Definitely a highlight of my rather long day today was seeing these images taken by the ESA’s Mars Express robotic probe. The images depict the Echus Chasma series of canyons mentioned in the title, and I find them absolutely stunning. Planetary geologists believe that these chasms were formed by flowing ground water, and that they were carved over thousands of years. More images:
I absolutely geek out seeing the surface of Mars in such incredible detail. Our base of knowledge for Mars is growing rapidly, and it seems that with the Phoenix Mars Explorer, Mars Surveyor, and ESA’s Mars Express we have a trifecta of data and images streaming to us from the red planet.
Catching up on the deluge that is my RSS reader lately, I came across this image from APOD of the Caloris basin (also called Caloris Planitia) on Mercury recently snapped by the Mercury Messenger robotic explorer. It’s huge, and one of the largest impact basins from an asteroid-sized object in our solar system. The basin measures over 1,500 km across. The image above is a false color image in order to enhance details not visible in a true color image. The yellowish object dominating the image is obviously the impact crater of the Caloris basin, but the orange spots above denote volcanic activity on Mercury, which is new evidence provided by Messenger that the smooth plains of Mercury are actually lava flows.
I had previously written about Mercury and NASA’s Messenger mission here and here.
The Phoenix Mars mission team released some incredible news on June 20th. The Phoenix Mars explorer, since landing on Mars on May 25th, had definitively established that the white material exposed with its digging tool earlier is in fact frozen water. Phoenix had found water ice just below the Martian regolith. That was a significant part of the mission, and to accomplish it so quickly and efficiently is a big win for NASA, JPL, and the whole mission team. The proof is represented in the image above. If you watch the image you see the white material begin to shrink and disappear. That is called sublimination, which is the transition of an element or compound from solid to gas without the intermediary liquid step. Given the atmospheric conditions on Mars, you are seeing evidence above of the frozen water on mars subliming.
Identifying water ice was the first important step in the mission team’s “follow-the-water” mission framework. Knowing that they are working with water ice now triggers a series of analyses that will help identify the mineral components and chemicals in that water ice, and also look for any organic materials. This investigation will help determine if the conditions just below the Martian surface are conducive to microbial life, and if that life exists or has existed on Mars.
Fun for me on this Father’s Day where I was told to do whatever I wanted this afternoon. I did the right thing and began using the Impact Calculator from Edward Gomez and Jon Yardley to create simulated asteroid impacts and measure the resulting destruction. The image above is the crater created by an asteroid made of iron and measuring 15,000 meters wide which impacted at 27 degrees in excess of 60km/second. That crater is over 1700 meters deep (that is the Empire State Building sitting in the center to provide some perspective).
I came across the Impact Calculator at OrbitingFrog.
The Cassini robot explorer, written about here before, will hit the four year mark on June 30th in the relentless pursuit of its prime mission to explore Saturn and its many moons. After June 30th Cassini is operating in bonus territory, as it was not expected that the probe would last this long or work this well. They call this additional time the “extended mission”. Obviously, everyone is ecstatic as the Cassini mission has been profoundly successful in sending us back invaluable information and images of Saturn (like the one above of Saturn’s rings), as well as the moons Titan, Enceladus, Dione, Tethys, Phoebe and Iapetus. In many ways the discoveries regarding Saturn’s moons has largely overshadowed the many, many findings with regards to Saturn itself.
Following the work of Cassini has been like following your favorite band on tour. Nearly every month the mission team has reported more incredible findings or provided another series of stunning images. This page from the mission website catalogs dozens of events and accomplishments. This year alone Cassini has scheduled over a dozen different flybys to allow the use of the craft’s Visual and Infrared Mapping Spectrometer (VIMS), Ultraviolet Imaging Spectrograph (UIS), Synthetic Aperture Radar (SAR), Ion and Neutral Mass Spectrometer (INMS), and Radio Science Subsystem. Cassini is packed with gear, and it is not only amazing that it all is still working as planned, but that it made it there in the first place. Congratulations to the Cassini-Huygens mission team on the four year anniversary.
NASA engineers have been busy testing robotic mobility prototypes for potential use on future missions to the moon and Mars. The engineers, in full astronaut gear, have been putting the machines through their paces on terrain at Moses Lake, Washington that approximates the mobility challenges of navigating the surface regolith of the moon.
The robotic prototypes tested include the twelve wheeled robotic transport pictured above, as well as a six-legged all-terrain vehicle that can carry large payloads, an autonomous drilling rover and a mapping robot. There is an incredibly large and well-shot image gallery of the testing, and the various robotic vehicles, here that is worth viewing. The public was invited to observe, which is further proof of the efforts that NASA is undertaking to engage the public and enlist their enthusiasm. NASA’s relatively recent adoption of social media as a way to create dialog with the public is an additional indicator of a changed view of the role of the public in space exploration.
