The early days of the Solar System are hard to piece together from our vantage point, billions of years after it happened. Now a team of scientists have found a tiny chunk of an ancient comet inside an ancient meteorite. They say it sheds light on the early days of the Solar System when planets were still forming.Continue reading “Astronomers Find a Chunk of a Comet Inside a Meteorite”
An ice shelf in Antarctica is about to give birth to a baby. This baby is a giant, spawned by growing cracks in the Brunt Ice Shelf. It’s not clear what this’ll mean to the scientific infrastructure in the area, and to the human presence, which were both established in the 1950s.Continue reading “Antarctica is About to Unleash an Iceberg Twice the Size of New York City”
One of the benefits of the Space Age is the way it has allowed human beings to see Earth in all of its complexity and splendor. In addition, it has allowed us to conduct studies of Earth’s surface and atmosphere from orbit, which helps us to see the impact we have on our the planet. It is with this purpose in mind that NASA’s Earth Observation Program has been monitoring the Arctic and Antarctic for many years.
For instance, Operation IceBridge has spent much of the past decade monitoring the Antarctic ice sheet for signs of cracks and flows. The purpose of this is to determine how and at what rate the ice sheet is changing due to Climate Change. Recently, NASA crews conducted a flight over the southern Antarctic Peninsula as part of Operation IceBridge ninth year, which resulted in some stunning pictures of the icy landscape.
The flight took place on November 4th, 2017, as part of IceBridge’s “Endurance West” mission to study sea ice. The path they chose follows the ground track of NASA’s Ice, Cloud, and land Elevation Satellite-2 (ICESat-2), an ice-mapping satellite that is scheduled for launch in late 2018. This path began at the northern tip of the Antarctic Peninsula and then moved southward across the Weddell Sea.
The images the crew took aboard their P3 research plane were captured by a Digital Mapping System, a downward-pointing camera that collects thousands of high-resolution photographs during a single flight. While traveling over the southern Antarctic Peninsula, they imaged a landscape that resembled rapids, where the motion of rivers becomes amplified as the water flows through steeper, narrower terrain.
In a similar fashion, as ice flows through narrower canyons and down steeper bedrock, more fractures appear at the surface. But of course, the rate at which this takes place is much slower, which can make discerning movement in the ice sheet rather difficult. The first image (shown above) shows ice flowing into the southern part of the George VI ice shelf, which is located in Palmer Land south of the Seward Mountains.
In this location, cracks are likely to be a regular feature that form as the ice flows over the bedrock. However, since the ice flow is relatively slow (even on the steeper part of the bedrock), the surface cracks are not as dramatic as in other regions. For example, the second image (shown below), which shows a heavily crevassed glacier that measures about 21 km (13 mi) long and 11 km (7 mi) wide.
The glacier appears to be flowing west from the Dyer Plateau to George VI Sound while the north side merges with the Meiklejohn Glacier. The third image (bottom) shows a heavily crevassed glacier north of Creswick Peaks that also flows west into George VI Sound. In short, the pictures confirm that ice on the southern end of the Antarctic Peninsula is flowing towards the ocean.
The purpose of IceBridge, which has been conducting regular measurements in the Antarctic Peninsula since 2009, has been to study just how fast and to what extent Climate Change has been impacting the region. While ice sheet loss is a well-documented phenomenon, scientists have known for some time that the most dramatic losses in Antarctica occur along its western side.
In addition, research has shown that the southern part of the peninsula is particularly vulnerable, as the glaciers and ice shelves there have become destabilized and are slowly feeding into the sea. And unlike sea ice, the land ice in this region has the potential to raise sea levels around the world. As Michael Studinger, the project manager for IceBridge, describes the operation:
“IceBridge exists because we need to understand how much ice the Greenland and Antarctic ice sheets will contribute to sea level rise over the next couple of decades. In order to do this, we need to measure how much the ice surface elevation is changing from year to year.”
Knowing how significant the impact of Climate Change will be is the first step in developing countermeasures. It also serves as a stark reminder that the problem exists, and that solutions need to be found before it is too late.
Further Reading: NASA Earth Observatory
Beneath the Antarctic ice sheet, there lies a continent that is covered by rivers and lakes, the largest of which is the size of Lake Erie. Over the course of a regular year, the ice sheet melts and refreezes, causing the lakes and rivers to periodically fill and drain rapidly from the melt water. This process makes it easier for Antarctica’s frozen surface to slide around, and to rise and fall in some places by as much as 6 meters (20 feet).
