The Kavir desert in Iran, as seen from the International Space Station on Feb. 14, 2014. Credit: NASA.
At first glance, this beautiful swirling view appears like clouds above a large body of water or possibly the eddies of ocean currents. Surprisingly, this is a desert, the Kavir desert (Dasht-e Kavir – literally ‘desert of salt-marsh’) in Iran, and the image was taken by one of the astronauts on the International Space Station.
An annotated version of the image of the Kavir Desert. Credit: NASA
You’ll notice the striking pattern of parallel lines and sweeping curves. NASA explains that the lack of soil and vegetation in this desert allows the geological structure of the rocks to appear quite clearly from space and the patterns result from the gentle folding of numerous, thin layers of rock. “Later erosion by wind and water cut a flat surface across the dark- and light-colored folds, not only exposing hundreds of layers but also showing the shapes of the folds. The pattern has been likened to the layers of a sliced onion,” NASA says.
While a quick look at Google Maps (see image below) shows that most of the region does appear to be sand-colored brown from space, there are regions with blue tints due to the folds and layers in the exposed surfaces, and the image is actually just a small part of the 77,600 square kilometer (30,000 sq mile) desert. It’s a bit difficult to get a sense of scale in the top image since there are no fields or roads to provide a reference, but the width of the image is about 105 kilometers (65 miles).
There is some water in this area, however. In the center of the NASA image is a dark s-shaped region is a lake and a small river snakes across the bottom of the image. The irregular, light-toned patch just left of the lake is a sand sheet thin enough to allow the underlying rock layers to be detected.
Screenshot of Google Maps showing the Kavir Desert in Iran.
Image of the Grand Canyon from the International Space Station on March 26, 2014. Credit: NASA/JAXA Koichi Wakata.
Can you spot the Grand Canyon in this picture? It is surprisingly hard to see. Astronaut Koichi Wakata took this picture on March 26, 2014 from the International Space Station, and thankfully he provided a clue: look in the bottom center portion in the photo.
If you’ve ever stood at this Canyon’s edge or even flew over in a plane, you know how dramatic the view is. From space … not so much.
You may have seen a fake image of the Grand Canyon from space floating around the various social medias last year that looks much more majestic. I won’t share it here, but suffice to say, it’s a doctored up aerial view with a starry sky photoshopped in. The images here are the real view of the Grand Canyon from space.
Earth’s Grand Canyon pales in comparison to Valles Marineris on Mars– the biggest canyon we know of in the Solar System — which is ten times longer and five times deeper than our Grand Canyon here on Earth.
Valles Marineris as seen in this mosaic of Viking orbiter images. Noctis Labyrinthus at the left, Melas Chasma in the middle, Hebes Chasma just left of top center, Eos Chasma at lower right and Ganges Chasma just above center right. Credit: NASA/JPL
Have you heard the terrifying news that the Earth’s poles are going to flip? What does “flipping” mean? And if the Earth’s poles do flip, are we in any danger?
Have you heard the startling news that the Earth’s poles might flip? Perhaps in the response to a close pass from the mysterious Planet X? Are you imagining the entire Earth actually flipping over on its side or rotating upside down, possibly while Yakkity Sax plays in the background? When will this happen? Can this happen?
First, there’s no secret planet hurtling through the Solar System causing chaos and orbital disturbances. So could the Earth spontaneously physically flip over? Some planets have already been tilted and flipped.
Take a look at Uranus. Its orbital tilt is 98-degrees. We assume the planet started with the same tilt as the rest of the Solar System, and some event in the ancient past caused it to fall over. It could have collided with another planet, billions of years ago, or gravitational interactions with other giant planets pushed it over.
And then there’s Venus, its axial tilt is 177-degrees. That’s essentially upside down. Venus is turning in the opposite direction from every other planet in the Solar System. Standing on the surface of Venus, you would see the Sun rise in the West and set in the East. Astronomers don’t know why this happened, perhaps it was gravitational interactions or a collision with another planet.
