The entire disk of the Earth lit during the equinox on September 22, 2013. Credit: Roscosmos / NTSOMZ / SRC "Planeta" / zelenyikot.livejournal.com
Here’s a fantastic view of our home planet taken by the Russian weather satellite Electro-L. And while Elektro-L can take gigantic photographs of the entire planet every 30 minutes, it only can get a fully-lit view like this just twice a year — at the spring and autumn equinoxes. This image was taken during the autumnal equinox on September 22, 2013.
Below is an animated gif of the view, going from day to night.
Animation of the Electro-L satellite’s view of Earth on September 22, 2013. Credit: Roscosmos / NTSOMZ / SRC “Planeta” / zelenyikot.livejournal.com
Elektro-L orbits Earth in a geostationary orbit 36,000 kilometers above the equator, and with the Sun exactly behind the satellite on the equinox — the day the north and south poles get the same amount of light — the entire disk is fully lit.
You can see the typhoon Usagi raging over Southeast Asia, clouds and rain over Russia and swirling clouds in the ocean near Antarctica.
Electro-L was launched in 2011 and is Russia’s first geostationary weather satellite. It’s a data hog – sending back 2.56 to 16.36 megabits per second, with resolution of 1 kilometer per pixel. You can see the big 5000 x 5000 pixel version at the Electro-L website.
Thanks to Vitaliy Egorov for sharing this image with UT. He has posted the images at his zelenyikot/livejournal website.
We’re in the middle of Summer here on Vancouver Island, the Sun is out, the air is warm, and the river is great for swimming.
Three months from now, it’s going to be raining and miserable.
Six months from now, it’s still going to be raining, and maybe even snowing.
No matter where you live on Earth, you experience seasons, as we pass from Spring to Summer to Fall to Winter, and then back to Spring again.
Why do we have variations in temperature at all? What causes the seasons?
If you ask people this question, they’ll often answer that it’s because the Earth is closer to the Sun in the summer, and further in the winter.
But this isn’t why we have seasons. In fact, during Winter in the Northern Hemisphere, the Earth is actually at the closest point to the Sun in its orbit, and then farthest during the Summer. It’s the opposite situation for the Southern hemisphere, and explains why their seasons are more severe.
So if it’s not the distance from the Sun, why do we experience seasons?
We have seasons because the Earth’s axis is tilted.
Consider any globe you’ve ever used, and you’ll see that instead of being straight up and down, the Earth is at a tilt of 23.5-degrees.
The Earth’s North Pole is actually pointed towards Polaris, the North Star, and the south pole towards the constellation of Octans. At any point during its orbit, the Earth is always pointed the same direction.
For six months of the year, the Northern hemisphere is tilted towards the Sun, while the Southern hemisphere is tilted away. For the next six months, the situation is reversed.
Whichever hemisphere is tilted towards the Sun experiences more energy, and warms up, while the hemisphere tilted away receives less energy and cools down.
Consider the amount of solar radiation falling on part of the Earth.
When the Sun is directly overhead, each square meter of Earth receives about 1000 watts of energy.
But when the Sun is at a severe angle, like from the Arctic circle, that same 1000 watts of energy is spread out over a much larger area.
This tilt also explains why the days are longer in the Summer, and then shorter in the Winter.
The longest day of Summer, when the Northern Hemisphere is tilted towards the Sun is known as the Summer Solstice.
And then when it’s tilted away from the Sun, that’s the Winter Solstice.
When both hemispheres receive equal amounts of energy, it’s called the Equinox. We have a Spring Equinox, and then an Autumn Equinox, when our days and night are equal in length.
So how does distance from the Sun affect us?
The distance between the Earth and has an effect on the intensity of the seasons.
The Southern Hemisphere’s Summer happens when the Earth is closest to the Sun, and their winter when the Earth is furthest. This makes their seasons even more severe.
You might be interested to know that the orientation of the Earth axis is actually changing.
Over the course of a 26,000 year cycle, the Earth’s axis traces out a great circle in the sky. This is known as the precession of the equinoxes.
At the halfway point, 13,000 years, the seasons are reversed for the two hemispheres, and then they return to original starting point 13,000 years later.
You might not notice it, but the time of the Summer Solstice comes earlier by about 20 minutes every year; a full day every 70 years or so.
