Cassini’s Curtain Call

NASA’s unassuming civil servant Cassini has a thing or two to prove. Before graciously accepting an inevitable and long overdue retirement -Cassini   obligingly agreed to traipse through daunting plumes of ice and water vapor, allowing mankind unprecedented insight into ice plumes erupting from the south pole of Saturn’s moon Enceladus.

Eighteen years after launch, seven years en-route to Saturn, eleven years exploring Saturn and her moons, two mission extensions beyond wildest expectations – Cassini has nothing to lose. On October 28 this sentiment meant taking a dive at 31,000 kph to within 45 Km of Enceladus at the south pole, directly into erupting “plumes” of icy vapor.

Below – seven facts about Cassini/Enceladus from earthsky (linked above)

1. Early in its mission, Cassini discovered Enceladus has remarkable geologic activity, including a towering plume of ice, water vapor and organic molecules spraying from its south polar region. Cassini later determined the moon has a global ocean and likely hydrothermal activity, meaning it could have the ingredients needed to support simple life.

2. The flyby will be Cassini’s deepest-ever dive through the Enceladus plume, which is thought to come from the ocean below. The spacecraft has flown closer to the surface of Enceladus before, but never this low directly through the active plume.

3. The flyby is not intended to detect life, but it will provide powerful new insights about how habitable the ocean environment is within Enceladus.

4. Cassini scientists are hopeful the flyby will provide insights about how much hydrothermal activity – that is, chemistry involving rock and hot water – is occurring within Enceladus. This activity could have important implications for the potential habitability of the ocean for simple forms of life. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.

5. Scientists also expect to better understand the chemistry of the plume as a result of the flyby. The low altitude of the encounter is, in part, intended to afford Cassini greater sensitivity to heavier, more massive molecules, including organics, than the spacecraft has observed during previous, higher-altitude passes through the plume.

6. The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions — or a combination of both. The answer would make clearer how material is getting to the surface from the ocean below.

7. Researchers are not sure how much icy material the plumes are actually spraying into space. The amount of activity has major implications for how long Enceladus might have been active.

Linked below, NASA’s Jet Propulsion Laboratory definitive guide to Cassini.

Ponder the exquisite magnificence of Cassini’s accomplishments.

Work Views

I love my line of work. Just when I think I’ve seen it all, along comes a twenty five foot circus marionette dangling wine faeries from each arm. Kicking myself for not capturing clearer images – understand it required considerable effort to take pictures at all – we had work to do. As upwards of 200 guests poured into the concourse of Vancouver Public Library, our service staff offered an empty wine glass to each guest. “David” the marionette from Underground Circus dropped wine faeries from above, filling out-stretched glasses.

2015-10-25 19.17.21

2015-10-25 19.32.27

Halloween Asteroid

Dubbed the Halloween asteroid, media touts 2015 TB145 as the “largest known asteroid to pass Earth until 2027”. At 1:05 pm ET on October 31, 2015 TB145 will pass Earth’s orbit at a distance of 498,896 Km. Estimated to have a diameter somewhere between 4 – 5 hundred meters, science isn’t sure if it’s an asteroid or comet. We know it kicks ass – traveling at 126,000 Km an hour. What we didn’t know before October 10 was that it even existed.

On October 10, 2015 Pan STARRS 1 telescope in Hawaii identified 2015 TB 145. Practically overnight media gave birth to the “Halloween Asteroid”, I suppose no one could blame them, it possesses a certain degree of dramatic flair. Over the past few days “have you heard about the Halloween asteroid?”  spewed from more lips than I could count, unaware their small talk just rang my space bell.

Unable to stop if I tried, ” it was only discovered 3 weeks ago by Pan STARRS and as of today is one of 1,633 PHAs, potentially hazardous asteroids over 100 meters within 100 lunar distance of Earth. A lunar distance is the distance from Earth to the Moon or 384,401 Km, and the Halloween asteroid will miss us by 1.3 lunar distance”.  – befuddled small talkers manage – “oh my, you know a lot about this stuff”. “Yes, I suppose I do”.

Don’t get me wrong, nothing makes me happier than awareness of all things space. Every so often media latches onto space news deemed worthy of a headline or two. What’s sad is the lapse of wonder in between, a seemingly oblivious regard for the cosmos. TB 145 won’t squash Halloween festivities, but would it kill us to ponder our fragile existence?

Artist's concept of a large asteroid passing Earth, via Shutterstock.

Artist’s concept of a large asteroid passing Earth, via Shutterstock.