Over the past two years astronomers at NASA’s Meteoroid Environment Office have observed over one hundred explosions on the moon’s surface. These explosions are the results of impacts by meteoroids and have measured as powerful as a few hundred pounds of TNT. It is no surprise that the moon suffers impacts, look at the image of the moon’s surface above. What is interesting is the observable frequency of these impacts in the last 24 months, which is quite a bit more intense than astronomers were expecting. This is an important phenomena for NASA to observe and understand as we get closer to the reality of a new effort to send astronauts to the moon and eventually set up a permanent lunar base. Essentially, there is no place on the moon that is impact free, nor is there a time that is less intense for impacts than others. The image below depicts the locations of the recorded impacts since initiation of the program:
The frequency and explosive power of these impacts pose a number of challenges to lunar astronauts, not so much from the risk of a direct hit but more from the risk of a secondary hit by one of the millions of particles that the explosions create and that shoot out from the impact area like bullets. A piece of debris 1 millimeter in diameter could penetrate an astronauts suit and damage equipment.
The first impact was recorded very shortly after the initiation of the moon impact observation program and recorded the strike of a meteoroid about the size of a baseball. Most of these impacts are the result of small meteoroids, some little bigger than a small rock or pebble, but they are traveling in excess of 30,000mph and hit the moon with incredibly violent force. A meteoroid the size of a pebble can create a crater several feet across.
This image is the result of the Mars Phoenix mission team instructing the robotic arm camera to look under the vehicle. What you are looking at is the surface of Mars, and it shows that the Martian soil has been displaced by the landing thrusters on Phoenix to expose what is most probably ice. The simple action of Phoenix landing on Mars has potentially exposed polar ice directly under the vehicle, ice that was covered by a very loose and thin layer of soil.
There is a rumor that when the mission leaders saw this image the first words uttered were “Holy cow!”
Posts lately have been all things solar system, and that is because there is so much going on right now with regards to robotic exploration of Jupiter, Saturn, Mars and the their various moons. It is an exciting time to be a space exploration geek. I just came across the above image taken by the ESA’s Venus Express explorer of a vortex occurring in the southern polar region of the planet. This image was captured by Express back in 2006. I also found an excellent image montage of Express approaching Venus that shows some detail in the cloud covering that surrounds Venus.
Venus Express is essentially a reconfiguration of the ESA’s Mars Express explorer technology and left for Venus back in 2005. The goals for Venus Express are to explore the atmospheric composition and circulation on Earth’s closest neighbor, as well as how the atmosphere interacts with the planet’s surface. Venus is definitely inhospitable, with an atmosphere mostly comprised of noxious gasses and an incredibly hot surface temperature. Surprisingly, given the close proximity of Venus, we still know very, very little about the planet. Venus Express is helping to change this.
The Phoenix robotic explorer has been on Mars now for about 27 hours after an incredibly successful entry, descent and landing. It has been very busy. Incredible images are already streaming to Earth, and those of us geeked out by things of this nature are absolutely riveted. I was excited to discover how many people I know were following @MarsPhoenix on Twitter.
Many images are coming back, and most right now are of the explorer itself and the immediate vicinity as the mission managers check systems and get their bearings. The above image of one of the craft’s landing pads is one of my favorites because that image is of the pad of a man-made robotic explorer sitting on the surface of Mars millions of miles away from Earth, and it was taken in the last 24 hours. Astounding. Even more astounding is this video composite of the Martian surface, terrain and horizon taken by Phoenix today.
We are at just under four hours before Phoenix lands on the surface of Mars. I am checking periodically at the Phoenix mission control website in anticipation of this event. Martian weather is clear and the landing later today is green for go. I suspect there are a lot of very excited and anxious people at JPL right now.
The above animation is of weather on Mars around its north pole from 5/16 through 5/22. The small cigar shaped outline in the upper left quadrant is the planned landing zone.
It’s not just a big day for race fans, its a big day for science and space enthusiasts. In August of last year the Mars Phoenix Explorer left Earth to start its journey to Mars. Its mission is to arrive safely, land on the Martian North Pole, and dig into the soil there begin looking for the building blocks of life. It arrives today at around 4:45PM PDT. Arriving is the hardest part, as now the explorer has to successfully enter the Martian atmosphere (at 12,000mph) using parachutes to slow the rapid descent from 900mph to 250mph, and then fire landing rockets to prevent it from slamming into the Martian surface (see the video above). Its a complex landing, and the mission control team probably hasn’t been sleeping much these last few days, as the last five years of their work culminates today in about seven minutes of anxiety. That’s okay, though, as they have a number of ways they can distract themselves while keeping us updated on the the mission’s progress. For instance, you can follow the Phoenix mission on Twitter and get frequent updates and mission facts. The mission team also has a blog that is full of information and that will be used to post what the mission team is thinking and what Phoenix sees and discovers, as well as an information rich mission website.
So, the entire Phoenix mission is going to be captured for us via an array of online tools. This is incredibly exciting, and it serves to connect us to the exploration and science that NASA leads in a way that is not only meaningful, but also basically real time.