I hope this helps you understand why the Earth – and any planet with a tilted axis – experiences seasons.
Average temperatures in the United States. Top, what they were in the 1950s. Bottom, the predictions for the 2090s. Credit: NASA
If you’re interested to see how warm your neighborhood will look like at 2090, here’s a chance. There’s new data available that has monthly climate projections for the continental United States at the size of a neighborhood, or about a half-mile (800 meters).
Readers who have moderate to advanced knowledge of how to manipulate datasets can see instructions for how to get the raw information here. As for everyone else, NASA briefly summarized how the information could be used for community planners to deal with the effects of climate change.
The map charts how rain and temperatures in the United States will be affected based on greenhouse gases. Because, of course, this is a projection, the researchers ran four different scenarios for the period between 1950 and 2099. Climate projections came from global climate models from the upcoming Inter-Governmental Panel on Climate Change 5th Assessment Report and historical surface observations.
The projections “may make it easier for resource managers to quantify anticipated climate change impacts on a wide range of conditions and resources important to local communities,” NASA stated.
The agency then provided a long list of research areas that would benefit, including “water supplies and winter snow packs, public health and the spread of insect-borne diseases, flood risk and potential impacts to critical urban infrastructure, wildfire frequency and severity, agricultural production, and wildlife and biodiversity.”
On this map of Nevada – northern California are superimposed graphics representing the average temperatures in the 1950s (top) and projected temperatures for the 2090s. Credit: NASA
As you can see from the climate map above, Nevada and California are highly affected by the projections, and officials in the region are paying attention, according to NASA.
“We are using the 800-meter downscaled datasets for conservation planning and resource management in the San Francisco Bay Area,” stated Stuart Weiss, a researcher at the Terrestrial Biodiversity Climate Change Collaborative in the San Francisco Bay Area.
“They provide an indispensable, if necessarily hazy, crystal ball into hydrological and ecological responses through the 21st century. It will be a very useful tool for climate change planning and adaptation that will be exported to the remainder of California and eventually the western United States.”
The data was crunched using supercomputers at NASA’s Ames Research Center, allowing the team to “produce the downscaled, high resolution climate dataset for the U.S. within months of release of the final global climate scenarios prepared for the next IPCC assessment report,” NASA added.
Water, ammonia, methanol and carbon dioxide could have come to Earth from cometary sources, according to a new study. Source: Lawrence Livermore National Laboratory
The energy of comets smashing into Earth billions of years ago could have generated life out of the building blocks of life that those extraterrestrial objects brought, according to new experiments published in a peer-reviewed study.
The finding comes after a team “shock compressed” an icy slush similar in composition to that found on comets, which are sometimes called “dirty snowballs” because they are a mixture of ice and rock. The compression, which researchers say is similar in intensity to comets hitting the Earth, generated amino acids – considered the basic bits of life.
“Our work shows that the basic building blocks of life can be assembled anywhere in the Solar System and perhaps beyond,” stated Zita Martins, a co-author of the paper who is with Imperial College London’s department of Earth science and engineering.
“However, the catch is that these building blocks need the right conditions in order for life to flourish. Excitingly, our study widens the scope for where these important ingredients may be formed in the Solar System and adds another piece to the puzzle of how life on our planet took root.”
An object entering a planet’s atmosphere. Credit: Imperial College London
Whether life arose on Earth, or was imported from other locations in the Solar System or universe, has been a hot-button topic for decades. Learning the answer not only has implications for our own planet, but also for understanding how likely it is that life exists in other Solar System planets and moons — not to mention moons or planets in other star systems.
The new experiment — which the researchers say uncovers evidence of a “cosmic factory” process for starting life — saw the team at the University of Kent and the Imperial College using a gas gun to send a projectile into an ice combination similar to what one would find a comet. After the impact, the researchers saw amino acids forming.
The work builds on research initially done by Nir Goldman, a scientist with the Lawrence Liverpool National Laboratory, who predicted the results based on simulations in the laboratory’s supercomputer. Goldman found that comets could have imported life’s building blocks (ammonia, methanol, carbon dioxide and water). Then, as they smashed into Earth, the energy produced could be enough to jump-start life.