According to a new study led by researchers from NASA’s Jet Propulsion Laboratory, there may be a mantle plume beneath the area known as Marie Byrd Land. The presence of this geothermal heat source could explain some of the melting that takes place beneath the sheet and why it is unstable today. It could also help explain how the sheet collapsed rapidly in the past during previous periods of climate change.
The study, titled “Influence of a West Antarctic mantle plume on ice sheet basal conditions“, recently appeared in the Journal of Geophysical Research: Solid Earth. The research team was led by Helene Seroussi of the Jet Propulsion Laboratory, with support from researchers from the Department of Earth and Planetary Sciences at Washington University and the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research in Germany.
The motion of Antarctica’s ice sheet over time has always been a source of interest to Earth scientists. By measuring the rate at which the ice sheet rises and falls, scientists are able to estimate where and how much water is melting at the base. It is because of these measurements that scientists first began to speculate about the presence of heat sources beneath Antarctica’s frozen surface.
The proposal that a mantle plume exists under Marie Byrd Land was first made 30 years ago by Wesley E. LeMasurier, a scientist from the University of Colorado Denver. According to the research he conducted, this constituted a possible explanation for regional volcanic activity and a topographic dome feature. But it was only more recently that seismic imaging surveys offered supporting evidence for this mantle plume.
However, direct measurements of the region beneath Marie Byrd Land is not currently possible. Hence why Seroussi and Erik Ivins of the JPL relied on the Ice Sheet System Model (ISSM) to confirm the existence of the plume. This model is essentially a numerical depiction of the physics of the ice sheet, which was developed by scientists at the JPL and the University of California, Irvine.
To ensure that the model was realistic, Seroussi and her team drew on observations of changes in altitude of the ice sheet made over the course of many years. These were conducted by NASA’s Ice, Clouds, and Land Elevation Satellite (ICESat) and their airborne Operation IceBridge campaign. These missions have been measuring the Antarctic ice sheet for years, which have led tot he creation of very accurate three-dimensional elevation maps.
Seroussi also enhanced the ISSM to include natural sources of heating and heat transport that result in freezing, melting, liquid water, friction, and other processes. This combined data placed powerful constrains on the allowable melt rates in Antarctica, and allowed the team to run dozens of simulations and test a wide range of possible locations for the mantle plume.
What they found was that the heat flux caused by the mantle plume would not exceed more than 150 milliwatts per square meter. By comparison, regions where there is no volcanic activity typically experience a feat flux of between 40 and 60 milliwatts, whereas geothermal hotspots – like the one under Yellowstone National Park – experience an average of about 200 milliwatts per square meter.
Where they conducted simulations that exceeded 150 millwatts per square meter, the melt rate was too high compared to the space-based data. Except in one location, which was an area inland of the Ross Sea, which is known to experience intense flows of water. This region required a heat flow of at least 150 to 180 milliwatts per square meter to align with its observed melt rates.
In this region, seismic imaging has also shown that heating might reach the ice sheet through a rift in the Earth’s mantle. This too is consistent with a mantle plume, which are thought to be narrow streams of hot magma rising through the Earth’s mantle and spreading out under the crust. This viscous magma then balloons under the crust and causes it to bulge upward.
Where ice lies over top of the plume, this process transfers heat into the ice sheet, triggering significant melting and runoff. In the end, Seroussi and her colleagues provide compelling evidence – based on a combination of surface and seismic data – for a surface plume beneath the ice sheet of West Antarctica. They also estimate that this mantle plume formed roughly 50 to 110 million years ago, long before the West Antarctic ice sheet came into existence.
Roughly 11,000 years ago, when the last ice age ended, the ice sheet experienced a period of rapid, sustained ice loss. As global weather patterns and rising sea levels began to change, warm water was pushed closer to the ice sheet. Seroussi and Irvins study suggests that the mantle plume could be facilitating this kind of rapid loss today, much as it did during the last onset of an inter-glacial period.
Understanding the sources of ice sheet loss under West Antarctica is important as far as estimating the rate at which ice may be lost there, which is essentially to predicting the effects of climate change. Given that Earth is once again going through global temperature changes – this time, due to human activity – it is essential to creating accurate climate models that will let us know how rapidly polar ice will melt and sea levels will rise.
It also informs our understanding of how our planet’s history and climate shifts are linked, and what effect these had on its geological evolution.