To actually flip a planet off its axis would take an event so catastrophic that it would devastate the planet. Don’t worry, as far as we know, those kinds of events and interactions stopped happening billions of years ago.
That’s the good news. The Earth isn’t likely to just fall over, or get bashed on its side like an office tower under the might of Godzilla
Schematic illustration of Earth’s magnetic field. Credit/Copyright: Peter Reid
Now what about those magnetic poles. On Earth, they can and do reverse on a regular basis. The Earth is often shown like a giant bar magnet, with a north magnetic pole and a south magnetic pole. Over vast periods of time, the Earth’s north pole becomes its south pole, and vice versa. Geologists measure the magnetic configuration of iron particles in ancient lava flows. in one part of the lava flow, the particles oriented with one magnetic configuration, and then in another, the particles were reversed. It turns out the planet reverses its polarity every 450,000 years, and the last reversal happened about 780,000 years ago. Which means it could happen in the next few thousand years.
If the Earth’s poles did reverse, what would happen to us? If the magnetic field disappeared entirely, the planet would be bathed in radiation from the Sun, which would likely cause an increase in cancer. But the Earth’s atmosphere would still protect us from majority of radiation.
What about mass extinctions? Scientists have wondered if there’s a link between them and magnetic reversals.
Fortunately for us, there doesn’t seem to be any connection. Whenever geomagnetic reversals happened in the past, it didn’t devastate life on Earth. So don’t worry about it.
There is a pretty good chance it won’t happen in our lifetime, and maybe not for hundreds of thousands of years. And even if the Earth’s poles flip, it wouldn’t be the end of the world. You might need to take a sharpie to your compass though.
Climate change is one of the defining issues of our time. So begins the latest report by the U.S. National Academy of Sciences and the United Kingdom’s Royal Society. The two institutions agree: climate change is not only indisputable, it’s largely the result of human activities.
The bulk of the 36-page report is presented in a question-and-answer format, making it a good bed-side read. But in case you don’t want to have nightmares about surging temperatures or polar bears alone on breaking ice caps, we’ll leaf through the intriguing points here.
In a forward to the report, Dr. Ralph J. Cicerone, president of the National Academy of Sciences, and Sir Paul Nurse, president of the Royal Society argue that multiple lines of evidence show that humans are changing Earth’s climate. This is now more certain than ever.
They are careful to include a caveat: “The evidence is clear. However, due to the nature of science, not every single detail is ever totally settled or completely certain. Nor has every pertinent question yet been answered.” Areas of active debate include how much warming to expect in the future and the connections between climate change and extreme weather events such as the frequency and intensity of hurricanes, droughts and floods.
Earth’s global average surface temperature has risen as shown in this plot of combined land and ocean measurements from 1850 to 2012, derived from three independent analyses of the available data sets. Image Credit: National Academy of Sciences / The Royal Society
But the first question: is the climate warming? goes without debate. Yes. Earth’s average surface air temperature has increased by about 0.8 degrees Celsius since 1900, and the last 30 years have been the warmest in 800 years. It’s the most rapid period of sustained temperature change in the scale of global history, trumping every ice age cycle.
Recent estimates of the increase in global temperature since the end of the last ice age are four to five degrees Celsius. While this is much greater than the 0.8 degree Celsius change recorded over the last 100+ years, this change occurred over a period of about 7,000 years. So the change in rate is now 10 times faster.
Of course an increase in temperature goes hand in hand with an increase in carbon emissions. Greenhouse gases such as carbon dioxide absorb heat (infrared radiation) emitted from the Earth’s surface. Increases in the atmospheric concentrations of these gases trap most of the outgoing heat, causing the Earth to warm. Human activities, especially the burning of fossil fuels have increased carbon dioxide concentrations by 40 percent between 1880 and 2012. It is now higher than at any time in at least 800,000 years.