The building blocks of proteins are molecules called amino acids. Most types of amino acids can exist in two different forms, one that is ‘left-handed’ and the other as ‘right-handed.’ Credit: NASA
“This process demonstrates a very simple mechanism whereby we can go from a mix of simple molecules, such as water and carbon-dioxide ice, to a more complicated molecule, such as an amino acid,” stated Mark Price, a co-author and physicist from the University of Kent.
“This is the first step towards life. The next step is to work out how to go from an amino acid to even more complex molecules such as proteins.”
You can read the research paper, which was published Sept. 15, on Nature Geoscience.
In a classic episode of this video series, I did the calculations for how fast the Earth is spinning.
We know the Earth is rotating, but why? Why is it spinning?
Why is everything in the Solar System spinning? And why is it mostly all spinning in the same direction?
It can’t be a coincidence. Look down on the Earth from above, and you’d see that it’s turning in a counter-clockwise direction. Same with the Sun, Mars and most of the planets.
4.54 billion years ago, our Solar System formed within a cloud of hydrogen not unlike the Orion Nebula, or the Eagle Nebula, with its awesome pillars of creation.
Then, it took some kick, like from the shockwave from a nearby supernova, and this set a region of the cold gas falling inward through its mutual gravity. As it collapsed, the cloud began to spin.
But why?
It’s the conservation of angular momentum.
Think about the individual atoms in the cloud of hydrogen. Each particle has its own momentum as it drifts through the void. As these atoms glom onto one another with gravity, they need to average out their momentum. It might be possible to average out perfectly to zero, but it’s really really unlikely.
Which means, there will be some left over. Like a figure skater pulling in her arms to spin more rapidly, the collapsing proto-Solar System with its averaged out particle momentum began to spin faster and faster.
This is the conservation of angular momentum at work.
As the Solar System spun more rapidly, it flattened out into a disk with a bulge in the middle. We see this same structure throughout the Universe: the shape of galaxies, around rapidly spinning black holes, and we even see it in pizza restaurants.
The Sun formed from the bulge at the center of this disk, and the planets formed further out. They inherited their rotation from the overall movement of the Solar System itself.
Over the course of a few hundred million years, all of the material in the Solar System gathered together into planets, asteroids, moons and comets. Then the powerful radiation and solar winds from the young Sun cleared out everything that was left over.
Without any unbalanced forces acting on them, the inertia of the Sun and the planets have kept them spinning for billions of years.
And they’ll continue to do so until they collide with some object, billions or even trillions of years in the future.
So are you still wondering, why does the Earth spin?
The Earth spins because it formed in the accretion disk of a cloud of hydrogen that collapsed down from mutual gravity and needed to conserve its angular momentum. It continues to spin because of inertia.
The reason it’s all the same direction is because they all formed together in the same Solar Nebula, billions of years ago.
Are Earthlings really Martians ? Did life arise on Mars first and then journey on meteors to our planet and populate Earth billions of years ago? Earth and Mars are compared in size as they look today.
Are Earthlings really Martians ?
Did life arise on Mars first and then journey on rocks to our planet and populate Earth billions of years ago? Earth and Mars are compared in size as they look today. NASA’s upcoming MAVEN Mars orbiter is aimed at answering key questions related to the habitability of Mars, its ancient atmosphere and where did all the water go. Story updated[/caption]
That’s the controversial theory proposed today (Aug. 29) by respected American chemist Professor Steven Benner during a presentation at the annual Goldschmidt Conference of geochemists being held in Florence, Italy. It’s based on new evidence uncovered by his research team and is sure to spark heated debate on the origin of life question.
Benner said the new scientific evidence “supports the long-debated theory that life on Earth may have started on Mars,” in a statement. Universe Today contacted Benner for further details and enlightenment.
“We have chemistry that (at least at the level of hypothesis) makes RNA prebiotically,” Benner told Universe Today. “AND IF you think that life began with RNA, THEN you place life’s origins on Mars.” Benner said he has experimental data as well.
First- How did ancient Mars life, if it ever even existed, reach Earth?
On rocks violently flung up from the Red Planet’s surface during mammoth collisions with asteroids or comets that then traveled millions of miles (kilometers) across interplanetary space to Earth – melting, heating and exploding violently before the remnants crashed into the solid or liquid surface.
An asteroid impacts ancient Mars and send rocks hurtling to space – some reach Earth. Did they transport Mars life to Earth? Or minerals that could catalyze the origin of life on Earth?