KENNEDY SPACE CENTER, FL – Barely a year after NASA’s OSIRIS-REx robotic asteroid sampler launched on a trailblazing mission to snatch a soil sample from a pristine asteroid and return it to Earth for research analysis, the probe is speeding back home for a swift slingshot around our home planet on Friday Sept. 22 to gain a gravity assist speed boost required to complete its journey to the carbon rich asteroid Bennu and back.
As it swings by Earth NASA’s first ever asteroid sample return mission, OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer), will pass only 11,000 miles (17,000 kilometers) above Earth just before 12:52 p.m. EDT on Friday.
And NASA is asking the public to try and ‘Catch It If You Can’ – by waving hello and/or taking snapshots during and after the probes high speed flyby.
Plus you can watch NASA Facebook Live event at Noon Friday: https://www.facebook.com/NASAGoddard/
OSIRIS-REx will be approaching Earth at a velocity of about 19,000 mph on Friday as it begins flying over Australia during the Earth Gravity Assist (EGA) maneuver.
Since blastoff from the Florida Space Coast on Sept. 8, 2016 the probe has already racked up almost 600 million miles on its round trip journey from Earth and back to set up Friday’s critical gravity assist maneuver to Bennu and back.
As OSIRIS-REx continues along its flight path the spacecraft will reach its closest point to Earth over Antarctica, just south of Cape Horn, Chile. It will gain a velocity boost of about 8400 mph.
The spacecraft will also conduct a post flyby science campaign by collecting images and science observations of Earth and the Moon four hours after closest approach to calibrate its five science instruments.
The allure of Bennu is that it is a carbon rich asteroid – thus OSIRIS-REx could potentially bring back samples infused with the organic chemicals like amino acids that are the building blocks of life as we know it.
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation,” OSIRIS-Rex Principal Investigator Dante Lauretta told Universe Today in a prelaunch interview with the spacecraft in the cleanroom at NASA’s Kennedy Space Center.
The do or die gravity assist plunge is absolutely essential to set OSIRIS-REx on course to match the asteroid’s path and speed when it reaches the vicinity of asteroid Bennu a year from now in October 2018.
“The Earth Gravity Assist is a clever way to move the spacecraft onto Bennu’s orbital plane using Earth’s own gravity instead of expending fuel,” says Lauretta, of the University of Arizona, Tucson.
Bennu’s orbit around the Sun is tilted at a six-degree inclination with respect to Earth’s orbital plane.
The asteroid is 1,614-foot (500 m) in diameter and crosses Earth’s orbit around the sun every six years.
Numerous NASA spacecraft – including NASA’s just completed Cassini mission to Saturn – utilize gravity assists around a variety of celestial bodies to gain speed and change course to save vast amounts of propellant and time in order to accomplish science missions and visit additional target objects that would otherwise be impossible.
The flyby will be a nail-biting time for NASA and the science team because right afterwards the refrigerator sized probe will be out of contact with engineers – unable to receive telemetry for about an hour.
“For about an hour, NASA will be out of contact with the spacecraft as it passes over Antarctica,” said Mike Moreau, the flight dynamics system lead at Goddard, in a statement.
“OSIRIS-REx uses the Deep Space Network to communicate with Earth, and the spacecraft will be too low relative to the southern horizon to be in view with either the Deep Space tracking station at Canberra, Australia, or Goldstone, California.”
NASA says the team will regain communication with OSIRIS-REx roughly 50 minutes after closest approach over Antarctica at about 1:40 p.m. EDT.
The post flyby science campaign is set to begin at 4:52 p.m. EDT, Friday, Sept. 22.
The OSIRIS-Rex spacecraft originally departed Earth atop a United Launch Alliance Atlas V rocket under crystal clear skies on September 8, 2016 at 7:05 p.m. EDT from Space Launch Complex 41 at Cape Canaveral Air Force Station, Florida.
Everything with the launch went exactly according to plan for the daring mission boldly seeking to gather rocks and soil from carbon rich Bennu.
OSIRIS-Rex is equipped with an ingenious robotic arm named TAGSAM designed to collect at least a 60-gram (2.1-ounce) sample and bring it back to Earth in 2023 for study by scientists using the world’s most advanced research instruments.
“The primary objective of the OSIRIS-Rex mission is to bring back pristine material from the surface of the carbonaceous asteroid Bennu,” OSIRIS-Rex Principal Investigator Dante Lauretta told me in the prelaunch interview in the KSC cleanroom with the spacecraft as the probe was undergoing final launch preparations.
“We are interested in that material because it is a time capsule from the earliest stages of solar system formation.”