And if the rise in carbon emissions continues unchecked, warming of the same magnitude as the increase out of the last ice age can be expected by the end of this century.
The report continues to ask more controversial questions. Take as an example the question: Does the recent slowdown of warming mean that climate change is no longer happening? The short answer is no. Decades of slow warming and accelerated warming occur naturally in the climate system. Despite the slower rate of warming the 2000’s were still warmer than the 1990’s
The new report builds upon the long history of climate-related work from the United Nations’ Intergovernmental Panel on Climate Change. So while some have argued it doesn’t add anything new to the wealth of climate science data available, it does help make that data more succinct and available to the public. Its goal is to help inform decision makers, policy makers, educators and all other individuals.
The report concludes by noting available options to citizens and governments. They can simply wait and accept the losses, they can change their pattern of energy production, they can attempt to adapt to environmental changes as much as possible, or they can seek as yet unproven geoengineering solutions.
No matter which option we choose, one thing remains certain: the Earth is warming at a tremendous rate and we are the cause.
GPM Launch Seen From the Tanegashima Space Center. A Japanese H-IIA rocket with the NASA-Japan Aerospace Exploration Agency (JAXA), Global Precipitation Measurement (GPM) Core Observatory onboard, is seen launching from the Tanegashima Space Center on Friday, Feb. 28, 2014 (Japan Time), in Tanegashima, Japan; Thursday, Feb. 27, EST.. Credit: NASA/Bill Ingalls
GPM Launch Seen From the Tanegashima Space Center
A Japanese H-IIA rocket with the NASA-Japan Aerospace Exploration Agency (JAXA), Global Precipitation Measurement (GPM) Core Observatory onboard, is seen launching from the Tanegashima Space Center on Friday, Feb. 28, 2014 (Japan Time), in Tanegashima, Japan; Thursday, Feb. 27, EST. Credit: NASA/Bill Ingalls[/caption]
NASA GODDARD SPACE FLIGHT CENTER, MARYLAND – A powerful, next generation weather observatory aimed at gathering unprecedented 3-D measurements of global rain and snowfall rates – and jointly developed by the US and Japan – thundered to orbit today (Feb. 27 EST, Feb. 28 JST) ) during a spectacular night time blastoff from a Japanese space port.
The Global Precipitation Measurement (GPM) Core Observatory was launched precisely on time at 1:37 p.m. EST, 1837 GMT, Thursday, Feb. 27 (3:37 a.m. JST Friday, Feb. 28) atop a Mitsubishi Heavy Industries H-IIA rocket from the Tanegashima Space Center on Tanegashima Island off southern Japan.
Viewers could watch the spectacular liftoff live on NASA TV – which was streamed here at Universe Today.
“GPM’s precipitation measurements will look like a CAT scan,” Dr. Dalia Kirschbaum, GPM research scientist, told me during a prelaunch interview with the GPM satellite in the cleanroom at NASA’s Goddard Space Flight Center in Greenbelt, Md.
“The radar can scan through clouds to create a three dimensional view of a clouds structure and evolution.”
GPM lifts off on Feb. 27, EST (Feb. 28, JST) to begin its Earth-observing mission. Credit: NASA/Bill Ingalls
GPM is the lead observatory of a constellation of nine highly advanced Earth orbiting weather research satellites contributed by the US, Japan, Europe and India.
Indeed GPM will be the first satellite to measure light rainfall and snow, in addition to heavy tropical rainfall.
It will collect a treasure trove of data enabling the most comprehensive measurements ever of global precipitation every three hours – and across a wide swath of the planet where virtually all of humanity lives from 65 N to 65 S latitudes.
GPM orbits at an altitude of 253 miles (407 kilometers) above Earth – quite similar to the International Space Station (ISS).
The global precipitation data will be made freely available to climate researchers and weather forecasters worldwide in near real time – something long awaited and not possible until now.
Water and the associated water and energy cycles are the basis of all life on Earth.
