing stripes mark the planet, indicating regions where solar ultraviolet radiation is either absorbed or reflected, respectively.

Venus Express has seen some amazing things while monitoring the behavior of the planet’s atmosphere with its Venus Monitoring Camera (VMC). VMC has captured a series of images showing the development of the bright southern haze. Within days, the high-altitude veil continually brightened and dimmed, moving towards equatorial latitudes and back towards the pole again.

Such global weather suggests that unknown dynamical, chemical and microphysical processes are fast at work on the planet. During these episodes, the brightness of the southern polar latitudes increased by about a third and faded just as quickly.

“This bright haze layer is made of sulphuric acid,” says Dmitri Titov, at the Max Planck Institute for Solar System Research in Germany. That composition suggests the existence of a formation process.

At 70 km and below, Venus’s carbon dioxide-rich atmosphere contains small amounts of water vapor and gaseous sulphur dioxide. normally buried in the cloud layer that blocks our view of the surface.

However, as atmospheric process lifts these molecules high up above the cloud tops, they are exposed to solar ultraviolet radiation. This breaks the molecules, making them highly reactive. The fragments find each other and combine quickly to form sulphuric acid particles, creating the think haze.

“The process is a bit similar to what happens with urban smog over cities,” says Titov.

What causes the water vapour and sulphur dioxide to well up in the first place? The team does not know yet. Titov says that it is likely some kind of internal dynamical process in the planet’s atmosphere, but the influence of solar activity has not been ruled out.

The dark markings, especially, remain one of the biggest mysteries of Venus’s atmosphere. They are caused by some kind of chemical species, absorbing solar ultraviolet radiation. However, planetary scientists do not yet know the identity of the chemical involved, but are eager to unlock the mystery as they continue to probe the mysteries of the “morning star”.

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Researchers Grow Heart

How it happened: The catastrophic flood that cooled the Earth

PARIS (AFP) - Canadian geologists say they can shed light on how a vast lake, trapped under the ice sheet that once smothered much of North America, drained into the sea, an event that cooled Earth's climate for hundreds of years.

During the last ice age, the Laurentide Ice Sheet once covered most of Canada and parts of the northern United States with a frozen crust that in some places was three kilometres (two miles) thick.

As the temperature gradually rose some 10,000 years ago, the ice receded, gouging out the hollows that would be called the Great Lakes.

Beneath the ice's thinning surface, an extraordinary mass of water built up -- the glacial lake Agassiz-Ojibway, a body so vast that it covered parts of Manitoba, Saskatchewan, North Dakota, Ontario and Minnesota.

And then, around 8,200 years ago, Agassiz-Ojibway massively drained, sending a flow of water into the Hudson Strait and into the Labrador Sea that was 15 times greater than the present discharge of the Amazon River.

By some estimates, sea levels rose 14 metres (45 feet) as a result.

How the great flood was unleashed has been a matter of debate.

Some experts suggest an ice dam was smashed down, or the gushing water spewed out over the top of the icy lid.

Quebec researchers Patrick Lajeunesse and Guillaume Saint-Onge believe, though, that the outburst happened under the ice sheet, rather than above it or through it.

In a study appearing on Sunday in the journal Nature Geoscience, the pair describe how they criss-crossed Hudson Bay on a research vessel, using sonar to scan more than 10,500 kilometres (6,000 miles) to get a picture of the bay floor.

In the south of the bay, they found lines of deep waves in the sandy bed, stretching more than 900 kilometres (562 miles) in length and some 1.7 metres (5.5 feet) deep.

These are signs that the bay's floor, protected by the mighty lid of ice, was swept by a mighty current many years ago but has been still ever since, they say.

In the west of the bay, they found curious marks in the shape of parabolas twisting around to the northeast.

The arcs were chiselled as much as three metres (10 feet) into the sea bed and found at depths of between 80 and 205 metres (260 and 666 feet).

The duo believe that this part of the bay had icebergs that were swept by the massive current.

The bergs' jagged tips were trapped in the sea bed and acted like a pivot. As the icebergs swung around, other protruding tips ripped arc-like tracks on the bay floor.

Also presented as evidence are deep submarine channels and deposits of red sediment that stretch from land west of Hudson Bay right across the northwestern floor of the bay itself -- both point to a current that swept all before it.

"Laurentide ice was lifted buoyantly, enabling the flood to traverse southern Hudson Bay under the ice sheet," the study suggests.

Previous work suggests the flood was so huge that it affected climate around the world.

The influx of freshwater into the North Atlantic reduced ocean salinity so much that this braked the transport of heat flowing from the tropics to temperate regions.

Temperatures dropped by more than three degrees Celsius (5.4 degrees Fahrenheit) in Western Europe for 200-400 years -- a mini-Ice Age in itself.

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