Saturn Spacecraft Samples Interstellar Dust

[Waspie_Dwarf]

Saturn Spacecraft Samples Interstellar Dust

NASA's Cassini spacecraft has detected the faint but distinct signature of dust coming from beyond our solar system. The research, led by a team of Cassini scientists primarily from Europe, is published this week in the journal Science.

Cassini has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. The spacecraft has also sampled millions of ice-rich dust grains with its cosmic dust analyzer instrument. The vast majority of the sampled grains originate from active jets that spray from the surface of Saturn's geologically active moon Enceladus.

But among the myriad microscopic grains collected by Cassini, a special few -- just 36 grains -- stand out from the crowd. Scientists conclude these specks of material came from interstellar space -- the space between the stars.

Source

[Merc14]

How can they tell this is interstellar dust and not dust created within our solar system?

[Waspie_Dwarf]

How can they tell this is interstellar dust and not dust created within our solar system?

From the article:

The tiny dust grains were speeding through the Saturn system at over 45,000 mph (72,000 kilometers per hour), fast enough to avoid being trapped inside the solar system by the gravity of the sun and its planets.

And also from chemical analysis of the dust. Again, from the article:

Importantly, unlike Ulysses and Galileo, Cassini was able to analyze the composition of the dust for the first time, showing it to be made of a very specific mixture of minerals, not ice. The grains all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions. Conversely, more reactive elements like sulfur and carbon were found to be less abundant compared to their average cosmic abundance.

[Merc14]

From the article:

And also from chemical analysis of the dust. Again, from the article:

Thanks Waspie, was reading at work and but wasn't sure how they could differentiate the chemical make-up.

[paperdyer]

It's a shame the probe can't send any of the dust particles back for further analysis.

[BeastieRunner]

It's a shame the probe can't send any of the dust particles back for further analysis.

I had the same thought as well.

[Merc14]

It is such a tribute to the science and engineering teams that Cassini has been flying around the Saturn system since 2004, has made so many unbelievable discoveries already and is still breaking new ground. They will be studying the data gathered by this incredible spacecraft for decades but it will be a sad day when she gets her final orders and makes that last dive into Saturn's atmosphere.

Edited April 20, 2016 by Merc14