Yet scientists lack a clear and comprehensive understanding of key rain and snow fall amounts on most of the globe – which is at the heart of humanity’s existence and future well being on the home planet.
Having an accurate catalog of the water and energy cycles will direct benefit society and impact people’s lives on a daily basis with improved weather forecasts, more advanced warnings of extreme weather conditions, aid farmers, help identify and determine the effects of global climate change.
Researchers will use the GPM measurements to study climate change, freshwater resources, floods and droughts, and hurricane formation and tracking.
“With this launch, we have taken another giant leap in providing the world with an unprecedented picture of our planet’s rain and snow,” said NASA Administrator Charles Bolden, in a NASA statement.
“GPM will help us better understand our ever-changing climate, improve forecasts of extreme weather events like floods, and assist decision makers around the world to better manage water resources.”
“The GPM spacecraft has been under development for a dozen years,” said GPM Project Manager Art Azarbarzin of NASA’s Goddard Space Flight Center in Greenbelt, Md., in a prelaunch interview with Universe Today conducted inside the clean room with GPM before it’s shipment to Japan.
NASA’s next generation Global Precipitation Measurement (GPM) observatory inside the clean room at NASA Goddard Space Flight Center, MD. Technicians at work on final processing during exclusive up-close inspection tour by Universe Today. GPM is slated to launch on February 27, 2014 and will provide global measurements of rain and snow every 3 hours. Credit: Ken Kremer/kenkremer.com
“The GPM satellite was built in house by the dedicated team at NASA’s Goddard Space Flight Center in Maryland,” Azarbarzin told me.
“It’s the largest satellite ever built at Goddard.”
Following the flawless blastoff, the nearly four ton GPM spacecraft separated from the Japanese rocket some 16 minutes later at an altitude of 247 miles (398 kilometers).
10 minutes later both of the spacecrafts life giving solar arrays deployed as planned.
Major components of the GPM Core Observatory labeled, including the GMI, DPR, HGAS, solar panels, and more. Credit: NASA Goddard
“It is incredibly exciting to see this spacecraft launch,” said Azarbarzin, in a NASA statement. He witnessed the launch in Japan.
“This is the moment that the GPM Team has been working toward since 2006.”
“The GPM Core Observatory is the product of a dedicated team at Goddard, JAXA and others worldwide.”
“Soon, as GPM begins to collect precipitation observations, we’ll see these instruments at work providing real-time information for the scientists about the intensification of storms, rainfall in remote areas and so much more.”
The $933 Million observatory is a joint venture between the US and Japanese space agencies, NASA and the Japan Aerospace Exploration Agency (JAXA).
The 3850 kilogram GPM satellite is equipped with two instruments – an advanced, higher resolution dual -frequency precipitation (DPR) radar instrument (Ku and Ka band) built by JAXA in Japan and the GPM microwave imager (GMI) built by Ball Aerospace in the US.
The GPM observatory will replace the aging NASA/JAXA Tropical Rainfall Measuring Mission (TRMM) satellite launched back in 1997 and also jointly developed by NASA and JAXA.
“GPM is the direct follow-up to the currently orbiting TRMM satellite,” Azarbarzin explained to me.
“TRMM is reaching the end of its usable lifetime. After GPM launches we hope it has some overlap with observations from TRMM.”
GPM is vital to continuing the TRMM measurements. It will help provide improved forecasts and advance warning of extreme super storms like Hurricane Sandy and Super Typhoon Haiyan.
“TRMM was only designed to last three years but is still operating today. We hope GPM has a similar long life,” said Azarbarzin.
NASA astronaut Paul Richards (STS-102) discusses GPM at NASA Goddard Space Flight Center on Feb. 27, 2014. Credit: Ken Kremer/kenkremer.com
Stay tuned here for Ken’s continuing GPM reports and on-site coverage at NASA Goddard Space Flight Center in Maryland.