“It records the very first material that formed from the earliest stages of solar system formation. And we are really interested in the evolution of carbon during that phase. Particularly the key prebiotic molecules like amino acids, nucleic acids, phosphates and sugars that build up. These are basically the biomolecules for all of life.”
NASA and the mission team is also inviting the public to get engaged by participating in the Wave to OSIRIS-REx social media campaign.
“Individuals and groups from anywhere in the world are encouraged to take photos of themselves waving to OSIRIS-REx, share them using the hashtag #HelloOSIRISREx and tag the mission account in their posts on Twitter (@OSIRISREx) or Instagram (@OSIRIS_REx).
Participants may begin taking and sharing photos at any time—or wait until the OSIRIS-REx spacecraft makes its closest approach to Earth at 12:52p.m. EDT on Friday, Sept. 22.”
The probe’s flight path during the flyby will pass through the ring of numerous satellites orbiting in geosynchronous orbit, but none are expected to be within close range.
Watch for Ken’s continuing onsite NASA mission and launch reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
For several months, scientists have been keeping an eye on a piece of Antarctica’s Larsen C ice shelf, waiting for the inevitable. And now it has happened.
Sometime between July 10 and July 12, 2017 a trillion ton iceberg split off, “changing the outline of the Antarctic Peninsula forever,” said one scientist.
The new iceberg is now called A68, and at 2,240 square miles (5,800 square km) it is one of the biggest ever recorded, about the size of Delaware in the US, or twice the size of Luxembourg.
A fissure on the ice shelf first appeared several years ago, but seemed relatively stable until January 2016, when it began to lengthen. In January 2017 alone, the crack grew by 20 km, reaching a total length of about 175 km.
The calving of the iceberg was confirmed by the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite and was reported this morning by Project MIDAS, an Antarctic research project based in the UK.
The MODIS instrument on NASA’s Aqua satellite also confirmed the complete separation of the iceberg.
— NASA Goddard (@NASAGoddard) July 12, 2017
Larsen C is a floating platform of glacial ice on the east side of the Antarctic Peninsula, is the fourth largest ice shelf ringing Earth’s southernmost continent. With the break-off of this iceberg, the Larsen C shelf area has shrunk by approximately 10 percent.
Some scientists say the Larsen C rift and iceberg calving is not a warning of imminent sea level rise, and linking climate change to this specific event is complicated. Adrian Luckman, Professor of Glaciology and Remote Sensing from Swansea University wrote a detailed explanation of this for The Conversation.
David Vaughan, glaciologist and Director of Science at British Antarctic Survey (BAS), said, “Larsen C itself might be a result of climate change, but, in other ice shelves we see cracks forming, which we don’t believe have any connection to climate change. For instance on the Brunt Ice Shelf where BAS has its Halley Station, there those cracks are a very different kind which we don’t believe have any connection to climate change.”
While Vaughan said they see no obvious signal that climate warming is causing the whole of Antarctica to break up, he added that there is little doubt that climate change is causing ice shelves to disappear in some parts of Antarctica at the moment.
— ESA EarthObservation (@ESA_EO) July 12, 2017
“Around the Antarctic Peninsula, where we saw several decades of warming through the latter half of the 20th century, we have seen these ice shelves collapsing and ice loss increasing,” he said. “There are other parts of the Antarctica that which are losing ice to the oceans but those are affected less by atmospheric warming and more by ocean change.
Scientists said the loss of such a large piece is of interest because ice shelves along the peninsula play an important role in ‘buttressing’ glaciers that feed ice seaward, effectively slowing their flow.
“The interesting thing is what happens next, how the remaining ice shelf responds,” said Kelly Brunt, a glaciologist with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland in College Park. “Will the ice shelf weaken? Or possibly collapse, like its neighbors Larsen A and B? Will the glaciers behind the ice shelf accelerate and have a direct contribution to sea level rise? Or is this just a normal calving event?”
The U.S. National Ice Center will monitor the trajectory of the new iceberg, but they don’t expect it to travel far very fast, and it shouldn’t cause any immediate problems for navigation of ships.
Located along the east coast of the Antarctic Peninsula is the Larsen Ice Shelf. Named after the Norwegian Captain who explored the ice front back in 1893, this ice shelf has been monitored for decades due to its close connection with rising global temperatures. Essentially, since the 1990s, the shelf has been breaking apart, causing collapses of considerable intensity.
According to the British Antarctic Survey (BAS), the section of the ice sheet known as the Larsen C Ice Shelf could be experiencing a collapse of its own soon enough. Based on video footage and satellite evidence of the sizeable rift (which is 457 m or 15oo ft across) in the shelf, it is believed that an ice berg that is roughly 5,000 km² (1930.5 mi²) in size could be breaking off and calving into the ocean in the near future.
