Cassini spacecraft obtained this image of Saturn’s cratered moon Dione on last week, June 16, 2015. 

But the best is yet to come; the next moon after Dione on Cassini’s checklist is mysterious Enceladus, where the probe will make a breathtakingly-close pass of only 30 miles (48 kilometers) from the icy moon’s surface. Enceladus is now known to hide a liquid ocean under its icy crust and, through a system of polar geysers the moon is venting salty water vapor into space and mission scientists hope to use this close pass to further study the composition of this vapor!
credit: NASA/JPL-Caltech/Space Science Institute

Rosetta’s comet emitting mysterious signals.

The Rosetta mission has detected a mysterious signal coming from Comet 67P/Churyumov-Gerasimenko. The mission has five instruments in the Rosetta Plasma Consortium (RPC) that measure the plasma environment surrounding the comet. Plasma is a charged gas and the RPC is tasked with understanding variations in the comet’s activity, how 67P’s jets of vapour and dust interacts with the solar wind and the dynamic structure of the comet’s nucleus and coma. But when recording signals in the 40-50 millihertz frequency range, the RPC scientists stumbled on a surprise - the comet was singing, they report. Through some kind of interaction in the comet’s environment, 67P’s weak magnetic field seems to be oscillating at low frequencies.

In an effort to better understand this unique signal, mission scientists have increased the frequency 10,000 times to make it audible to the human ear. First detected in August as Rosetta approached the comet from 100 kilometres, this magnetic oscillation has continued. Rosetta scientists speculate that the oscillations may be driven by the ionisation of neutral particles from the comet’s jets. As they are released into space, they collide with high-energy particles from interplanetary space and become ionised. Because it is electrically charged, the plasma then interacts with the cometary magnetic field, causing oscillations. But to draw any conclusions about this, further work is needed.

You can listen to it here:
https://soundcloud.com/esaops

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Fleet of ships of The Outer Planets Alliance.

• Small fleet of 14 ships, all showing the recognisable orange markings of the OPA. 

• Interplanetary freighter. Works the red routes between Io and Mars.

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Sketched in my Moleskine with pigment liner pens. The fleet was coloured with Copic Markers (I’m addicted to the Chrome Orange marker). The freighter was coloured in Photoshop.

December 5 Update: Watch the Orion spacecraft today, Friday December 5 at 10:30 am in the Cullman Hall of the Universe.

NASA’s new spacecraft Orion, which is designed to eventually take humans to an asteroid and Mars, will undergo its inaugural test flight on Thursday, December 4.

The un-crewed 4.5-hour flight, called Exploration Flight Test-1, is expected to begin around 7 am EDT from Cape Canaveral, Florida, if conditions are right. Orion will orbit Earth twice, covering more than 60,000 miles and reaching an altitude of 3,600 miles on the second orbit—15 times farther than the orbit of the International Space Station. The spacecraft will return through Earth’s atmosphere at a speed of 20,000 miles per hour, which will generate temperatures near 4,000 degrees Fahrenheit on Orion’s heat shield.

The Museum will host a viewing event for the test flight from 10:30–12 pm. Visitors to the Museum can watch along with Curator Denton Ebel as Orion re-enters Earth’s atmosphere and splashes down into the Pacific Ocean.

Learn more about the test flight and about the Museum event

Image courtesy of NASA

Messenger’s Collision Course with Mercury 

Earlier today, the MESSENGER spacecraft that was studying Mercury ended its mission by crashing into the planet. MESSENGER’s objective was to study and understand the first planet in our Solar System. Over four years, MESSENGER exhausted all of its fuel, resulting in today’s collision.

Jonathan Corum of the New York Times published this interactive piece on the MESSENGER spacecraft. It talks about MESSENGER’s mission and what it learned about Mercury.