And watch for Ken’s continuing planetary and human spaceflight news about Curiosity, Opportunity, Chang’e-3, SpaceX, Orbital Sciences, LADEE, MAVEN, MOM, Mars, Orion and more.
Visualization of the GPM Core Observatory and Partner Satellites. GPM launched on Feb. 27 from Japan. Credit: NASANASA/JAXA Global Precipitation Measurement (GPM) satellite inside the clean room at NASA Goddard Space Flight Center, MD, undergoes final processing during exclusive up-close inspection tour by Universe Today: Dr. Art Azarbarzin/NASA GPM project manager, Dr. Ken Kremer/Universe Today and Dr. Dalia Kirschbaum/NASA GPM research scientist. Credit: Ken Kremer/kenkremer.com
Visualization of the GPM Core Observatory and Partner Satellites. Credit: NASA
Visualization of the GPM Core Observatory and Partner Satellites. GPM is slated to launch on Feb. 27 from Japan. Credit: NASA
See launch animation, Shinto ceremony, Rocket roll out and more below[/caption]
NASA GODDARD SPACE FLIGHT CENTER, MARYLAND – Blastoff of the powerful and revolutionary new NASA/JAXA rain and snow precipitation measurement satellite atop a Japanese rocket from a tiny offshore island launch pad is now less than 24 hours away on Thursday, Feb. 27, EST (Feb. 28 JST).
The Global Precipitation Measurement (GPM) Core Observatory aimed at improving forecasts of extreme weather and climate change research has been given a green light for launch atop a Mitsubishi Heavy Industries H-IIA rocket from the Tanegashima Space Center on Tanegashima Island off southern Japan.
Roll out of the H-IIA launch vehicle from the Vehicle Assembly Building is scheduled for this evening, Feb. 26 at 11 p.m. EST.
Update: rocket rolled out. Photo below, plus watch streaming NASA TV below.
Following the Launch Readiness Review, mission managers approved the GO for liftoff.
The H-IIA rocket with GPM rolls to its launch pad in Japan! Credit: NASA/Bill Ingalls
Japanese team members also prayed at a Shinto ceremony for blessings for a successful launch at the Ebisu Shrine, the first shrine in a traditional San-ja Mairi, or Three Shrine Pilgrimage on Tuesday, Feb. 25, 2014 – see photo below.
However, the team also set a newly revised launch time of 1:37 p.m. EST (18:37 UTC, and Feb. 28 at 3:37 a.m. JST).
Mission managers adjusted the H-IIA launch time after concerns raised by a collision avoidance analysis between the GPM spacecraft and the International Space Station (ISS).
GPM will fly at an altitude of 253 miles (407 kilometers) above Earth – quite similar to the ISS.
It’s coverage runs over virtually the entire populated globe from 65 N to 65 S latitudes.
NASA plans live coverage of the launch on Feb. 27 beginning at 12 noon EST on NASA Television.
It will be streamed live at: http://www.nasa.gov/nasatv
The $933 Million observatory is a joint venture between the US and Japanese space agencies, NASA and the Japan Aerospace Exploration Agency (JAXA).
NASA’s next generation Global Precipitation Measurement (GPM) observatory inside the clean room at NASA Goddard Space Flight Center, MD. Technicians at work on final processing during exclusive up-close inspection tour by Universe Today. GPM is slated to launch on February 27, 2014 and will provide global measurements of rain and snow every 3 hours. Credit: Ken Kremer/kenkremer.com
GPM has a one-hour launch window. In case of any delays, the team will be required to conduct a thorough new collision avoidance analysis to ensure safety.
Weather forecast is excellent at this time.
Watch this GPM Launch animation:
Video caption: NASA/JAXA GPM Core Observatory Launch Animation
GPM is a next-generation satellite that will provide global, near real time observations of rain and snow from space. Such data is long awaited by climate scientists and weather forecasters.
It will open a new revolutionary era in global weather observing and climate science. Therefore it will have a direct impact on society and people’s daily lives worldwide.
