Tag Archives: Cassini

Posted in Historical • Science

Time, Space and the Dinosaurs

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by Bob Sparrow

Sputnik

I have been fascinated with space from an early age, and as I have mentioned in previous blogs, my teachers always referred to me as the kid who just took up space in school, but that’s another story.  Most who read our blog are part of the generations who have eye-witnessed the exploration of space first hand.

We remember the Russians, back then it was the U.S.S.R., as the first to explore outer space, as opposed to today’s Russian heart-breaking exploration of Ukrainian space. They opened the ‘space age’ in 1957 with the first satellite to circle the earth, Sputnik, which translated from Russians, means ‘satellite’ – hey, it’s not rocket science . . . well, actually I guess it is!  (Note how small Sputnik is in the attached photo).  A few weeks later, they were the first to send a living creature into space, a dog named Laika, but typical of the Russians, they neglected to send ‘poop bags’ with him, so he returned quite messy.  Subsequently, Americans feared they were falling behind in the ‘race for space’, which we were, so after two mulligans, we finally launched a satellite, called the Explorer, into orbit in January 1958.

In 1961 the Russians etched another notch in their ‘space belt’ by being the first to put a human in orbit around the earth, Yuri Gagarin, which in Russian translates to ‘Neener Neener’.   The Russians had a few other ‘firsts’, one of them being sending the first woman into space, although some say she has still not returned.

“One giant leap for mankind”

President, John F. Kennedy in May 1961, in an effort to put an end to Russia’s dominance in space, made a speech that challenged our scientists to land a man on the moon (and get him back safely) before the decade was over.  While most of our generation remembers where they were when they heard that Kennedy had been assassinated, we also remember where we were in 1969 when we watched Neil Armstrong deliver on Kenney’s promise, and walk on the moon, as well as proving, once and for all, that the moon was not made of green cheese (it was a rumor at the time, kids!).

Clearly the moon landings have been the biggest event so far in human space travel, but since then the launching of various satellites and telescopes that enhance communication and observation, as well as explore other galaxies have taken over the headlines.  In 2017 I wrote here about the satellite Cassini, that took nearly seven years to traveled over 4.9 billion miles to Saturn, made nearly 300 orbits of the ringed planet, took over 450,000 photos (Not all of them got Saturn smiling) and then crashed into the planet that it knew so well, and remains there today.

70 x 46 feet. The sunshield is the size of a tennis court

The next big thing in space happened in 2003 with the launching of the Hubble Telescope, which has provided astronomers with countless new observations about the vast regions beyond our solar system.

And now, we have the James Webb Space Telescope, which was just launched in December of last year (2021), and has now reached its final destination about a million miles from earth, where it will now orbit around the sun.  To say the least, astronomers are giddy!  Why?  Because with this giant telescope we can see further back in time than ever before.  OK, if that statement just made you shake your head, here’s a quick study on the space-time continuum that even those who didn’t take up space in school should be able to grasp. Light is not instantaneous, even though it seems that way when you turn on a light switch, but it is really fast; it travels at a speed of 186,000 miles per second.  OK, you still with me? The moon is our nearest celestial body in the universe, a short 238,900 miles away, it takes light about 1.3 seconds to travel from the moon to the earth, so we are seeing what the moon looked like 1.3 seconds ago.  Expanding that same logic, the Virgo Cluster of galaxies is the largest

I think that’s me in there somewhere!

nearby collection of galaxies at about 60 million light-years from the Milky Way. Still with me? The light we see today from galaxies in the Virgo Cluster started on its path toward the earth at the same time as the age of the dinosaurs was ending on Earth. So, if you were in a Virgo Cluster galaxy today, and you had a telescope powerful enough to study the Earth, you would be able to see the dinosaurs roaming the earth.  What?!!!  Yeah, I don’t fully understand it either!  But I’m thinking that perhaps one day they will be able to figure out how some of us old dinosaurs that are roaming the earth today will be able to actually travel back in time!  Naah, I’m not sure I want to relive all that all over again!!