I came across the graphic below this morning and found it really interesting, and startlingly revealing of the fragility of freshwater on the planet. It was put together by UNESCO’s World Water Assessment Program, a program that monitors freshwater issues to properly inform decision making and ensure a comprehensive understanding of the status of our planet’s most valuable natural resource. WWAP puts out a report, the World Wide Development Report, that comprehensively reviews the state of freshwater on the planet. This relates to an earlier post here, What is Important, to Scale, that used a compelling image to represent the proportion of air and water to our planet. The graphic below supports the tenuous nature of freshwater on our planet:
Let’s summarize:
Of the total water on the planet, only 2.5% is freshwater
Of that 2.5%, almost 69% is in glaciers
About 30% is groundwater
Only 0.4% is surface and atmospheric freshwater
Of that 0.4%, 67.4% is freshwater lakes
12.2% is made up of soil moisture
9.5% is in the atmosphere
And just over 10% is in wetlands, rivers and plants and animals
It is interesting to realize how overwhelmingly abundant freshwater is in certain areas of the world, so much so as to be taken for granted, while in contrast how overwhelmingly scarce it is in others. The net is that there is just not that much freshwater on the planet.
The image above is via the Galileo explorer and depicts the volcanic moon Io previously discussed, with its neighboring moon Amalthea. Amalthea is small, and has been misshapen by the incredible volatility of existing in close proximity to Io and Jupiter. It’s a tough neighborhood. As Io is swept by Jupiter’s electromagnetic field huge amounts of material are scoured off of Io and spiraled towards Jupiter. At times Amalthea orbit takes it directly into the path of this material, and the total intensity of the power generated, and it is thought that this has created its intense reddish color and elongated shape.
I came across this composite image last evening and it stopped me in my tracks. Click on it to view larger, it’s worth it. Here is an enormous, active chain of volcanic calderas, named Tvashtar Catena, on Jupiter’s moon Io and we get to see it in amazing detail and color. This is a color intensified composite made up of images taken by Galileo back in 2000 and composited by Ricardo Nunes.
Back in 1999 the Galileo Orbiter snapped some pictures of an active fissure eruption in this caldera. The eruption let loose lava flows that were 30km long and 1.5km high. Here’s a composited image from those pictures:
Io is the most volcanic body in our solar system with its surface literally covered in lava lakes, giant calderas, and active lava flows. The color of Io is mostly due to the huge amounts of sulfur that blanket its surface from all of this activity, which has remained continuous as long as we have been able to observe this moon. We have measured volcanic eruptions on this moon that have created sulfurous plumes 500km high. Because Io orbits closely to Jupiter it is subject to intense electromagnetic radiation. As Jupiter’s magnetosphere rotates it sweeps Io and strips away nearly 1 ton per second of volcanic gases and other materials. Io actually acts as an enormous electrical generator as it moves through Jupiter’s magnetic field developing 400,000 volts across its diameter and generating 3 million amperes that flow across the magnetic field and into Jupiter’s ionosphere.
Incredible images recently of Volcano Chaitén in Chile. This volcano is awake after 9000 years of dormancy, erupting with a fierceness this past week that has sent a plume of volcanic ash 12 miles into the atmosphere and stretching from Chile to the Atlantic ocean. The photo above is of the intense lightning that has erupted in and around the enormous plume, the result of static electricity released in incredible intensity by the density of the ash and the multitude of particles hitting each other and becoming charged. Between the earthquake in China, the cyclone in Myanmar, and the volcano in Chile it is hard to not remember how very much active our planet really is.
Last Monday Stephen Hawking gave a speech at an event commemorating the 50th anniversary of NASA. Hawking has long been a proponent of the value of humans exploring space, and again called for a determined effort by humans to colonize the moon and Mars. He put special emphasis on putting humans into space, and not relying solely on robotic explorers, which is largely driven by the survival of humans, longer term, and is an insurance policy against war, catastrophe, and disaster here on Earth. A great quote from the speech:
“Robotic missions are much cheaper and may provide more scientific information, but they don’t catch the public imagination in the same way, and they don’t spread the human race into space, which I’m arguing should be our long-term strategy. If the human race is to continue for another million years, we will have to boldly go where no one has gone before.”
With regards to life on other planets, Hawking offered three possibilities: that life in the universe, of any type, is rare; that simple forms of life may be common, but intelligent forms of life rare; or that intelligent life typically destroys itself. He went on to say:
“Personally, I favor the second possibility – that primitive life is relatively common, but that intelligent life is very rare. Some would say it has yet to occur on Earth.”