The mission will significantly advance our understanding of Earth’s water and energy cycles and improve forecasting of extreme weather events.
The 3850 kilogram GPM satellite is equipped with two instruments – an advanced, higher resolution dual -frequency precipitation (DPR) radar instrument (Ku and Ka band) built by JAXA in Japan and the GPM microwave imager (GMI) built by Ball Aerospace in the US.
Major components of the GPM Core Observatory labeled, including the GMI, DPR, HGAS, solar panels, and more. Credit: NASA Goddard
“The GPM satellite was built in house at NASA’s Goddard Space Flight Center in Maryland,” Art Azarbarzin, GPM project manager, told Universe Today during my exclusive up-close clean room inspection tour of the huge satellite as final processing was underway.
Researchers will use the GPM measurements to study climate change, freshwater resources, floods and droughts, and hurricane formation and tracking.
“GPM will join a worldwide constellation of current and planned satellites,” Azarbarzin told me during an interview in the Goddard cleanroom beside GPM.
“GPM is the direct follow-up to the currently orbiting TRMM satellite,” Azarbarzin explained.
“TRMM is reaching the end of its usable lifetime. After GPM launches we hope it has some overlap with observations from TRMM.”
“The Global Precipitation Measurement (GPM) observatory will provide high resolution global measurements of rain and snow every 3 hours,” Dalia Kirschbaum, GPM research scientist, told me during an interview at Goddard.
Stay tuned here for Ken’s continuing GPM reports and on-site coverage at NASA Goddard Space Flight Center in Maryland.
And watch for Ken’s continuing planetary and human spaceflight news about Curiosity, Opportunity, Chang’e-3, SpaceX, Orbital Sciences, LADEE, MAVEN, MOM, Mars, Orion and more.
GPM: Three Shrine Pilgrimage Japan Aerospace Exploration Agency (JAXA) team members bow at the Ebisu Shrine, the first shrine in a traditional San-ja Mairi, or Three Shrine Pilgrimage, where the team prays on Tuesday, Feb. 25, 2014 for a successful launch, Tanegashima Island, Japan. Credit: NASA/Bill IngallsNASA/JAXA Global Precipitation Measurement (GPM) satellite inside the clean room at NASA Goddard Space Flight Center, MD, undergoes final processing during exclusive up-close inspection tour by Universe Today: Dr. Art Azarbarzin/NASA GPM project manager, Dr. Ken Kremer/Universe Today and Dr. Dalia Kirschbaum/NASA GPM research scientist. Credit: Ken Kremer/kenkremer.com
We’ve all seen charts showing the relative sizes of planets and moons compared to each other, which are cool to look at but don’t really give a sense of the comparative masses of the various worlds in our Solar System. It’s one thing to say the Earth is four times larger than the Moon, it’s entirely another to realize it’s 87 times more massive!
That’s where this new animation from astrophysicist Rhys Taylor comes in nicely.
You’ve probably heard the saying “everything’s relative”. When you consider our place in the Universe, everything really is relative. I’m recording this halfway up Vancouver Island, in the Pacific Ocean, off the West Coast of Canada. And where I’m standing is about 6,370 kilometers away from the center of the Earth, that way.
From my perspective, the Sun is over there. It’s as large as a dime held at arm’s length. For me it’s really, really far away. In fact, at this exact time it’s further away than any object I you can see with the naked eye.I’m about 150 million kilometers away from the Sun, and so are you.
We’re carving out an elliptical orbit which takes one full year to complete one whole trip around. You, me and the Earth are all located inside our Solar System. Which contains the Sun, 8 planets and a vast collection of ice, rocks and dust. We’re embedded deep within our galaxy, the Milky Way. It’s a big flat disk of stars measuring up to 120,000 light years across.
Our Solar System is located in the middle of this galactic disk. And by the middle, I mean the center of the galaxy is about 27,000 light years that way, and the edge of the galaxy is about the same distance that way.