It is mind-boggling, but so fascinating for those of us that are still just taking up space.

 

Posted in opinion

Death Dive

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by Bob Sparrow

As travel stories go, this one is out of this world . . . literally.

If you read this entire blog, I think you’ll find some pretty amazing stuff.  I understand that most people aren’t that interested in astronomy or astrophysics, but I’ve been fascinated with space for a long time; in fact I was told by my teachers early on that I was just taking up space in school. At the time I didn’t understand what they meant – now I do!  I recently finished the best-selling book, Astrophysics for People in a Hurry, by Neil DeGrasse Tyson and my brain still hurts from reading it, but the parts of it that I understood were mind-blowing! So watching what happened last week and learning details about the entire Cassini mission has been riveting for me.

Depending on your astronomical interests, you may have heard about Cassini’s Grand Finale, which took place last Friday.  The $3.3 billion Cassini project was a joint effort between NASA, the European Space Agency and the Italian Space Agency (Don’t ask me why Italy is not part of the European Space Agency), to launch a satellite that would orbit Saturn and send back invaluable information about the ringed planet and its multiple moons. NASA’s Jet Propulsion Lab in Pasadena managed the mission.  Saturn, as I’m sure you’re aware is about 764 times larger than earth.

Cassini, named after the Italian astronomer, Giovanni Cassini, who made extensive discoveries about Saturn, is a satellite, about 22’ x 13’ in size, that launched from Cape Canaveral in October 1997 and, after a little more than 6 ½ years to travel the approximate 1 billion miles, reached its Saturn orbit in June 2004. So for the last 13 years it’s been beaming home miraculous images and scientific data, revealing countless wonders of this planet, its rings and its 6o+ moons. The most interesting of Saturn’s moons are Titan, the only other body in our solar system that has liquid on its surface, and Enceladus the brightest shining body in our solar system which has geysers gushing up to the surface from hidden oceans beneath the surface.

And while there is more technology in our cell phones today than what went into space with Cassini in ’97, it did some pretty amazing stuff over the last 20 years. Part of its mission included the sending of a landing craft to the surface of Titan, Saturn’s largest moon. The landing craft was named, Huygens, after the Dutch astronomer Christiaan Huygens, who discovered Titan. Both Cassini and Huygens lived in the late 1600s. The information that this landing craft gave us about Titan’s similarity to Earth would amaze you.

So after 20 years of sending invaluable data back to Earth, Cassini, they say, simply ran out of fuel, but hey, they got 20 years to the gallon. It does beg the question, were they using regular or supreme? OK, I’ll tell you what fueled Cassini, but you have to promise not to tell anyone else. It was powered by three radioisotope thermoelectric generators, which use heat from the natural decay of about 73 pounds of plutonium-238 (in the form of plutonium dioxide – obviously!) to generate direct current electricity via thermo electrics. But even that doesn’t last forever, especially when you’re traveling for 20 years at an average speed of around 41,000 mile per hour!

Huygens on Titan

The last hours of Cassini’s mission had it doing its final flyby of Titan, which gave it the gravitational nudge toward the surface of Saturn, where it maneuvered between the innermost rings before it finally disintegrates on its way to the surface of Saturn at around 4:55 PDT last Friday morning. The team planned this ending, as they didn’t want Cassini floating around in space with the possibility of running into something else, like one of Saturn’s many moons.  The Cassini mission changed the course of planetary exploration, it was in a sense, a time machine as it has given us a portal to see the physical processes that likely shaped the development of our solar system, as well as planetary systems around other stars.

If you’re the least bit interested in this kind of stuff, a program I saw it on last Wednesday was on the NOVA channel called Death Dive to Saturn; it may be replayed over the next few weeks on some of the scientific channels.  You can also go to the JPL site below to see more details and photos of the end of Cassini’s mission.

https://saturn.jpl.nasa.gov

Total miles traveled by Cassini getting to and orbiting Saturn: 4.9 billion, without an oil change.