This is unbelievable given the incredibly short time, only 51 years, that humans have had access to orbit around Earth. Via the European Space Agency (ESA) come high resolution images of all of the human-made objects that litter our previously pristine orbit. The image above only depicts those objects in low Earth orbit (LEO). Here are some staggering space garbage facts:
We have put upwards of 6000 satellites into orbit from 4600 orbital launches
400 of these are beyond geostationary orbit or are on interplanetary trajectories
Only 800 satellites of the 6000 are considered operational
Most of the debris has come from explosion events (200) or collision events (10)
As we contemplate commercial orbital access, and look to things like space tourism to make the experience of space travel viable for many more people, this is a difficult reality to process. First, the amount of space debris is only going to increase, and most probably exponentially as the number of active space programs, both private and government, continues to rapidly increase. Second, there is real concern around protecting space vehicles, space stations, and future satellites from imminent collisions with this debris. That adds tremendous cost, complexity and weight to programs that are already stretched for budget and capacity. This is not impossible to overcome, and engineers have been thinking about this issue for awhile given some of the close calls with the Space Shuttle and the ISS. Still, another complexity added to an already very complex process.
Last month the High Resolution Imaging Science Experiement (HiRISE) took some incredibly detailed images of the Martian moon Phobos, as pictured above. It is incredible to me to see something so far away in such crisp detail. The simple reality that there is so much to learn and see is probably the biggest reason I continue to be fascinated by our solar system and by cosmology.
Mars has two small moons, the other being Deimos. Phobos is the bigger of the two, and is about 13 miles across. HiRISE captured a lot of amazing images of this tiny moon, but perhaps the most interesting was a focused shot on the large crater feature named Stickney and shown in the image above. It is the enormous dent on the right side of the moon. If the object that had struck Phobos had been fractionally larger it would very well have blown the moon apart and we would now only know Phobos as a dispersed ring of dust and rock orbiting Mars. Here is an image of the crater in detail:
Those lines emanating from the crater are enormous stress fractures caused by the impact and that run outward across the surface. Surviving this impact was an enormous event, but that pales when compared to the realty that the orbit of Phobos is in slow decay (at 1.8 meters per century) and will eventually bring the moon to crash into the Martian surface. Eventually being about 50 million years from now.
You’ve no doubt already heard of the Large Hadron Collider (LHC) due to the recent resurgence in mainstream media. This is partly because it is a really big deal, connecting us to the earliest moments of the formation of the universe, and partly because some people are worried that when scientists, physicists, and researchers fire it up that it will end reality… and as a result these people are pretty active. That’s not going to happen, the world will not be consumed by tiny black holes. Rest easy.
So, what is the LHC for? It has been constructed to recreate the conditions that occurred just after the Big Bang. In recreating these early moments of the universe we may be able to understand how the first particles were conceived, and thus help us better understand how the universe actually works. The LHC will do this in a very controlled environment, and be heavily measured, recorded and monitored. It will allow us to repeat this experiment with frequency, greatly increasing our ability to study and understand. In short, this is an enormous step towards enlightenment, understanding the nature of reality, and will fill in many of the theoretical blanks that physicists and cosmologists have struggled with for a long, long time. In the name of epistemology, this is a very, very good thing.
LHC Facts:
It is made up of 2000 super conducting magnets
It will utilize the most complex cameras ever made
These cameras will be able to capture impossibly small time horizons
The LHC is the culmination of over two decades of work
Construction involved 7,000 physicists from 80 nations
It is located 175 meters underground and is 27+ kilometers in diameter
Once operational, protons will be accelerated close to the speed of light
Every second there will be 800 million proton collisions
Only a fraction of these matter, and will captured by cameras mentioned above
Particles created will exist for a thousandth, of a thousandth, of a billionth of a second
These collisions will generate heat 1 million times hotter than the core of the sun
To achieve this, the LHC team has had to build an incredibly complex machine of enormous scale. Just one of the superconducting solenoids contains more iron than the Eiffel Tower. There are many of these making up the LHC particle accelerator. The receptors and detectors are housed in giant rooms that are as big as cathedrals. The cost of this project was of such a magnitude (estimates range in the $6 billion and up range) that the United States halted its own Superconducting Super Collider back in 1993.
Excellent video of the LHC and the planned experiments (part 1 of 3):
Earlier this month the European Space Agency posted some high resolution images taken by the ESA Mars Express Orbiter of the ice covered oddity that is Promethei Planum. The images are striking and gorgeous, and depict the seasonal ice coverage of this cratered area that measures as deep as 3,500 meters in places. In the image below on the right is an impact crater, partially covered in ice, that measures roughly 100 km wide and 800 meters deep.
Catching up on my feeds just now I was saddened to see that Arthur C. Clarke, physicist, author, innovator, futurist, and ardent believer in the potential of humanity, has died. He was 90, so the man had a very decent run. Perhaps his most recognized work was 2001: A Space Odyssey, the movie for which just celebrated its 40th anniversary. He leaves behind an enormous legacy of invention, creativity, art, and inspiration having written over 100 books. Enormous. Few have been so profoundly influential to so many, and managed to do it with such consistent style, usually sporting a satin Nehru jacket and tanned from the beaches of his home in Sri Lanka. For me, Arthur C. Clarke is the Yin to Philip K. Dick’s Yang. A couple great quotes from Clarke in honor of his passing…
Reflecting on his life:
“Sometimes I am asked how I would like to be remembered. I have had a diverse career as a writer, underwater explorer and space promoter. Of all these I would like to be remembered as a writer.”