An ice shelf is essentially a floating extension of a land-based glacier. In this case, the Larsen Ice Shelf is seaborne section of the larger Larsen Glacier, which flows southeast past Mount Larsen and enters the Ross Sea just south of Victoria Land. These shelves often act as buttresses, holding back glaciers that flow down to the coast, thus preventing them from entering the ocean and contributing to rising sea levels.
In the past twenty-two years, the Larsen A and B ice shelves (which were situated further north along the Antarctic Peninsula) both collapsed into the sea. This resulted in the dramatic acceleration of glaciers behind them, as larger volumes of ice were able to flow down the coast and drop into the ocean. While Larsen C appeared to still be stable, in November of 2016, NASA noted the presence of a large crack in its surface.
This crack was about 110 kilometers (68 mi) long and was more than 91 m (299 ft) wide, reaching a depth of about 500 m (1,600 ft). By December, the rift had extended another 21 km (13 mi), which raised concerns about calving. In February of 2017, satellite observations of the shelf noted that the crack appeared to have grown further, which confirmed what researches from the MIDAS project had previously reported.
This UK-based Antarctic research project – which is based at Swansea University and Aberystwyth University in Wales and supported by the BAS and various international partners – is dedicated to monitoring the Larsen C ice shelf in Antarctica. Through a combination of field work, satellite observations, and computer simulations, they have catalogued how recent warming trends has caused seasonal melts of the ice shelf and affected its structure.
And in recent years, they have been monitoring the large crack, which has been fast-moving, and noted the appearance of several elongations. It was during the current Antarctic field season that members of the project filmed what the crack looked like from the air. In previous surveys, the glaciology research team has conducted research on the ice shelf using seismic techniques to survey the seafloor beneath it.
However, this past season, they did not set up on the ice shelf itself for fear of a calving event. Instead, they made a series of trips to and from the UK’s Rothera Research Station aboard twin otter aircraft. During an outing to retrieve some of their science equipment, the crew noted how the crack looked from above and started filming. As you can see from the footage, the rift is very wide and extremely long.
What’s more, the team estimates that if an iceberg from this shelf breaks off and falls into the ocean, it will likely be over three times the size of cities like London or New York City. And while this sort of thing is common with glaciers, the collapse of a large section of Larsen C could speed the flow of the Larsen Glacier towards the Antarctic Ocean.
As Dr Paul Holland, an ice and ocean modeller at the British Antarctic Survey, said in a recent press release:
“Iceberg calving is a normal part of the glacier life cycle, and there is every chance that Larsen C will remain stable and this ice will regrow. However, it is also possible that this iceberg calving will leave Larsen C in an unstable configuration. If that happens, further iceberg calving could cause a retreat of Larsen C. We won’t be able to tell whether Larsen C is unstable until the iceberg has calved and we are able to understand the behavior of the remaining ice. The stability of ice shelves is important because they resist the flow of the grounded ice inland. After the collapse of Larsen B, its tributary glaciers accelerated, contributing to sea-level rise.”
One of the greatest concerns about climate change is the feedback mechanisms it creates. In addition to increased warming trends caused by rising levels of CO² in the atmosphere, the melting of glaciers and the breakup of ice shelves can have a pronounced effect on sea levels. In the end, the depletion of glaciers in Antarctica could have dramatic consequences for the rest of the planet.
Further Reading: British Antarctic Survey
Buzz Aldrin – the second man to walk on the Moon – is recovering nicely today in a New Zealand hospital after an emergency medical evacuation cut short his record setting Antarctic expedition as the oldest man to reach the South Pole – which Team Buzz lightheartly noted would make him “insufferable”!
“He’s recovering well in NZ [New Zealand],” Team Buzz said in an official statement about his evacuation from the South Pole.
Apollo 11 moonwalker Buzz Aldrin, who followed Neil Armstrong in descending to the lunar surface in 1969 on America’s first Moon landing mission, had to be suddenly flown out of the Admunsen-Scott Science Station late last week per doctors orders after suffering from shortness of breath and lung congestion during his all too brief foray to the bottom of the world.
He was flown to a hospital in Christchurch, New Zealand for emergency medical treatment on Dec. 1.
Upon learning from the National Science Foundation (NSF) that Aldrin “now holds the record as the oldest person to reach the South Pole at the age of 86,” his Mission Director Christina Korp jokingly said: ‘He’ll be insufferable now.”