“The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock,” says Benner, of The Westheimer Institute of Science and Technology in Florida. That theory is generally known as panspermia.
To date, about 120 Martian meteorites have been discovered on Earth.
And Benner explained that one needs to distinguish between habitability and the origin of life.
“The distinction is being made between habitability (where can life live) and origins (where might life have originated).”
NASA’s new Curiosity Mars rover was expressly dispatched to search for environmental conditions favorable to life and has already discovered a habitable zone on the Red Planet’s surface rocks barely half a year after touchdown inside Gale Crater.
Furthermore, NASA’s next Mars orbiter- named MAVEN – launches later this year and seeks to determine when Mars lost its atmosphere and water- key questions in the Origin of Life debate.
Curiosity accomplished Historic 1st drilling into Martian rock at John Klein outcrop on Feb 8, 2013 (Sol 182) and discovered a habitable zone, shown in this context mosaic view of the Yellowknife Bay basin taken on Jan. 26 (Sol 169). The robotic arm is pressing down on the surface at John Klein outcrop of veined hydrated minerals – dramatically back dropped with her ultimate destination; Mount Sharp. Credit: NASA/JPL-Caltech/Ken Kremer-kenkremer.com/Marco Di Lorenzo
Of course the proposed chemistry leading to life is exceedingly complex and life has never been created from non-life in the lab.
The key new points here are that Benner believes the origin of life involves “deserts” and oxidized forms of the elements Boron (B) and Molybdenum (Mo), namely “borate and molybdate,” Benner told me.
“Life originated some 4 billion years ago ± 0.5 billon,” Benner stated.
He says that there are two paradoxes which make it difficult for scientists to understand how life could have started on Earth – involving organic tars and water.
Life as we know it is based on organic molecules, the chemistry of carbon and its compounds.
But just discovering the presence of organic compounds is not the equivalent of finding life. Nor is it sufficient for the creation of life.
And simply mixing organic compounds aimlessly in the lab and heating them leads to globs of useless tars, as every organic chemist and lab student knows.
Benner dubs that the ‘tar paradox’.
Although Curiosity has not yet discovered organic molecules on Mars, she is now speeding towards a towering 3 mile (5 km) high Martian mountain known as Mount Sharp.
Curiosity Spies Mount Sharp – her primary destination
Curiosity will ascend mysterious Mount Sharp and investigate the sedimentary layers searching for clues to the history and habitability of the Red Planet over billions of years. This mosaic was assembled from over 3 dozen Mastcam camera images taken on Sol 352 (Aug 2, 2013. Credit: NASA/JPL-Caltech/MSSS/ Marco Di Lorenzo/Ken Kremer-kenkremer.com
Upon arrival sometime next spring or summer, scientists will target the state of the art robot to investigate the lower sedimentary layers of Mount Sharp in search of clues to habitability and preserved organics that could shed light on the origin of life question and the presence of borates and molybdates.
It’s clear that many different catalysts were required for the origin of life. How much and their identity is a big part of Benner’s research focus.
“Certain elements seem able to control the propensity of organic materials to turn into tar, particularly boron and molybdenum, so we believe that minerals containing both were fundamental to life first starting,” says Benner in a statement. “Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there too.”
The second paradox relates to water. He says that there was too much water covering the early Earth’s surface, thereby causing a struggle for life to survive. Not exactly the conventional wisdom.
“Not only would this have prevented sufficient concentrations of boron forming – it’s currently only found in very dry places like Death Valley – but water is corrosive to RNA, which scientists believe was the first genetic molecule to appear. Although there was water on Mars, it covered much smaller areas than on early Earth.”
Parts of ancient Mars were covered by oceans, lakes and streams of liquid water in this artists concept, unlike the arid and bone dry Martian surface of today. Subsurface water ice is what remains of Martian water.
I asked Benner to add some context on the beneficial effects of deserts and oxidized boron and molybdenum.
“We have chemistry that (at least at the level of hypothesis) makes RNA prebiotically,” Benner explained to Universe Today.
“We require mineral species like borate (to capture organic species before they devolve to tar), molybdate (to arrange that material to give ribose), and deserts (to dry things out, to avoid the water problem).”
“Various geologists will not let us have these [borates and molybdates] on early Earth, but they will let us have them on Mars.”