A terrific quote on the value of the space program, from 1970:
“The inspirational value of the space program is probably of far greater importance to education than any input of dollars… A whole generation is growing up which has been attracted to the hard disciplines of science and engineering by the romance of space.”
Absolutely stunning imagery of the recent fly-by of Saturn’s moon Enceladus by Cassini presented in a photo animation. You will find little mention of this in the news, and that is mostly because the news does not care. Lost opportunity for the news. We’ve investigated the robotic Cassini probe here before, and it continues to be very, very busy. On March 12th Cassini flew within 30 miles of Enceladus, approaching from above Enceladus’ north pole and thus seeing the moon as a crescent. Some facts on this beautiful moon:
Enceladus is very bright, reflecting nearly 100% of the light that strikes it
This is because we believe it is almost entirely covered in water ice
It’s surface is considered to be geologically young at less than 100 million years old
There is evidence indicating that the interior of the moon may still be liquid
It is about 500 km wide, or roughly the width of the state of Arizona
Enceladus is known as the “geyser moon” because of enormous eruptions
These are created by the release of energy caused by frictional geothermal heating
More on Enceladus and Cassini’s observations here, here, and here.
A fascinating image. On the left is all of the water on Earth, roughly 1.41 billion cubic kilometers (including oceans, ice, lakes, rivers, ground water, clouds… etc) proportionally represented by the blue marble sitting over Italy. On the right, all of the air in the atmosphere, roughly 5,140 trillion metric tonnes, proportionally represented by the pinkish marble. I would have thought both to be somewhat larger, the reality being that we only have a tenuously thin skin of both water and air.
I found this to be quite surprising, a bit startling, and a little scary.
Image and story via Dan Phiffer, who tests the mathematical veracity of these proportional representations.
The universe is inconceivably vast and empty and we are incredibly isolated here on our little blue speck of dust. This cold, hard reality is an abstraction to most of us because as far as we’re concerned, we’ve got it pretty good. This video is along the lines of the one I posted earlier in the week that contrasts Earth against some impossibly large celestial bodies elsewhere in the universe. More fuel for universal irrelevancy.
Video found via Western Paradigm, a smart and superbly generalist blog I recently discovered.
Pretty incredible, really, just how seemingly microscopic not only our lovely planet, but our entire solar system is when contrasted against the largest known star in the universe, VY Canis Majoris. This star is a hypergiant located about 5,000 light years from Earth. VY Canis Majoris is so enormous that a human walking on its surface at a normal pace of 3mph for 8 hours per day would take 650,000 years to circumnavigate. It would take 2 years 11 months to complete the same task here on Earth. The volume of VY Canis Majoris is nearly a billion times that of our own Sun.
I have posted previously about the planet Mercury, so I was excited to learn that the robotic Mercury research spacecraft Messenger had sent back it’s first image of the planet, the first since Mariner 10 visited Mercury 30 years ago. Messenger stands for the MErcury Surface, Space ENvironment, GEochemsitry, and Ranging mission.The image above was was taken on January 11 as Messenger approached Mercury (at just over 1 million miles from the planet). Scheduled for Monday is a pass at about 125 miles over Mercury’s surface. The plan is for Messenger to make two more close passes (in October 2008 and September 2009) before settling into orbit in March of 2011 and initiating its mission of mapping the surface of Mercury in detail. And in color.
Mercury is the fastest planet in our solar system, and the maneuvering that Messenger will have to do (see graphic below from the Messenger website) to comfortably settle into an observational orbit is complex. It involves the three flybys mentioned to help the craft build up enough speed to match Mercury as it settles into orbit, called “Mercury Orbit Insertion,” or MOI. Messenger will also use a series of trajectory corrections and deep space maneuvers achieved by the controlled firing of its thrusters.
Over the course of his life, Stephen Hawking has made a number of sharp and pointed comments with regards to humanity. One of the most memorable for me would be:
“It is not clear that intelligence has any long-term survival value.”
Stephen Hawking
Today he celebrates his 66th birthday. The man is beyond remarkable, and ranks up there with Carl Sagan as an inspiring astrophysicist who has made his life’s work making cosmology understandable and of value to the rest of us. From his limited physical state, the man has tirelessly worked to broaden our understanding of the universe we live in, and the physics of that reality, in ways that are beautiful and poetic while eschewing complex technical descriptions. He also has a terrificly dry sense of humor which he wields at every opportunity. His approach to life is probably as simple as stated in this statement, one we could take the time to consider:
“When one’s expectations are reduced to zero, one really appreciates everything one does have”
Stephen Hawking
More about my favorite living cosmologist here, here, and from YouTube, Stephen Hawking lectures on the origins of the universe.