“Buzz Aldrin is resting in hospital in Christchurch, New Zealand. He still has some congestion in his lungs so has been advised not to take the long flight home to the States and to rest in New Zealand until it clears up,” Team Buzz said in an official statement on Dec. 3.
Buzz had been at the South Pole for only a few hours when he took ill, apparently from low oxygen levels and symptoms of altitude sickness.
“I’m extremely grateful to the National Science Foundation (NSF) for their swift response and help in evacuating me from the Admunsen-Scott Science Station to McMurdo Station and on to New Zealand. I had been having a great time with the group at White Desert’s camp before we ventured further south. I really enjoyed the time I spent talking with the Science Station’s staff too,” said Aldrin from his hospital room in a statement.
Prior to the planned Antarctic journey, his doctors had cleared him to take the long trip – which he views as “the capstone of his personal exploration achievements”.
Buzz’s goal in visiting the South Pole was to see “what life could be like on Mars” – which he has been avidly advocating as the next goal for a daring human spaceflight journey to deep space.
“His primary interest in coming to Antarctica was to experience and study conditions akin to Mars that are more similar there than any other place on earth,” Team Buzz elaborated.
He had hoped to speak more to the resident scientists about their research but it was all cut short by his sudden illness.
“I started to feel a bit short of breath so the staff decided to check my vitals. After some examination they noticed congestion in my lungs and that my oxygen levels were low which indicated symptoms of altitude sickness. This prompted them to get me out on the next flight to McMurdo and once I was at sea level I began to feel much better. I didn’t get as much time to spend with the scientists as I would have liked to discuss the research they’re doing in relation to Mars. My visit was cut short and I had to leave after a couple of hours. I really enjoyed my short time in Antarctica and seeing what life could be like on Mars,” Aldrin explained.
Buzz also thanked everyone who sent him well wishes.
“Finally, thanks to everyone from around the world for their well wishes and support. I’m being very well looked after in Christchurch. I’m looking forward to getting home soon to spend Christmas with my family and to continue my quest for Cycling Pathways and a permanent settlement on Mars. You ain’t seen nothing yet!”, concluded Aldrin.
I recently met Buzz Aldrin at the Kennedy Space Center Visitor Complex in Florida, as part of the Grand Opening of the new ‘Destination Mars’ attraction.
Destination Mars is a holographic exhibit at the Kennedy Space Center visitor complex in Florida. Be sure to catch it soon because the limited time run end on New Year’s Day 2017.
The new ‘Destination Mars’ limited engagement exhibit magically transports you to the surface of the Red Planet via Microsoft HoloLens technology.
It literally allows you to ‘Walk on Mars’ using real imagery taken by NASA’s Mars Curiosity rover and explore the alien terrain, just like real life scientists on a geology research expedition – with Buzz Aldrin as your guide.
Here’s my Q & A with moonwalker Buzz Aldrin speaking to Universe Today at Destination Mars:
Video Caption: Buzz Aldrin at ‘Destination Mars’ Grand Opening at KSCVC. Apollo 11 moonwalker Buzz Aldrin talks to Universe Today/Ken Kremer during Q&A at ‘Destination Mars’ Holographic Exhibit Grand Opening ceremony at Kennedy Space Center Visitor Complex (KSCVC) in Florida on 9/18/16. Credit: Ken Kremer/kenkremer.com
And Buzz seemed quite healthy for the very recent Grand Opening of the new ‘Heroes and Legends’ exhibit on Nov. 11 at the Kennedy Space Center Visitor Complex.
Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.
Learn more about ULA Delta 4 launch on Dec 7, GOES-R weather satellite, Heroes and Legends at KSCVC, OSIRIS-REx, InSight Mars lander, ULA, SpaceX and Orbital ATK missions, Juno at Jupiter, SpaceX AMOS-6 & CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:
Dec 5-7: “ULA Delta 4 Dec 7 launch, GOES-R weather satellite launch, OSIRIS-Rex, SpaceX and Orbital ATK missions to the ISS, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
When you hear the word desert, what comes to mind? Chances are, you’d think of sun, sand, and very little in the way of rain. Perhaps cacti, vultures, mesas, and scorpions come to mind as well, or possibly camels and oases? But in truth, deserts come in all shapes and sizes, and vary considerably from one part of the world to the next.
Like all of Earth’s climates, it all comes down to some basic characteristics that they share – which in this case, involves being barren, dry, and hostile to life. For this reason, you might be surprised to learn that the largest desert in the world is actually in Antarctica. How’s that for a curveball?