“So IF you believe what the geologists are telling you about the structure of early Earth, AND you think that you need our chemistry to get RNA, AND IF you think that life began with RNA, THEN you place life’s origins on Mars,” Benner elaborated.
“The assembly of RNA building blocks is thermodynamically disfavored in water. We want a desert to get rid of the water intermittently.”
I asked Benner whether his lab has run experiments in support of his hypothesis and how much borate and molybdate are required.
“Yes, we have run many lab experiments. The borate is stoichiometric [meaning roughly equivalent to organics on a molar basis]; The molybdate is catalytic,” Benner responded.
“And borate has now been found in meteorites from Mars, that was reported about three months ago.
At his talk, Benner outlined some of the chemical reactions involved.
Although some scientists have invoked water, minerals and organics brought to ancient Earth by comets as a potential pathway to the origin of life, Benner thinks differently about the role of comets.
“Not comets, because comets do not have deserts, borate and molybdate,” Benner told Universe Today.
MAVEN is NASA’s next Mars orbiter and seeks to determine when Mars lost its atmosphere and water- key questions in the Origin of Life debate. MAVEN is slated to blastoff for Mars on Nov. 18, 2013. It is shown here with solar panels deployed as part of environmental testing procedures at Lockheed Martin Space Systems in Waterton, Colorado, before shipment to Florida in early August. Credit: Lockheed Martin
Benner has developed a logic tree outlining his proposal that life on Earth may have started on Mars.
“It explains how you get to the conclusion that life originated on Mars. As you can see from the tree, you can escape that conclusion by diverging from the logic path.”
Finally, Benner is not one who blindly accepts controversial proposals himself.
He was an early skeptic of the claims concerning arsenic based life announced a few years back at a NASA sponsored press conference, and also of the claims of Mars life discovered in the famous Mars meteorite known as ALH 84001.
“I am afraid that what we thought were fossils in ALH 84001 are not.”
The debate on whether Earthlings are really Martians will continue as science research progresses and until definitive proof is discovered and accepted by a consensus of the science community of Earthlings – whatever our origin.
On Nov. 18, NASA will launch its next mission to Mars – the MAVEN orbiter. Its aimed at studying the upper Martian atmosphere for the first time.
“MAVENS’s goal is determining the composition of the ancient Martian atmosphere and when it was lost, where did all the water go and how and when was it lost,” said Bruce Jakosky to Universe Today at a MAVEN conference at the University of Colorado- Boulder. Jakosky, of CU-Boulder, is the MAVEN Principal Investigator.
MAVEN will shed light on the habitability of Mars billions of years ago and provide insight on the origin of life questions and chemistry raised by Benner and others.
…………….
Learn more about Mars, the Origin of Life, LADEE, Cygnus, Antares, MAVEN, Orion, Mars rovers and more at Ken’s upcoming presentations
Sep 5/6/16/17: “LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM
Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM
Oct 9: “LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Princeton University, Amateur Astronomers Assoc of Princeton (AAAP), Princeton, NJ, 8 PM
The NASA P-3B's shadow on sea ice off of southeast Greenland during an IceBridge survey on Apr. 9, 2013. Flying at a low altitude allows IceBridge researchers to gather detailed data. Credit: NASA / Jim Yungel
There’s a “Chuck Norris fact” that says Chuck once went skydiving but promised never to do it again, saying one Grand Canyon is enough. But Chuck must have taken another jump millions of years ago.
Data gathered by NASA’s Operation IceBridge, an aerial science observation mission, has uncovered a previously unknown massive canyon in Greenland, hidden under a kilometer of ice.
The canyon, found by airborne radar data, has the same characteristics of a winding river channel like the Grand Canyon in Arizona. It is at least 750 kilometers (460 miles) long, making it longer than the Grand Canyon. In some places, it is as deep as 800 meters (2,600 feet), on scale with parts of the Grand Canyon. This immense feature is thought to predate the ice sheet that has covered Greenland for the last few million years.
“One might assume that the landscape of the Earth has been fully explored and mapped,” said Jonathan Bamber, professor of physical geography at the University of Bristol in the United Kingdom, and lead author of the study. “Our research shows there’s still a lot left to discover.”
While additional airborne radar data was used, the majority of the data was collected by IceBridge flights over Greenland during flights from 2009 to 2013. IceBridge’s Multichannel Coherent Radar Depth Sounder can see through vast layers of ice to measure its thickness and the shape of bedrock below.