This story started back in 1979 when the robotic space explorer Pioneer 11 did a fly-by of Saturn. This was followed a year later by Voyager I, and again in 1981 by Voyager II. These craft sent back primitive but compelling images, obviously far beyond anything we had yet seen from Earth, that created more questions than answers and compelled a generation to learn more. Now, Pioneer and the Voyager twins only captured images as they slingshot through the solar system on their way out as emissaries of humanity, so to speak. It would not be until 2004 that we would again visit Saturn, and this was when the robotic probe Cassini settled into Saturn’s orbit, the first craft to do so. Officially named the Cassini-Huygens, it is an international collaboration between three space agencies (NASA, ESA, and the Italian Space Agency) with 17 nations contributing to the building of the craft. There is an army of 250 scientists throughout the world studying the telemetry being beamed back to Earth. One of them is Carolyn Porco, a planetary scientist and leader of the Cassini mission who gave an excited, emotional, and amazing presentation at TED earlier this year. Definitely watch it. She showed some amazing images of Saturn, like the one here:
This Image was taken by Cassini as Saturn eclipses and is backlit by the sun. Stunning. Her focus, though, quickly moved to the moons surrounding Saturn and what Cassini-Huygens had discovered. The moon Titan stole the show, as Cassini dropped the Huygens probe to the surface to end decades of speculation of what that surface might be like. It has been a successful mission, and Huygens has sent back incredible imagery of an environment not that much unlike Mars, but with characteristics also quite Earth-like. Carolyn’s excitement by the implications of the imagery was readily apparent. The image below is one of my favorites taken by Cassini and is Saturn’s moon Tethys. That large crater that dominates the image is called Odysseus and it is about 400km across, roughly 1/25th of Tethys’ surface. On exactly the other side of Tethys is a series of large trenches cut into the moon’s surface and these were most likely the result of the impact that created the Odysseus crater. That’s cosmological drama.
Some intersting facts about Cassini-Huygens and Saturn to drop into conversation this week:
- The total cost of the Cassini mission will be about $3.27 billion ($2.6 billion from the U.S.)
- More than 5000 people worldwide have worked on or contributed to the Cassini mission
- Saturn averages about 890 million miles distance from Earth
- Cassini traveled nearly 2.2 billion miles to get to Saturn slingshotting off other planets
- Traveling at the speed of light you could make it to Saturn in 84 minutes
- Cassini took six years and eight months to reach Saturn
- On the way it flew by and took images of Earth, Venus, and Jupiter
- The atmosphere of Saturn is primarily hydrogen and helium
- Saturn is a gas giant (made up mostly of gas) and is less dense than water
- That means that in a large enough swimming pool, Saturn would float
- Saturn has a core made up mostly of rock and ice with a radius of about 3700 miles
- At its poles Saturn exhibits auroras similar to those on Earth
It was 1980. I was 11. PBS aired the Carl Sagan documentary “Cosmos” which would go on to be viewed by over 600 million people worldwide, becoming the most viewed PBS documentary of all time. For many of us, this was our introduction to the history of the universe, to astrophysics, and to planetary science. I remember being totally riveted. I remember thinking that Carl Sagan was cool.
I still think he is cool, but I had not thought much about him over the years. I was sad when I learned that he had died in 1996 at the age of 62, but beyond that had not really thought much more about how important an influence he was on me when I was younger. I believe that my love of the planets and my passion for learning about the universe started with watching Carl Sagan on television while laying on the family room floor when I was 11.
In a strange but happy coincidence, a friend loaned me a copy of Sagan’s first book “Contact” which I had not yet read, and somebody sent my wife a Carl Sagan clip from Youtube. This was within a 24 hour period. For me, it signaled the beginning of a Carl Sagan rediscovery, which I have been happily conducting for the last couple of days. Here is a choice Sagan quote that I came across:
“If you want to make an apple pie from scratch, you must first create the universe.”
Carl Sagan (1934-1996)
Youtube has several segments of both “Cosmos” and another popular Sagan documentary, “Origins.”
It’s the weekend and that means I have set aside the hammer and the bullhorn, if only for now, and seek the distraction of cosmology and astrophysics. Good times. This is not so much an update as more the sharing of sun facts recently found in the latest issue of Good magazine. If you don’t read Good, you should. Good is really, really good. One of the things that Good does in each issue is provide informational graphics on a number of interesting topics. In the latest issue they offered up some detail on our very own sun, which I add to my post on the sun of some weeks ago:
- In 1 second the sun produces energy to meet the needs of our planet for 500,000 years
- It takes eight minutes for light from the sun to reach the Earth
- Solar energy hitting the Earth every second is equivalent to 4 trillion 100 watt light bulbs
- Solar energy hitting one square mile each year is equivalent to 4 million barrels of oil
- Only 1% of the electricity generated in the United States is from solar power… 1%!
These facts are nothing new, and yet we still struggle to create momentum behind solar energy in this country. Old habits die hard.
