Most people will always speak of end of life on earth from a giant meteorite, bio-weapon (zombiefication) among religious beliefs. no one can see this coming.
The planet Venus has an "electric
wind" strong enough to remove the components of water from its upper
atmosphere, which may have played a significant role in stripping venus of its oceans, according to new results from ESA's (European Space
Agency) Venus Express mission by NASA-funded researchers.
before we move on you should know that Collinson is an author of a paper about
this research published June 20, 2016, in the journal Geophysical Research
Letters.
"It's amazing, shocking,"
said Glyn Collinson, a scientist at NASA's Goddard Space Flight Center in
Greenbelt, Maryland. "We never dreamt an electric wind could be so
powerful that it can suck oxygen right out of an atmosphere into space. This is
something that has to be on the checklist when we go looking for habitable
planets around other stars."
Venus is in many ways the most like
Earth in terms of its size and gravity, and there's evidence that it once had
oceans worth of water in its distant past. However, with surface temperatures
around 860 F (460 C), any oceans would have long since boiled away to steam and
Venus is uninhabitable today. Yet Venus' thick atmosphere, about 100 times the
pressure of Earth's, has 10,000 to 100,000 times less water than Earth's
atmosphere. Something had to remove all that steam, and the current thinking is
that much of the early steam dissociated to hydrogen and oxygen: the light
hydrogen escaped, while the oxygen oxidized rocks over billions of years. Also
the solar wind—a million-mile-per-hour stream of electrically conducting gas
blowing from the sun—could have slowly but surely eroded the remainder of an
ocean's worth of oxygen and water from Venus' upper atmosphere.
"We found that the electric wind,
which people thought was just one small cog in a big machine, is in fact this
big monster that's capable of sucking the water from Venus by itself,"
said Collinson.
Every planet has a gravity field, it is known(though not widely) that every planet with an atmosphere is also surrounded by a weak electric field. While the force of gravity is trying to hold the atmosphere on the planet, the electric force (the same force that sticks laundry together in a drier and pushes electricity through wires) can help to push the upper layers of the atmosphere off into space. At Venus, the much faster hydrogen escapes easily, but this electric field is so strong that it can accelerate even the heavier electrically charged component of water—oxygen ions—to speeds fast enough to escape the planet's gravity. When water molecules rise into the upper atmosphere, sunlight breaks the water into hydrogen and oxygen ions, which are then carried away by the electric field.
"If you were unfortunate enough to be an oxygen ion in the upper atmosphere of Venus then you have won a terrible, terrible lottery," said Collinson, "You and all your ion friends will be dragged off kicking and screaming into space by an invisible hand, and nothing can save you."
The team discovered Venus' electric
field using the electron spectrometer, a component of the ASPERA-4 instrument,
aboard the ESA Venus Express. They were monitoring electrons flowing out of the
upper atmosphere when it was noticed that these electrons were not escaping at
their expected speeds. The team realized that these electrons had b tugged
on by Venus' potent electric field. By measuring the change in speed, the team
was able to measure the strength of the field, finding it to be much stronger
than anyone had expected, and at least five times more powerful than at Earth.
"We don't really know why it is
so much stronger at Venus than Earth," said Collinson, "but, we think
it might have something to do with Venus being closer to the sun, and the
ultraviolet sunlight being twice as bright. It's a challenging thing to measure
and even at Earth to date all we have are upper limits on how strong it might
be."
Such information also helps us
understand other worlds around the solar system.
"We've been studying the electrons
flowing away from Titan [a moon of Saturn] and Mars as well as from Venus, and
the ions they drag away to space," said Andrew Coates, who leads the
electron spectrometer team at University College London in the U.K. "The
new result here shows that the electric field powering this escape is
surprisingly strong at Venus compared to the other objects. This will help us
understand how this universal process works."
Another planet where the electric
wind may play an important role is Mars. NASA's MAVEN mission is currently
orbiting Mars to determine what caused the Red Planet to lose much of its
atmosphere and water. "We are actively hunting for Mars' electric wind
with MAVEN's full arsenal of scientific instruments," said Collinson.
"MAVEN is a robotic detective on this four-billion-year-old mystery of
where the atmosphere and oceans went, and the electric wind has long been a
prime suspect."
Taking the electric wind into
account will also help astronomers improve estimates of the size and location
of habitable zones around other stars. These are areas where the temperature
could allow liquid water to exist on the surface of alien worlds, making them
places where life might be found. Some stars emit more ultraviolet light than
the sun, so if this creates stronger electric winds in any planets orbiting
them, the habitable zone around such stars may be farther away and narrower
than thought. "Even a weak electric wind could still play a role in water
and atmospheric loss at any planet," said Alex Glocer of NASA Goddard, a
co-author on the paper. "It could act like a conveyor belt, moving ions
higher in the ionosphere where other effects from the solar wind could carry
them away."
ESA's Venus Express was launched on
Nov. 9, 2005, to study the complex atmosphere of Venus. The electron
spectrometer was built by the Southwest Research Institute in San Antonio,
Texas, and is led by University College London. The spacecraft orbited Venus
between 2006 and December 2014. After a successful mission that far exceeded
its planned life, the spacecraft exhausted its fuel supply and burned up upon
entry into Venus' dense atmosphere. The research was funded by NASA's MAVEN
(Mars Atmosphere and Volatile Evolution) mission and NASA's Solar System
Workings program.
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