In their analysis of the radar data, Bamber and his team discovered a continuous bedrock canyon that extends from almost the center of the island and ends beneath the Petermann Glacier fjord in northern Greenland.
At certain frequencies, radio waves can travel through the ice and bounce off the bedrock underneath. The amount of time the radio waves took to bounce back helped researchers determine the depth of the canyon. The longer it took, the deeper the bedrock feature.
The researchers believe the canyon plays an important role in transporting sub-glacial meltwater from the interior of Greenland to the edge of the ice sheet into the ocean. Evidence suggests that before the presence of the ice sheet, as much as 4 million years ago, water flowed in the canyon from the interior to the coast and was a major river system.
“It is quite remarkable that a channel the size of the Grand Canyon is discovered in the 21st century below the Greenland ice sheet,” said Studinger. “It shows how little we still know about the bedrock below large continental ice sheets.”
The IceBridge campaign will return to Greenland in March 2014 to continue collecting data on land and sea ice in the Arctic using a suite of instruments that includes ice-penetrating radar.
Bamber and his team had their findings published in the journal Science.
Earth Waves at Cassini on July 19, 2013- From more than 40 countries and 30 U.S. states, people around the world shared more than 1,400 images of themselves as part of the Wave at Saturn event organized by NASA's Cassini mission on July 19, 2013. The Cassini team created this image collage as a tribute to the people of Earth Credit: NASA/JPL-Caltech/People of Earth See link below to the absolutely gigantic full resolution version
Earth Waves at Saturn and Cassini on July 19, 2013
From more than 40 countries and 30 U.S. states, people around the world shared more than 1,400 images of themselves as part of the Wave at Saturn event organized by NASA’s Cassini mission on July 19, 2013. The Cassini team created this image collage as a tribute to the people of Earth
Credit: NASA/JPL-Caltech/People of Earth
See link below to the absolutely gigantic full resolution version [/caption]
On July 19, millions of Earthlings worldwide participated in NASA’s ‘Wave at Saturn’ campaign as the NASA Cassini Saturn orbiter turned about and imaged all of us.
Earthlings from 40 countries and 30 U.S. states heeded NASA’s call to photograph themselves while smiling and waving at Saturn and Cassini across 1 billion miles of interplanetary space and shared over 1400 images.
The results of all those images has now been assembled into a fabulous collage in the shape of our planet and released today (Aug. 21) by NASA and the Cassini team as a tribute to the People of Earth.
“Did you wave at Saturn and send us your photo? Then here’s looking at you!” NASA announced on the Cassini Facebook page.
This event was the first time that the citizens of Earth knew in advance that a distant interplanetary spacecraft was photographing portraits of our home planet and our Moon. NASA invited everyone to participate.
Photos flooded into NASA via Twitter, Facebook, Flickr, Instagram, Google+ and email.
Click here for the full resolution version. But be forewarned – it weighs in at over 26 MB and it’s far too big to post here.
The Day the Earth Smiled: Sneak Preview
In this rare image taken on July 19, 2013, the wide-angle camera on NASA’s Cassini spacecraft has captured Saturn’s rings and our planet Earth and its moon in the same frame. Image Credit: NASA/JPL-Caltech/Space Science Institute
“Thanks to all of you, near and far, old and young, who joined the Cassini mission in marking the first time inhabitants of Earth had advance notice that our picture was being taken from interplanetary distances,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif, in a statement.
“While Earth is too small in the images Cassini obtained to distinguish any individual human beings, the mission has put together this collage so that we can celebrate all your waving hands, uplifted paws, smiling faces and artwork.”
The Cassini imaging science team is still assembling the hundreds of images of Saturn and Earth snapped by the spacecraft as we were waving, to create individual color composites and a panoramic view of the ‘pale blue dot’ and the entire Saturnian system.
To capture all of Saturn and its wide swath of rings, Cassini’s wide angle camera snapped a mosaic of 33 footprints on July 19, 2013.
“At each footprint, images were taken in different spectral filters for a total of 323 images,” says Carolyn Porco, Cassini Imaging Team leader, Space Science Institute in Boulder, Colo.
Cassini took the pictures of Earth from a distance of about 898 million miles (1.44 billion kilometers) away from the home to every human being that has ever lived.