I picked up that phrase in conversation the other day and it made me curious. I assumed that “retrograde” has its roots in the observable physical behavior of a planet or star as seen from Earth. Beyond that assumption, I did not really know what that meant. Doing a little research, it turns out that the planet Mercury will be entering retrograde on October 11th/12th (depending on your source). The word retrograde applies, in astrology, to the apparent backward motion through the zodiac of a planet. This is an observable phenomenon from Earth, and dates back to the third millennium BCE when the Sumerians made astrological observations of celestial bodies appearing to move backwards. In reality, they were moving more slowly due to the relationship in their rotational axis to that of the Earth and the other observable celestial bodies, but appeared to be moving backwards. The result of these visual relationships is retrograde motion. The 1947 “Encyclopedia of Astrology” by Nicolas DeVore describes this retrograde motion as:
“like the effect of a slow-moving train as viewed from another train traveling parallel to it but at a more rapid rate, wherein the slower train appears to be moving backwards. However, in the case of the celestial bodies it is not a matter of their actual speed of travel, but of the rate at which they change their angular relationship.”
I do not subscribe to astrology, but I do believe that most of what drives astrological definition is based on the actual physical observations of the relationship between celestial bodies in the sky. All of that to say, the physics of the stars and planets could not initially be explained by humans in scientific terms, so we were left to describe this phenomena in ways that we could understand.
It turns out that all of the planets exhibit retrograde motion as seen from Earth. The Sun and the Moon do not, but this is due to the rotational relationship of each to the Earth (the Earth revolving around the Sun and the Moon around the Earth). This motion be distinctly different from what is normally observed, it has been ascribed dramatic significance as it relates to our existence on Earth. Mercury has been of particular astrological significance when entering a retrograde period, as the mythology assigns the messenger of the gods influence over our terrestrial communications and commerce. Entering this retrograde period, Mercury has the potential to wreak havoc on our Earthly interactions with each other. Those who believe in astrology portend chaos for us during these periods.
Now, more about Mercury. As mentioned above, Mercury has been observed in the sky as long ago as the third millennium BCE. It came to represent the messenger of the gods due to the speed with which it moves across the sky. Mercury has only been visited once by spacecraft when, in 1974 and 1975, NASA’s Mariner 10 did three flybys allowing the mapping of about 40-45% of its surface. We do not know a tremendous amount about the planet closest to the sun, but here is a brief survey of what we do know:
- It is one of four terrestrial planets in our solar system, meaning it has a rocky surface
- Mercury has a higher iron content than any other planet in the solar system
- There is an unstable atmosphere made from helium, hydrogen, oxygen, sodium, potassium and calcium
- The surface has the greatest temperature difference in the solar system, due to its proximity to the Sun
- That difference varies at its extremes by as much as 600° Kelvin
- Mercury takes 88 days to orbit the Sun, and has the most extreme orbit of the planets
- In its orbit, it will get as close as 46,000,000km and as far as 70,000,000km from the Sun
- A rotation of Mercury takes about 58 days
- Mercury is the second densest planet, after Earth, but would be first if not for gravitational compression on Earth
- It has a large iron core that generates a magnetic field roughly 1.1% the strength of Earth’s
- Sunlight on its surface is about 6.5 times that on Earth
- Despite the high surface temperatures, there is believed to be ice on Mercury
- It is believed this ice is in the deep craters and at the poles, as these are not exposed to direct sunlight.
I spent Sunday morning enjoying a great cup of coffee, The Clash, the attention of my wife and baby daughter, and thinking about why we do not have a permanent research base on the moon. As a self-appointed critic of the United States space program, I feel compelled to investigate. Given my recent post on the hard realities of a manned mission to Mars, and knowing that several nations are directing their space programs to the moon, you would think that the moon would have been on NASA’s shortlist these last thirty years. I mean… WE’VE ALREADY BEEN THERE. A few times. The reality is, the moon has not been on the list at all, at least not in a meaningful and substantive way, and our last manned visit to the moon was December 7, 1972. That was the mission of Apollo 17, the last of the six manned Apollo missions (beginning with Apollo 11 in 1969) and the end of a nearly 10 year concerted effort to put American astronauts on the moon. We put American astronauts on the moon. In 1969.
There is movement to reactivate the moon program as, back in 2004, President Bush committed us to a lunar landing no later than 2020. There is also talk at NASA regarding the creation of a permanent moon base. Money for initiating the moon program was cut out of NASA’s budget in 2006, but there is still a drive. The fact that Russia, India and China all have active moon programs, and that Japan just recently launched its first moon probe successfully is re-motivating Washington to put the moon back on the docket. China is committed to having a moon presence by 2024, less than 17 years from now. History has a way of repeating itself, and this is no more true than in the U.S. space program. The working model for the potential American moon program (when it gets re-funded), and for the creation of the base, is our very own 1960’s moon program. The thinking, I suppose, is that if it worked back then it should work for us again. The only problem is that most of the scientists and researchers that made that moon program possible are dead. There is concern that we no longer have the knowledge and expertise necessary to get to the moon successfully and that technology alone cannot make up this deficiency. There is also concern that recreating that knowledge and research will be too expensive. The question begs asking… having already been to the moon several times, and being the first to get there, how do we find ourselves again in a race to the moon? This time the technological playing field is much more flat. That, and there is more than one economic superpower in the race.
