Posts Tagged ‘Solar System’
An afterthought about the adventurous spirit of man.
While the focus on the manned exploration of space has declined significantly since those days of the Apollo missions, the spirit to explore has not diminished. This was underlined in spades by a recent post from the British blog Earth & Solar System that I have been subscribing to since a few weeks ago.
First some background to Earth & Solar System.
This blog reflects the research interests of the Isotope Cosmochemistry and Geochemistry Group at the University of Manchester. In our laboratories we study samples from comets, interstellar dust, interplanetary dust, Mars, the moon and asteroids to understand how the Earth and the Solar System were formed, how they evolved and became what we see today. We study the Earth and its chemistry to understand how it works, its mantle, crust, oceans and how we change it. We want to share and discuss what we find with everyone.
The blog is for sharing science and what we and other research groups discover as we do science in real time. Discussion, questioning and enquiry are good, but politics, and opinion that can’t be backed up by published scientific work are strictly off-limits and will be removed.
Yet another example of why integrity is the only way forward.
Anyway, the recent post that was published came into my ‘in-box’ on Monday and I wanted to share it with you. Primarily because the mainstream media have moved on and there is little ‘news’ about NASA’s Curiosity rover. That’s why this post is so fascinating and it’s reproduced on Learning from Dogs with the permission of Ashley King, the author.
A busy week
Posted on September 3, 2012 by Ashley King.
The past week has seen NASAs Curiosity rover return more amazing images of the Gale crater, fire up its DAN and SAM instruments, and take its first steps towards Mt. Sharp.
The new images, captured using the 100mm telephoto lens of the Mastcam, provide a glimpse of the geological treats that await scientists at the base of Mt. Sharp. Of particular interest has been the identification of an unconformity, where two rocks in contact but of different ages indicate a break in the geological record. Satellite data suggests that the rocks lying below the unconformity contain hydrous minerals whilst those above are “dry”. It appears these rock units formed under very different environmental conditions.
Next, Curiosity had another driving lesson, this time positioning itself over one of the scour marks created during landing. This allowed the rover to continue testing the ChemCam and turn on the Dynamic Albedo of Neutrons (DAN) instrument, which will be used to search for water below the Martian surface. The Sample Analysis at Mars (SAM) instrument, comprising of a mass spectrometer, gas chromatograph and tunable laser spectrometer, was also gently woken up. SAM can measure the abundance of C compounds, H, N and O, elements associated with life, in atmospheric and powdered rock samples. A quick test of some Earth air trapped in the instrument since launch confirmed that it is working well and should soon be ready for Martian samples.
Curiosity has now completed four drives and is heading for Mt. Sharp. However, the first target is Glenelg, a rock outcrop 400m to the east of the Bradbury landing site, where it’s hoped Curiosity will start using its drill. Although the journey will take several weeks, Glenelg contains at least three different rock types that will help scientists piece together the geological history of Gale crater.
Makes a nice change to forget about the goings-on here on Planet Earth!
Some milestones on the age of the solar system.
Forgive me, dear readers, but something light and simple for today. I don’t mean in the sense of the content, far from it, just easy for me to put the post together as it is from a presentation that I gave a year ago.
Here’s a picture of our solar system.
Most of us are reasonably familiar with this visual concept of our solar system, but what of it’s age? That’s much more difficult to embrace in a way that we can relate to.
So let’s use something to represent the age of our solar system, the distance from Phoenix to Payson.
In round terms, Payson is 80 miles North-East from Phoenix. Put another way, that’s 422,400 feet!
So if those 80 miles represented the age of our solar system, what would be the significant milestones on this metaphorical journey?
Phoenix represents the start, the ‘start’ of our solar system some 4.54 billion years ago
It was 1,075,000,000 years before Blue-green algae appeared. That is the equivalent of travelling 18.94 miles from Phoenix North-East along Highway 87. Or looking back, those algae appeared some 3.465 billion years ago.
But on we travel, metaphorically an unimaginable 3,459,800,000 years after the arrival of Blue-green algae until the next milestone; the earliest hominids. In terms of our Highway that’s a further 60.97 miles. Again, looking back that was 5,200,000 years ago.
The sharp-eyed among you will see that 18.94 miles added to 60.97 miles is 79.91 miles. Goodness that’s awfully close to the total distance of 80 miles between Phoenix and Payson! In fact, the 0.09 miles to run is the equivalent of 484 feet!
So let’s look at those last 484 feet.
The first 465.20 feet represents the approximately 5 million years after the earliest hominids appeared before H. sapiens arrived, some 200,000 years ago.
The appearance of Homo sapiens brings us to just 18.6 feet from Payson.
But first, we travel 9.3 feet and see the arrival of dogs, generally regarded to have separated, in DNA terms, from the Grey Wolf 100,000 years ago.
And are you 60 years old? You were born just 0.0669 inches or 7/100ths of an inch from Payson! If my maths is correct (someone please check!) 0.0669 inches is about 34 times the thickness of the human hair! That’s very close to Payson!
Don’t know about you but it puts the age of our solar system into a perspective one might be able to get one’s arms around.
On the scale used above, one inch represents 895.68 years, one foot the equivalent of 10,748.11 years and a mile represents 56,750,000 years.
Anybody want to hazard a guess as to the state of our planet in one further inch?
OK, let me stay more or less on topic and just round things off.
EarthSky website seems to have some great items, including this one.