Here is our partial version of Cassini’s mosaic.
Partial context mosaic of the Earth and Saturn taken by NASA’s Cassini orbiter on July 19, 2013. This mosaic was assembled from five Cassini wide angle camera raw images and offers a sneak peek of the complete panorama. Earth at lower right. Credit: NASA/JPL-Caltech/Ken Kremer/Marco Di Lorenzo
It achieved orbit at Saturn in 2004 and has transmitted breathtaking images and science that revolutionized our understanding of the Saturnian system.
The mission is scheduled to continue until 2017 when it will commit a suicide death dive into the humongous gas giant.
Coincidentally, the first humans (Neil Armstrong and Buzz Aldrin) set foot on the Moon 44 years ago nearly to the day of Cassini’s Earth-Moon portrait on July 20, 1969 aboard Apollo 11.
JPL Waves at Saturn As NASA’s Cassini spacecraft turned its imaging cameras to Earth, scientists, engineers and visitors at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., gathered to wave at our robotic photographer in the Saturn system on July 19, 2013. Credit: NASA/JPL-Caltech
Polar mesospheric clouds shine over a midnight sunrise above Alaska on August 4, 2013 (NASA)
Looking for a new desktop background? This might do nicely: a photo of noctilucent “night-shining” clouds seen above a midnight Sun over Alaska, taken from the ISS as it passed over the Aleutian Islands just after midnight local time on Sunday, August 4.
When this photo was taken Space Station was at the “top of the orbit” — 51.6 ºN, the northernmost latitude that it reaches during its travels around the planet.
According to the NASA Earth Observatory site, “some astronauts say these wispy, iridescent clouds are the most beautiful phenomena they see from orbit.” So just what are they? Read on…
Found about 83 km (51 miles) up, noctilucent clouds (also called polar mesospheric clouds, or PMCs) are the highest cloud formations in Earth’s atmosphere. They form when there is just enough water vapor present to freeze into ice crystals. The icy clouds are illuminated by the Sun when it’s just below the horizon, after darkness has fallen or just before sunrise, giving them their eponymous property.
NLCs seen in the southern hemisphere in Jan. 2010 (NASA)
Noctilucent clouds have also been associated with rocket launches, space shuttle re-entries, and meteoroids, due to the added injection of water vapor and upper-atmospheric disturbances associated with each. Also, for some reason this year the clouds appeared a week early.
Some data suggest that these clouds are becoming brighter and appearing at lower latitudes, perhaps as an effect of global warming putting more greenhouse gases like methane into the atmosphere.
“When methane makes its way into the upper atmosphere, it is oxidized by a complex series of reactions to form water vapor,” said James Russell, the principal investigator of NASA’s Aeronomy of Ice in the Mesosphere (AIM) project and a professor at Hampton University. “This extra water vapor is then available to grow ice crystals for NLCs.”
A comparison of noctilucent cloud formation from 2012 and 2013 has been compiled using data from the AIM spacecraft. You can see the sequence here.
And for an incredible motion sequence of noctilucent clouds — taken from down on the ground — check out the time-lapse video below by Maciej Winiarczyk, coincidentally made at around the same time as the ISS photo above:
(The video was featured as the Astronomy Picture of the Day (APOD) for August 19, 2013.)
Horseshoe-shaped lateral moraines at the margin of the Penny Ice Cap on Baffin Island, Nunavut, Canada. Lateral moraines are accumulations of debris along the sides of a glacier formed by material falling from the valley wall. Credit: NASA / Michael Studinger
Enjoy this tour of the Arctic and Greenland, courtesy of the pilots of IceBridge, a six-year NASA mission to survey the ice at both of Earth’s poles. These views come from NASA’s P-3B aircraft, and the video is a selection of some of the best footage from the forward and nadir cameras mounted to the aircraft taken during IceBridge’s spring deployment over Greenland and the Arctic Ocean.
This airborne mission is collecting radar, laser altimetry, and other data on the changing ice sheets, glaciers, and sea ice of the Arctic and Antarctic. It is the largest airborne survey of Earth’s polar ice ever flown, and it will provide an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice.
Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA’s Ice, Cloud and Land Elevation Satellite (ICESat) — in orbit since 2003 — and ICESat-2, planned for late 2015. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations.
