Tuesday, May 1, 2012

Oh! Cassini!


Cassini captured this incredible shot of Saturn's rings back in 2004.  This is one of many wonderful images included in the short video that came with my recent Solar Walk app update.

A recent update of my beloved Solar Walk App contained a new "movie" made with the App.   The movie is a documentary of the journey of the Cassini spacecraft from the Earth to Saturn.  I have blogged about Cassini before.  It is a mission I have followed since before its launch in 1997.  The movie that came with the app update was a mind-blower for me.

I have always known that Cassini used orbital assists from planets to gain enough speed to make the distant journey all the way out to Saturn.  But, it suddenly struck me how incredible this feat of space flight truly was.  Cassini flew around Venus twice, the Earth once, then used Jupiter to fling itself a billion miles out to Saturn.  I just never thought of it collectively before since it all happened many years apart in the span of time that I have followed the mission.

All total, Cassini has traveled over 2.1 billion miles to date

On April 5 this year Cassini began its 164th orbit studying Saturn and it moons. 

In 2011, Cassini studied a massive storm thousands of miles long as it raged around the cloud-shrouded surface of the planet.  The storm looped the northern hemisphere of the planet's surface over a few days.  Such a storm would have engulfed the entire Earth with unimaginably destructive force.

According to Solar Walk, Cassini flew-by Venus the first time on Day 193 of its mission gaining in speed over 26,000 kilometers per hour.  This gave Cassini enough velocity to make it all the way out to the Asteroid Belt.  But before Cassini flew out that far NASA adjusted it trajectory to fly by Venus again on Day 617 of the mission, over a year later.  This gave Cassini enough force to whip by the Earth and on the Saturn.

I had forgotten that there were protests on the Earth both before Cassini's launch and again over how "dangerously close" the "radioactive" spacecraft came in the flyby.  That all seems so incredibly childish to me now and I remember thinking it was silly at the time.  I was marketing for a bank holding company at the time.  The Solar Walk movie does not mention this, I rediscovered it in the bit of research the movie inspired me to do later.

The movie includes some fantastic photos which can be tapped and brought to full screen, pausing the movie, so you can enjoy Cassini's glorious capabilities.  The Earth flyby afforded Cassini an opportunity to calibrate its cameras.  That took place on Day 672 of the mission.

Cassini maneuvered a flyby of Jupiter for a final gravity assist on Day 1172 of the mission, December 30, 2000, almost two years after passing the Earth.  By this passage of time I was no longer paying close attention to the mission, though the juncture with Jupiter was in the news and I followed things generally.  Again, there were amazing photos but I never saw the ones featured in the movie before.


Cassini snapped a series of images from one of Jupiter's poles.  These were stitched together (as only one-half of the planet is in sunlight at any given time) and included among the awesome pics in my Solar Walk app's new movie on the mission.  I have never seen Jupiter from this angle before and I bet neither have you.

After a 500-day flyby of Jupiter, Cassini finally ventured on to its intended destination.  This part of the mission took longer than the entire journey to date - an additional 1278 days.  During this time, January 2001 to June 30, 2004, I more or less forgot about Cassini.  There wasn't even much news to check on.  The mission silently went through its fifth and sixth year en route.

When the spacecraft finally entered Saturn's orbit in 2004, I watched the news for reports of the first images.  My interest was briefly renewed, though it soon dissolved into all the other things I was otherwise into in my life.

By karmic coincidence, The Atlantic recently brought my attention to Cassini's amazing capabilities with an incredible collection of high-definition raw space video.  Much of it was presented in a time-lapsed nature so that the viewer might quickly enjoy the rings and moons and debris as it is affected within Saturn's powerful gravitational field.

Condensing years of flight into a few minutes of simple documentary was fascinating to me; all the more rewarding because I didn't have to pay anything for this added treat.  It came with an update of an App I bought last year for only a couple of bucks.  A nice surprise which can also serve as an example of the great value of many of these inexpensive Apps on a tablet platform.

Late Note: A Cassini portrait of one of Saturn's many moons, Helene, was featured as the Astronomy Picture of the Day the day after this post.

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