Ten things you may not know about the solar system
9 ) Pluto is smaller than the USA
The greatest distance across the contiguous United States is nearly 2,900 miles (from Northern California to Maine). By the best current estimates, Pluto is just over 1400 miles across, less than half the width of the U.S. Certainly in size it is much smaller than any major planet, perhaps making it a bit easier to understand why a few years ago it was “demoted” from full planet status. It is now known as a “dwarf planet.”
Go here for the full list of ten items.
Finally, just how far does it all go?
How far do the stars stretch out into space? And what’s beyond them? In modern times, we built giant telescopes that have allowed us to cast our gaze deep into the universe. Astronomers have been able to look back to near the time of its birth. They’ve reconstructed the course of cosmic history in astonishing detail.
From intensive computer modeling, and myriad close observations, they’ve uncovered important clues to its ongoing evolution. Many now conclude that what we can see, the stars and galaxies that stretch out to the limits of our vision, represent only a small fraction of all there is.
Does the universe go on forever? Where do we fit within it? And how would the great thinkers have wrapped their brains around the far-out ideas on today’s cutting edge?
For those who find infinity hard to grasp, even troubling, you’re not alone. It’s a concept that has long tormented even the best minds.
Over two thousand years ago, the Greek mathematician Pythagoras and his followers saw numerical relationships as the key to understanding the world around them.
But in their investigation of geometric shapes, they discovered that some important ratios could not be expressed in simple numbers.
Take the circumference of a circle to its diameter, called Pi.
Computer scientists recently calculated Pi to 5 trillion digits, confirming what the Greeks learned: there are no repeating patterns and no ending in sight.
The discovery of the so-called irrational numbers like Pi was so disturbing, legend has it, that one member of the Pythagorian cult, Hippassus, was drowned at sea for divulging their existence.
A century later, the philosopher Zeno brought infinity into the open with a series of paradoxes: situations that are true, but strongly counter-intuitive.
In this modern update of one of Zeno’s paradoxes, say you have arrived at an intersection. But you are only allowed to cross the street in increments of half the distance to the other side. So to cross this finite distance, you must take an infinite number of steps.
In math today, it’s a given that you can subdivide any length an infinite number of times, or find an infinity of points along a line.
What made the idea of infinity so troubling to the Greeks is that it clashed with their goal of using numbers to explain the workings of the real world.
To the philosopher Aristotle, a century after Zeno, infinity evoked the formless chaos from which the world was thought to have emerged: a primordial state with no natural laws or limits, devoid of all form and content.
But if the universe is finite, what would happen if a warrior traveled to the edge and tossed a spear? Where would it go?
It would not fly off on an infinite journey, Aristotle said. Rather, it would join the motion of the stars in a crystalline sphere that encircled the Earth. To preserve the idea of a limited universe, Aristotle would craft an historic distinction.
On the one hand, Aristotle pointed to the irrational numbers such as Pi. Each new calculation results in an additional digit, but the final, final number in the string can never be specified. So Aristotle called it “potentially” infinite.
Then there’s the “actually infinite,” like the total number of points or subdivisions along a line. It’s literally uncountable. Aristotle reserved the status of “actually infinite” for the so-called “prime mover” that created the world and is beyond our capacity to understand. This became the basis for what’s called the Cosmological, or First Cause, argument for the existence of God.
Think I need to lie down now!
The passing of an asteroid.
This has been very widely reported but not seen by me until a few moments ago.
Here’s how the BBC is reporting Asteroid 2005 YU55.
Giant asteroid to pass near Earth
An asteroid that is 400m (1,300ft) wide will pass by the Earth on Tuesday, closer to it even than the Moon.
It poses no danger to the Earth and it will be invisible to the naked eye.
Asteroid 2005 YU55′s closest approach, at a distance of 325,000km (202,000mi), will be at 23:28 GMT. It is the closest the asteroid has been in 200 years.
It is also the largest space rock fly-by the Earth has seen since 1976; the next visit by such a large asteroid will be in 2028.
The aircraft-carrier-sized asteroid is darkly coloured in visible wavelengths and nearly spherical, lazily spinning about once every 20 hours as it races through our neighbourhood of the Solar System.
It will trace a path across the whole sky through to Thursday.
The NASA details may be found here.
And an interesting video on the passing of this rather large rock at 23:28 UTC today, November 8th.
Yesterday’s post It’s all we have showing the famous Earthrise picture taken from Apollo 8 generated a lovely follow-up.
One of the comments was from Mike Turner who wrote,
It’s all we have and it’s so insignificant!
The Pale Blue Dot
Mike included a link to an entry on WikiPedia about the tiny, small dot of light in the universe that is Earth, shown in a photograph taken by spaceship Voyager 1 from the edge of the Solar System on February 14th, 1990. Here’s that photograph,
Can you see our planet home? Earth appears as a tiny dot (the blueish-white speck approximately halfway down the brown band to the right) within the darkness of deep space. In a 2001 article by Space.com, STScI‘s Ray Villard and JPL‘s Jurrie Van der Woude selected this photograph as one of the top ten space science images of all time.
Carl Sagan later wrote about his deep feelings about this photograph. That was almost 20 years ago and, as I reflected just a few days ago, human insanity still seems alive and well; it’s about time that the majority of us recognised the fragility and vulnerability of where we live.
Sagan’s words are reproduced here and should be read by every inhabitant of this planet.
From this distant vantage point, the Earth might not seem of particular interest. But for us, it’s different. Look again at that dot. That’s here, that’s home, that’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. [my italics, Ed]
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known.
You may also wish to watch this video.
Thanks Mike for prompting this piece.