Our Milky Way is but one galaxy in a larger collection of galaxies known as the Local Group. There are 36 known objects in the local group. Which are mostly dwarf galaxies. However, there’s also the Triangulum Galaxy, the Milky Way, and the Andromeda galaxy… which is by far the largest, most massive object in the Local Group, It’s twice the size and 4 times the mass of the Milky Way.
But where is it?
Milky Way. Image credit: NASA
From me, and you, Andromeda is located just an astronomically distant 2.5 million light years that way. Or would that be just short 2.5 million light-years that away? I’m sure you see where this is going.
The Local Group is embedded within a much larger group known as the Virgo Supercluster, containing at least 100 galaxy groups and clusters. The rough center of the supercluster is in the constellation Virgo. Which as of right now, is that way, about 65 million light years away. Which certainly makes the 2.5 million light years to Andromeda seem like an afternoon jaunt in the family car.
Unsurprisingly, The Virgo Supercluster is a part of a larger structure as well. The Pisces-Cetus Supercluster Complex. This is a vast filament of galactic superclusters measuring about 150 million light years across AND a billion light years long. The middle is just over that way. Right over there.
Andromeda Galaxy. Credit: Fabio Bortoli
One billion light years in length? Well that makes Andromeda seem right around the corner. So where are we? Where are you, and I and the Earth located in the entire Universe? The edge of the observable Universe is about 13.8 billion light years that way. But it’s also 13.8 billion light years that way. And that way, and that way.
And cosmologists think that if you travel in any direction long enough, you’ll return to your starting point, just like how you can travel in any one direction on the surface of the Earth and return right back at your starting point. In other words, the Earth is located at the very, very center of the Universe. Which sounds truly amazing.
What a strange coincidence for you and I to be located right here. Dead center. Smack dab right in the middle of the Universe. Certainly makes us sound important doesn’t it? But considering that every other spot in the Universe is also located at the center of the universe.
You heard me right. Every single spot that you can imagine inside the Universe is also the center of the Universe. That definitely complicates things in our plans for Universal relevance. And all this sure does make Andromeda seem close by….and it’s still just right over there, at the center of the Universe. Oh, and about every spot in the universe being the center of the Universe? Well, we’ll save that one for another episode.
Anyone who’s ever seen a map or a globe easily knows that the surface of our planet is mostly covered by liquid water — about 71%, by most estimates* — and so it’s not surprising that all Earthly life as we know it depends, in some form or another, on water. (Our own bodies are composed of about 55-60% of the stuff.) But how did it get here in the first place? Based on current understanding of how the Solar System formed, primordial Earth couldn’t have developed with its own water supply; this close to the Sun there just wouldn’t have been enough water knocking about. Left to its own devices Earth should be a dry world, yet it’s not (thankfully for us and pretty much everything else living here.) So where did all the wet stuff come from?
As it turns out, Earth’s water probably wasn’t made, it was delivered. Check out the video above from MinuteEarth to learn more.
*71% of Earth’s surface, yes, but actually less total than you might think. Read more.
MinuteEarth (and MinutePhysics) is created by Henry Reich, with Alex Reich, Peter Reich, Emily Elert, and Ever Salazar. Music by Nathaniel Schroeder.
UPDATE March 2, 2014: recent studies support an “alien” origin of Earth’s water from meteorites, but perhaps much earlier in its formation rather than later. Read more from the Harvard Gazette here.
In 1908 a blazing white line cut across the sky before exploding a few miles above the ground with a force one thousand times stronger than the nuclear blast that leveled Hiroshima, Japan.
The resulting shock wave felled trees across more than 800 square miles in the remote forests of Tunguska, Siberia.
For over 100 years, the exact origins of the Tunguska event have remained a mystery. Without any fragments or impact craters to study, astronomers have been left in the dark. That’s not to say that all kinds of extraordinary causes haven’t been invoked to explain the event. Various people have thought of everything from Earth colliding with a small black hole to the crash of a UFO.