To break it down, a desert is a region that is simply very dry because its receives little to no water. To be considered a desert, an area must receive than 250 millimeters of annual precipitation. But precipitation can take the form of rain, snow, mist or fog – literally any form of water being transferred from the atmosphere to the earth.
Deserts can also be described as areas where more water is lost by evaporation than falls as precipitation. This certainly applies in regions that are subject to “desertification”, where increasing temperatures (i.e. climate change) result in river beds drying up, precipitation patterns changing, and vegetation dying off.
Deserts are often some of the hottest and most inhospitable places on Earth, as exemplified by the Sahara Desert in Africa, the Gobi desert in northern China and Mongolia, and Death Valley in California. But they can also be cold, windswept landscapes where little to no snow ever falls – like in the Antarctic and Arctic.
So in the end, being hot has little to do with it. In fact, it would be more accurate to say that deserts are characterized by little to no moisture and extremes in temperature. All told, deserts make up one-third of the surface of the Earth. But most of that is found in the polar regions.
In terms of sheer size, the Antarctic Desert is the largest desert on Earth, measuring a total of 13.8 million square kilometers. Antarctica is the coldest, windiest, and most isolated continent on Earth, and is considered a desert because its annual precipitation can be less than 51 mm in the interior.
It’s covered by a permanent ice sheet that contains 90% of the Earth’s fresh water. Only 2% of the continent isn’t covered by ice, and this land is strictly along the coasts, where all the life that is associated with the land mass (i.e. penguins, seals and various species of birds) reside. The other 98% of Antarctica is covered by ice which averages 1.6 km in thickness.
There are no permanent human residents, but anywhere from 1,000 to 5,000 researchers inhabit the research stations scattered across the continent – the largest being McMurdo Station, located on the tip of Ross Island. Beyond a limited range of mammals, only certain cold-adapted species of mites, algaes, and tundra vegetation can survive there.
Despite having very little precipitation, Antarctica still experiences massive windstorms. Much like sandstorms in the desert, the high winds pick up snow and turn into blizzards. These storms can reach speeds of up to 320 km an hour (200 mph) and are one of the reasons the continent is so cold.
In fact, the coldest temperature ever recorded was taken at the Soviet Vostok Station on the Antarctic Plateau. Using ground-based measurements, the temperature reached a historic low of -89.2°C (-129°F) on July 21st, 1983. Analysis of satellite data indicated a probable temperature of around -93.2 °C (-135.8 °F; 180.0 K), also in Antarctica, on August 10th, 2010. However, this reading was not confirmed.
Interestingly, the second-largest desert in the world is also notoriously cold – The Arctic Desert. Located above 75 degrees north latitude, the Arctic Desert covers a total area of about 13.7 million square km (5.29 million square mi). Here, the total amount of precipitation is below 250mm (10 inches), which is predominantly in the form of snow.
The average temperature in the Arctic Desert is -20 °C, reaching as low as -50 °C in the winter. But perhaps the most interesting aspect of the Arctic Desert is its sunshine patterns. During the summer months, the sun doesn’t set for a period of 60 days. These are then followed in the winter by a period of prolonged darkness.
The third largest desert in the world is the more familiar Sahara, with a total size of 9.4 million square km. The average annual rainfall ranges from very low (in the northern and southern fringes of the desert) to nearly non-existent over the central and the eastern part. All told, most of the Saraha receives less than 20 mm (0.79 in).
However, in northern fringe of the desert, low pressure systems from the Mediterranean Sea result in an annual rainfall of between 100 to 250 mm (3.93 – 9.84 in). The southern fringe of the desert – which extends from coastal Mauritania to the Sudan and Eritrea – receives the same amount of rainfall from the south. The central core of the desert, which is extremely arid, experiences an annual rainfall of less than 1 mm (0.04 in).
Temperatures are also quite intense in the Sahara, and can rise to more than 50 °C. Interestingly, this is not the hottest desert on the planet though. The hottest temperature ever recorded on Earth was 70.7 °C (159 °F), which was taken in the Lut Desert of Iran. These measurements were part of a global temperature survey conducted by scientists at NASA’s Earth Observatory during the summers of 2003 to 2009.
In short, deserts are not just sand dunes and places where you might come across Bedouins and Berbers, or a place you have to drive through to get to Napa Valley. They are common to every continent of the world, and can take the form of sandy deserts or icy deserts. In the end, the defining characteristic is their pronounced lack of moisture.
