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Venus Express Survived Its Dive!

Illustration of ESA's Venus Express aerobraking in Venus' upper atmosphere (ESA)

Illustration of ESA’s Venus Express aerobraking in Venus’ upper atmosphere (ESA)

Having made over 3,000 orbits of Venus over the past eight years, ESA’s Venus Express has (as of May 15) completed its science mission and is now in the final few months of its operational life. With a nothing-left-to-lose attitude, the spacecraft recently made a daring and risky dive down into the upper layers of the planet’s thick atmosphere, coming within 80 miles of Venus’ broiling surface on July 12 — that’s the closest any human-made spacecraft have gotten to Venus since the Soviet Vega balloon-and-lander missions of 1985!

As dangerous as it may have been for the spacecraft, Venus Express survived the encounter and grabbed some valuable data about the planet’s atmosphere along the way. It’s now working its way up to a higher altitude orbit, but there’s no escaping the fact that its fuel reserves are nearly depleted and it will soon be back on its way down into Venus’ atmosphere on a mission-ending, one-way trip.

Read the rest of my article on Discovery News here.

Just Another Hazy Day on Titan

Color-composite of Titan made from raw images acquired by Cassini on April 7, 2014. (NASA/JPL-Caltech/SSI/J. Major)

Color-composite of Titan made from raw images acquired by Cassini on April 7, 2014. (NASA/JPL-Caltech/SSI/J. Major)

The weather forecast for Titan? Cloudy, hazy, and cold — just like every other day! The image here is a color-composite made from raw data captured by Cassini during a flyby on April 7, 2014, and it shows a look at the two main features of Titan’s atmosphere: a thick orange “smog” made of organic compounds created by the breakdown of nitrogen and methane by UV light, and a wispy blue upper-level haze composed of complex hydrocarbons.

Cassini was approximately 19,076 miles (30,700 km) from Titan when these particular images were captured.

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What Happened to Mars?

Mars wasn’t always the cold, dry world that it is today — billions of years ago it likely looked a lot more like Earth, with seas and rivers of liquid water on its surface and a thick atmosphere with air and clouds. But something happened over the course of Mars’ history to transform it from a warm, wet world to a cold, desiccated desert planet, and while there are many viable suggestions as to what process is responsible, no verdict has yet been delivered.

This video, just released by NASA’s Goddard Space Flight Center, shows what Mars might have looked like four billion years ago. As the camera tracks back the clouds gradually disappear, the lakes and rivers turn to rubble-strewn plains and the skies change from blue to pale orange. As we rise above the dust clouds that roll across the planet, we see the first evidence of modern times: NASA’s MAVEN spacecraft, flying high overhead to investigate the mystery of a lost Mars.
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Saturn’s Atmosphere is More Varied Than it Looks, With Tropical “Jungles” and Ammonia “Deserts”

Color-composite image of Saturn's varied cloud bands (NASA/JPL/SSI. Composite by Jason Major)

Color-composite Cassini image of Saturn’s varied cloud bands (NASA/JPL/SSI. Composite by Jason Major)

Saturn might look like a placid beige ball in backyard telescopes but in reality it has very dynamic weather patterns and climates, rivaling the storms of Jupiter and the varied climates of Earth, based on long-term microwave observations by the Cassini spacecraft.

(Yes, microwaves are good for much more than heating up your coffee.)

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“Like L.A. Smog on Steroids” – Cassini Scientists Pick Apart Titan’s Haze

Layers of Titan's atmosphere (NASA/JPL/SSI/J. Major)

Layers of Titan’s atmosphere (NASA/JPL/SSI/J. Major)

Scientists working with data from NASA’s Cassini mission have confirmed the presence of a population of complex hydrocarbons in the upper atmosphere of Saturn’s largest moon, Titan, that later evolve into the components that give the moon a distinctive orange-brown haze. The presence of these complex, ringed hydrocarbons, known as polycyclic aromatic hydrocarbons (PAHs), explains the origin of the aerosol particles found in the lowest haze layer that blankets Titan’s surface. Scientists think these PAH compounds aggregate into larger particles as they drift downward.

“With the huge amount of methane in its atmosphere, Titan smog is like L.A. smog on steroids.”

– Scott Edgington, Cassini deputy project scientist

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Look Into the Blood-Red Eye of Saturn’s Polar Hurricane

The spinning vortex over Saturn’s north pole, imaged by Cassini. (NASA/JPL-Caltech/SSI)

The spinning vortex over Saturn’s north pole, imaged by Cassini. (NASA/JPL-Caltech/SSI)

An incredible 1,200-mile-wide vortex of spiraling clouds swirling above Saturn’s north pole is seen in all its glory in this stunning image from NASA’s Cassini spacecraft, originally captured last year but recently released by NASA on April 29.

Taking advantage of a new orbital trajectory that puts it high above Saturn’s rings and poles, Cassini acquired the near-infrared images used to make this composite back on Nov. 27, 2012. The resulting image is false color — our eyes aren’t sensitive to those particular wavelengths of light — but still no less amazing!

Read the rest of my article here.

The Colors of Saturn’s Northern Skies

Color-composite of Cassini images acquired on 26 Feb. 2013 (NASA/JPL/SSI/J. Major)

Color-composite of Cassini images acquired on 27 Feb. 2013 (NASA/JPL/SSI/J. Major)

Bored by blue? Saturn’s skies sure do have a lot more colors, as seen here in  a color-somposite made from raw Cassini images acquired on Feb. 27, 2013.

With spring progressing on Saturn’s northern hemisphere (a season that takes 7 1/2 Earth years to pass!) the upper latitudes gradually receive more sunlight and thus more solar energy, warming the planet’s atmosphere and driving the upper-level winds and storms.

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