Russian researchers claim they may finally have evidence that will dislodge all conspiracy theories, but that “may” is huge. A team of four believes they have recovered fragments of the object — the so-called Tunguska meteorite — and even think they are Martian in origin. The research, however, is being called into question.
In a detective-like manner, the team surveyed 100 years’ worth of research. The researchers read eyewitness reports and analyzed aerial photos of the location. They performed a systematic survey of the central region in the felled forest and analyzed exotic rocks and penetration funnels.
A schematic of the central region in the felled forest due to the Tunguska event. Image Credit: Anfinogenov et al.
Previously, numerous expeditions failed to recover any fragments that could be attributed conclusively to the long-sought Tunguska meteorite. But then Andrei Zlobin, of the Russian Academy of Sciences’ Vernadsky State Geological Museum, discovered three stones with possible traces of melting. He published the results in April 2013.
Zlobin’s discovery paper was received with skepticism and Universe Today covered the news immediately. A curious question arose quickly: why did it take so long for Zlobin to analyze his samples? The expedition took place in 1988, but it took 20 years before the three Tunguska candidates were nominated and another five years before Zlobin finished the paper.
By Zlobin’s admission, his discovery paper was only a preliminary study. He claimed he didn’t carry out a detailed chemical analysis of the rocks, which is necessary in order to reveal their true nature. Most field experts quickly dismissed the paper, feeling there was more work to be done before Zlobin could truly know if these rocks were fragments from the Tunguska meteor.
Today, new research is moving forward with an analysis of the rocks originally discovered by Zlobin. But an interesting new addition to the collection is a rock called “John’s Stone” — a large boulder discovered in July, 1972. While it’s mostly a dark gray now it was much lighter at the time of its discovery. “John’s Stone has an almond-like shape with one broken side,” lead author Dr. Yana Anfinogenov told Universe Today.
Now the skeptical reader might be asking the same question as before: why is there such a large time-lapse between the discovery of John’s Stone and the analysis presented here? (It’s interesting to note that while this elusive rock has been reviewed in the literature for over 40 years, this is the first time it has appeared in an English paper). Anfinogenov claimed that new data (especially concerning Martian geology) allowed for a much better analysis today than it did in recent years.
Photos (1972) of John’s Stone and related findings. Image Credit: Anfinovenov et al.
“The ground near John’s Stone presents undeniable impact signs suggesting that the boulder hit the ground with a catastrophic speed,” Anfinogenov told Universe Today. It left a deep trace in the permafrost which allowed researchers to note its trajectory and landing velocity coincides with that of the incoming Tunguska meteorite.
John’s Stone also contains shear-fractured splinter fragments with glossy coatings, indicating the strong effect of heat generated when it entered our atmosphere. The research team attempted to reproduce those glossy coatings found on the splinters by heating another fragment of John’s Stone to 500 degrees Celsius. The experiment was not successful as the fragment disintegrated in high heat.
“The authors do not present a strong case that the boulder known as John’s Stone was involved in the Tunguska event, or that it originated from Mars,” said Dr. Phil Bland, a meteorite expert at Curtin University in Perth, Australia.
They claim the mineral structure and chemical composition of the rocks — a quartz-sandstone with grain sizes of 0.5 to 1.5 cm and rich in silica — match rocks found on Mars. But their paper lacks any microanalysis of the samples, or isotopic study.
While there is a strong case that an impact on Mars could easily eject rock fragments that would then hit the Earth, something doesn’t match up. “The physics of ejecting material from Mars into interplanetary space argues for fragments with diameters of one to two meters, not the 20 to 30 meter range that would be required for Tunguska,” Bland told Universe Today.
It seems as though planetary geologists will require a much stronger case than this to be truly convinced John’s Stone is the Tunguska meteorite, let alone from Mars.
The paper is currently under peer-review but is available for download here.