In that respect, the polar regions are the largest deserts in the world, with Antarctica narrowly beating out the Arctic for first place. And going by this definition – i.e. cold, arid, and with little to no precipitation – we’re sure to find some particularly big deserts elsewhere in Solar System. After all, what is Mars if not one big, cold, arid, and extremely dry climate?
We have written many articles about the Earth for Universe Today. Here is What Percent of the Earth’s Land Surface is Desert?, What is the Driest Place on Earth?, What is the Hottest Place on Earth?, What is the Earths’ Average Temperature?
We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.
In the category of why-didn’t-I think-of-that ideas, Dr. Geoffrey Evatt and colleagues from the University of Manchester struck upon a brilliant hypothesis: that a layer of iron meteories might lurk just below the surface of the Antarctic ice. He’s the lead author of a recent paper on the topic published in the open-access journal, Nature Communications.
Remote Antarctica makes one of the best meteorite collecting regions on the planet. Space rocks have been accumulating there for millennia preserved in the continent’s cold, desert-like climate. While you might think it’s a long and expensive way to go to hunt for meteorites, it’s still a lot cheaper than a sample return mission to the asteroid belt. Meteorites fall and become embedded in ice sheets within the continent’s interior. As that ice flows outward toward the Antarctic coastlines, it pushes up against the Transantarctic Mountains, where powerful, dry winds ablate away the ice and expose their otherworldly cargo.
Layer after layer, century after century, the ice gets stripped away, leaving rich “meteorite stranding zones” where hundreds of space rocks can be found within an area the size of a soccer field. Since most meteorites arrive on Earth coated in a black or brown fusion crust from their searing fall through the atmosphere, they contrast well against the white glare of snow and ice. Scientists liken it to a conveyor belt that’s been operating for the past couple million years.
Scientists form snowmobile posses and buzz around the ice fields picking them up like candy eggs on Easter morning. OK, it’s not that easy. There’s much planning and prep followed by days and nights of camping in bitter cold with high winds tearing at your tent. Expeditions take place from October through early January when the Sun never sets.
The U.S. under ANSMET (Antarctic Search for Meteorites, a Case Western Reserve University project funded by NASA), China, Japan and other nations run programs to hunt and collect the precious from the earliest days of the Solar System before they find their way to the ocean or are turned to dust by the very winds that revealed them in the first place. Since systematic collecting began in 1976, some 34,927 meteorites have been recovered from Antarctica as of December 2015.
Meteorites come in three basic types: those made primarily of rock; stony-irons comprised of a mixture of iron and rock; and iron-rich. Since collection programs have been underway, Antarctic researchers have uncovered lots of stony meteorites, but meteorites either partly or wholly made of metal are scarce compared to what’s found in other collecting sites around the world, notably the deserts of Africa and Oman. What gives?
Dr. Evatt and colleagues had a hunch and performed a simple experiment to arrive at their hypothesis. They froze two meteorites of similar size and shape — a specimen of the Russian Sikhote-Alin iron and NWA 869, an ordinary (stony) chondrite — inside blocks of ice and heated them using a solar-simulator lamp. As expected, both meteorites melted their way down through the ice in time, but the iron meteorite sank further and faster. I bet you can guess why. Iron or metal conducts heat more efficiently than rock. Grab a metal camera tripod leg or telescope tube on a bitter cold night and you’ll know exactly what I mean. Metal conducts the heat away from your hand far better and faster than say, a piece of wood or plastic.
The researchers performed many trials with the same results and created a mathematical model showing that Sun-driven burrowing during the six months of Antarctic summer accounted nicely for the lack of iron meteorites seen in the stranding zones. Co-author Dr. Katherine Joy estimates that the fugitive meteorites are trapped between about 20-40 inches (50-100 cm) beneath the ice.
Who wouldn’t be happy to find this treasure? Dr. Barbara Cohen is seen with a large meteorite from the Antarctic’s Miller Range. Credit: Antarctic Search for Meteorites Program
You can imagine how hard it would be to dig meteorites out of Antarctic ice. It’s work enough to mount an expedition to pick up just what’s on the surface.
With the gauntlet now thrown down, who will take up the challenge? The researchers suggests metal detectors and radar to help locate the hidden irons. Every rock delivered to Earth from outer space represents a tiny piece of a great puzzle astronomers, chemists and geologist have been assembling since 1794 when German physicist Ernst Chladni published a small book asserting that rocks from space really do fall from the sky.
Like the puzzle we leave unfinished on the tabletop, we have a picture, still incomplete, of a Solar System fashioned from the tiniest of dust motes in the crucible of gravity and time.