During my investigation into the moon program I took the time to actually look at Google moon. They have the equivalent for Mars. There is something amazing about being able to explore the surface of the moon and Mars from the comfort of your living room. I cannot help but feel that tools like these will inspire a whole new generation of scientists, researchers and astronauts. After a thirty year hiatus from not really doing anything beyond repetitive low Earth orbital visits via the Space Shuttle, we need a whole new generation to kick our space program into gear.
Some moon facts to jog your memories of sixth grade solar system studies:
- The moon is an average of 238,855 miles from Earth
- A day on the moon lasts 27.3 Earth days
- A lunar year also lasts 27.3 Earth days
- That is because the orbital period is equal to the rotation period
- Surface temperatures range from -387° F to 253° F, from the dark side to the light side
NASA’s plans for the next twenty years is to play out something like this:
- 2008/9 complete the Orion next generation spacecraft
- 2008/9 initiate robotic spacecraft missions to explore the moon
- 2010 the International Space Station is completed
- 2010 the Space Shuttle is finally retired, it will have been in service nearly 30 years
- 2014 first manned moon mission by NASA since 1972 (42 years)
Science fiction, and the planet Mars as a preferred antagonist, maps directly to our ability over the second half of the 20th century to improve our understanding of the neighboring red planet. Things really began to click in 1964. It was then that Mariner 4, sent from Earth to Mars, did a close proximity fly-by of the planet and snapped some photos. Like this one:
Really, at the time scientists were not exactly sure what they were going to see. Despite the fact that Mars had been massively researched via telescope from the comfort of Earth, scientists still harbored science fiction induced anxiety about what Mariner might reveal. Old, abandoned and decayed cities? Signs of water? Signs of great alien civilizations? What they saw is pretty much like the image above, and though without the excitement of alien civilization, nonetheless exciting for the Mariner 4 mission team. Granted, space agencies (NASA and ESA) are working overtime to establish that Mars did, in fact, once support life and to find some sort of fossil evidence of this Martian life form. The Chinese and Japanese are getting into the Mars game, with rumors that India and its fledgling space program are as well. Russia wants to get back into Mars exploration after its success in the 1970’s. This is not what I am talking about, though. We will continue to send a proliferation of unmanned probes to explore Mars, but we are at an important jumping off point in regards to our neighboring red planet. Since 1964 there have been 16 successful unmanned missions (and 23 failed missions) to Mars. NASA has a manned mission to Mars in the offing and scheduled for sometime in the range of 2015-2020… budgets permitting. We are closing in on commercial space flight with the advent of the X Prize and Richard Branson’s partnership with Burt Rutan for Virgin Galactic. There is going to be a space hotel for the families of the astronauts on the International Space Station to stay at when they are in town, just kidding… but there is talk of a space hotel. All of this activity, and while it may not have much directly to do with Mars, it is critical. This is because we are increasing our presence and access to orbit around Earth. Easy access to orbit means that the development of an orbital launch position for Mars voyages could come together relatively quickly. Orbital launch positions greatly ease the launch requirements for getting to Mars. Taking off from Earth’s surface is essentially cost prohibitive for such a mission. Launching from orbit is like sending off a cruise ship, so to speak.
So about the time most of us are getting real serious about retirement, humanity will be getting real serious about really visiting Mars. Conservatively, by the time humans are walking on the surface of Mars some sixty years will have passed since Mariner 4 did the first fly by in Mars orbit. Sixty years. We’re talking somewhere around 2025, hopefully sooner… like the 2015-2020 prescribed by President Bush. The effort to send a manned flight to Mars will have spanned my entire life. I guess it already has. Here is some interesting information about that first manned flight to Mars:
- Scientists estimate a one-way transit time to be in the range of 190-225 days
- Planning is for a surface mission of 30-90 days, putting the round-trip at 410-610 days
- For a crew of five astronauts for this duration 6,150-9150 meals will be required
- Food may be sent ahead and pre-positioned on Mars for the return trip
- What if they cannot find it?
- Assuming 1 gallon of water/astronaut per day yields needs of 2050-3050 gallons of water
- Water sources will have to be supplemented by water purification and condensation capture
- There is concern about the dust on the surface of Mars damaging the landing craft
- To enhance communications, they may boost feeds via satellites around Mars and Earth
- As many as 7 supporting unmanned flights may be necessary in advance of the manned mission
- The astronauts will most likely not have the chance to visit any of the robotic rovers already there
- Rough cost estimates put the price of the manned mission around $10-15 billion
