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Cassini Marks Ten Discovery-Filled Years at Saturn

Cassini by the Numbers: an infographic of the spacecraft's achievements over the past decade (NASA/JPL-Caltech)

Cassini by the Numbers: an infographic of the spacecraft’s achievements over the past decade (NASA/JPL-Caltech)

Just a week after Curiosity celebrated its first Martian year in Gale Crater and we have yet another milestone anniversary in Solar System exploration: as of 10:48 p.m. EDT tonight Cassini will have been in orbit around Saturn for a full decade!

“There are times when human language is inadequate, when emotions choke the mind, when the magnitude of events cannot properly be conveyed by the same syllables we use to navigate everyday life. The evening of June 30, 2004 was such a time.” 

– Carolyn Porco, Cassini Imaging Team Leader, CICLOPS “Captain’s Log” on June 30, 2014

That’s ten years and over 2 billion miles of discoveries and explorations of our Solar System’s most majestic planet and its incredibly varied family of moons. Over the course of its primary mission and three extended missions, we have been able to get a close-up look at Saturn and its moons like never before, witnessing first-hand the changes that occur as their seasons change. What’s been discovered by the Cassini mission about Saturn has offered invaluable insight into the evolution of our entire Solar System, as well as planets that could be found elsewhere in our galaxy.

“Having a healthy, long-lived spacecraft at Saturn has afforded us a precious opportunity,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California. “By having a decade there with Cassini, we have been privileged to witness never-before-seen events that are changing our understanding of how planetary systems form and what conditions might lead to habitats for life.”

Launched on October 15, 1997, the Cassini-Huygens spacecraft established orbit around Saturn on June 30, 2004 (July 1, UTC).

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Oxygen Isotopes Support Our Moon’s Violent Origin

The "Giant Impact" hypothesis has the Moon formed from an impact between early Earth and a Mars-sized body (NASA)

The “Giant Impact” hypothesis has the Moon formed from an impact between early Earth and a Mars-sized body (NASA)

While it may not be a true “smoking gun” (there have been four and a half billion years of cooling off, after all!) scientists in Germany have found further support for the currently accepted scenario of the origin of our Moon, based on chemical analysis of rocks brought back by Apollo astronauts. (And yes, we really went to the Moon.)

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Fireball Explodes Over Russia… Again

Why does Russia seem to get so many bright meteors? Well, at 6.6 million square miles it’s by far the largest country in the world plus, with dashboard-mounted cameras being so commonplace (partly to help combat insurance fraud) mathematically it just makes sense that Russians would end up seeing more meteors, and then be able to share the experience!

A bolide detonated over Murmansk, Russia on April 19, 2014

A bolide explodes over Murmansk, Russia on April 19, 2014 (Credit: Alexandr Nesterov)

This is exactly what happened early this morning, April 19 (local time), when a bright fireball flashed in the skies over Murmansk in the Kola Peninsula, located in northwest Russia near the border of Finland. Luckily not nearly as large or powerful as the Chelyabinsk meteor event from February 2013, no sound or air blast from this fireball has been reported, and details on the object aren’t yet known (could be a meteor, could be space debris). The video above, captured in part by Alexandr Nesterov from a dashcam, shows the object lighting up the early morning sky. Check it out, and follow me on Twitter for more details as they are released. Heads up!


Cassini Uncovers Even More Evidence for Enceladus’ Hidden Ocean

A concept of the subsurface structure of Saturn's moon Enceladus (NASA/JPL-Caltech)

A concept of the subsurface structure of Saturn’s moon Enceladus (NASA/JPL-Caltech)

It’s been suspected for nearly a decade that Saturn’s 315-mile-wide moon Enceladus harbors a hidden ocean beneath its frozen crust, thanks to observations by the Cassini spacecraft of icy plumes spraying from its southern pole, and now scientists have even more evidence supporting its existence: Doppler measurements of the moon’s gravity taken during Cassini’s flybys show variations indicative of a subsurface southern sea as deep as the Pacific’s Mariana Trench!

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Rings Discovered Around an Asteroid

Artist's impression of the view from the asteroid Chariklo. Credit: ESO/L. Calçada/Nick Risinger (

Artist’s impression of the view from the asteroid Chariklo. Credit: ESO/L. Calçada/Nick Risinger (

We all know that Saturn is encircled by a system of rings, and perhaps you also know about the fainter rings around Uranus, Jupiter, and Neptune. But today, ESO astronomers have revealed a surprising discovery: there are also rings surrounding the asteroid 10199 Chariklo, a small, distant world orbiting the Sun far beyond Saturn.

This makes 250-km-wide Chariklo the fifth world ever found to have rings, after the four planets mentioned previously, and, based on the observations, it could also even have its own moon.

“As well as the rings, it’s likely that Chariklo has at least one small moon still waiting to be discovered,” said Felipe Braga-Ribas of the Observatório Nacional/MCTI in Rio de Janeiro who planned the observation campaign and is lead author on the new paper.

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On the Lunatic Fringe: LADEE’s First Pictures of the Moon

Image of the Moon and stars from NASA's LADEE spacecraft, Feb. 8, 2014 (NASA/Ames)

Image of the Moon and stars from NASA’s LADEE spacecraft, Feb. 8, 2014 (NASA/Ames)

It’s getting so a spacecraft can’t take a decent picture these days without SOMEONE getting in the way! (*Ahem* MOON.) But then it just might be the lunatic we’re looking for…

The image above is one of five that were downlinked by NASA’s Lunar Atmospheric Dust Environment Explorer — aka LADEE (that’s “laddie” à la Mr. Scott, not “lady” à la Jerry Lewis) — and was taken on Feb. 8 with its wide-angle star tracker camera. We see a small portion of the lunar terrain illuminated by reflected light from the Earth from the spacecraft’s position about 156 miles above the Moon, which is about 100 miles lower than the ISS orbits above the Earth.

While not a particularly detailed image of the Moon like something we’d see from LRO, it’s still neat to see it close up and on its night side! The star tracker instrument is mainly a calibration tool for navigation… but that doesn’t mean it’s blind. (Just a wee bit farsighted.)

Read more about this in my Discovery News article.

A Ceres of Surprises: the Largest Asteroid is a Water World

Artist's interpretation of Ceres, the largest object in the main asteroid belt. (NASA/JPL-Caltech)

Artist’s interpretation of Ceres, the largest object in the main asteroid belt. (NASA/JPL-Caltech)

By now you must know about the jets of ice particles blasting out of Saturn’s moon Enceladus, and maybe have even heard about the recent discovery of water vapor issuing forth from Jupiter’s frozen moon Europa. But now we know of another spray-happy world out there: Ceres, which at 591 miles across is our solar system’s smallest dwarf planet but the largest object in the  asteroid belt. New findings from ESA’s Herschel Space Observatory reveal that this diminutive world is jetting water vapor out into space, proving both that it has an icy surface and that water does in fact exist in the main asteroid belt, which stretches out between the orbits of Mars and Jupiter. Read more below: Read the rest of this entry


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