Report: NOVA Earth from Space Documentary
Aired on February 13 2013, the PBS documentary titled ‘Earth from Space’ explores how the view of the earth has been revolutionized through satellites and spacecrafts. While there have been many occurrences that advance the fact that the earth is part of a larger interconnected universe, the PBS documentary sheds more light on this area. The two hour documentary shows how individual ecosystems and climates are part of the larger unit, and this has been made possible through satellite technology that enables a closer study of climate and geology. Through the satellites, the scientists have been able to follow dust storms from Africa as they influence weather events in North America. The documentary is divided into four different sections as discussed in the report that follows.
Antarctica and the plankton blooms
The first section of the documentary focuses on satellite images around the Antarctica in a period of one year. The narrator explains that the images being depicted were collected over a course of one year where the Antarctica in summer is the size of one and half times the size of the United States. During winter, the size increases and the Antarctica grows to the size of Africa. While the ice formation is only within the Antarctica, the narrator notes that its impact is widespread throughout the planet. In understanding the extent of the impact of the Antarctica ice, is by studying the power of ice in the Weddell Sea. The ice and gale causes the seawater to freeze where tiny microscopic crystals start growing and knitting themselves together. The crystals expel salt in the water as they bond, where the salt then forms brine that sinks downwards (PBS, 2013). More than two hundred billion tons of ice is formed every year in the Weddell Sea and releases trillions of tons of brine. In shedding insight on where all the brine ends up, the scientists use Jason, a satellite that is jointly operated by the French Space Agency and NASA. According to the narrator, Jason uses radar signals that are bounced off the ocean’s surface to measure its height while also revealing the shape of the seafloor.
Jason has provided the researchers with the ability to measure the sea surface in accurately mapping out submarine bathymetry. The narrator notes that Jason has high precision that it has the ability to detect very minor changes in the sea level by measuring the valleys and peaks of the terrain on the sea floor. Through the documentary, the viewer is able to understand just how much change the Jason satellite has brought to research and science activities. As David Adamec notes in the documentary, the satellite is 500 miles up in space and yet its accuracy is less than half of an inch. In further explaining what this accuracy means, Adamec notes that it is similar to placing an instrument in Washington DC and looking at a crowd’s toes in Boston. With such capabilities, the science and research areas have been revolutionized by this technology that is easing the ability to observe different attributes of the planet and its greater ecosystem.
In following up with the journey of the brine at the Weddell Sea, the video shows how the data from the satellite allows scientists to map three dimensional images of the ocean floor at the Weddell Sea. The three dimensional map of the ocean floor reveals vast chasm off the continental shelf of the Antarctica that is two miles deep and the descent of the brine into the ocean is followed where it eventually falls off this shelf (PBS, 2013). In further showing the development of technology allowing researchers to track and collect data, the video reveals the presence of other sensors that are attached to the sea floor and that allow the researchers to track the brine as it flows and sinks. The two sets of instruments which are the satellite and the sensors on the ocean floor allow the collection of data that when combined reveals the real nature of the ocean while also enabling the scientists to track the dense brine. From the data analysis from the two sets of instruments, scientists are able to reconstruct the journey of the dense brine from the Weddell Sea through the Antarctic continental shelf and into a two mile deep abyss on the ocean floor where it takes hundreds of years for it to resurface. Although scientists are yet to discover what happens next to the brine, computer animation has helped see the action of the undersea current where there is an endless loop of a worldwide circulation system (PBS, 2013).
The satellites and sensors have been helpful in the simulation of different activities on the ocean, but information from satellites has also revealed that the oceans do not work on their own. Ocean currents have an effect on the atmosphere above them in such a way that ocean currents have an effect on the climate. An example given is that North and South Carolina are usually warm due to the Gulf Stream that has its roots in the Antarctica. Essentially, Antarctica makes the earth hospitable by preventing wild swings in temperature and providing a stability that has allowed life to flourish. Still on the technological capability in showing the progression of events and life on planet earth, NASA’s MODIS is able to detect an upwelling of cold water off the coast of Peru from where it then identifies a green hue over the water. Through MODIS, the identification of the green shade is chlorophyll which implies that there is plat life and this comes from the planktons that is thriving from the minerals found on the earth’s crust. According to the narrator, the plankton is the basis of marine life and is at the base of the food chain. MODIS also shows just how fast the planktons disappear in just 72 hours as they die and sink to the ocean floor.
The Sahara diatom
From the coast of Peru, the narrator shifts the viewer’s attention to the Sahara Desert in North Africa where herders are travelling over the Bodele depression. As the narrator notes, the depression was covered by the largest freshwater lake whose floor is covered by diatomite (remains of ancient planktons). The view of the Sahara has been made possible by the Landsat 7 which is one of the latest satellites tasked with the study of the rock composition on planet earth. According to Charlie Bristow from the University of London, while the Lake’s size is over 1000 km long and 600 km wide, images from Landsat 7 allows the viewer to see the full extent of the lake basin through images visualized on a computer. Through the satellite images, the diatomite on the Lake’s floor can be easily mapped and as noted by the narrator, this diatomite forms a rich source of phosphorus that is needed by living things in energy production (PBS, 2013). The documentary then seeks to show the viewer the journey taken for this nutrient to re-enter the chain of life.
Through the METEOSAT 8 which is a European weather satellite, one can see as the wind takes up the diatomite and breaks it into fine powder lifted from the desert every day at noon. As seen from space, the large cloud of dust is blown across the continent where it is then drawn up to the sky at the Atlantic coast and taken all the way to the Amazon where the minerals dissolve in the rain water as it falls. In observing how the nutrients gain their way into the circle of life, the Terra satellite monitors the speed of vegetation growth and its color scanner shows an increase in chlorophyll level at the end of the rainy season. Such shows how events around the planet are interconnected.
The documentary then shifts focus to the oxygen used by living animals for metabolism. According to scientists, oxygen was essential for the evolution of intelligent and large mammals such as the human beings. The Aura satellite from NASA is being used by scientists to trace where the oxygen comes from through the study of the earth’s atmosphere. Through a computer visualization, one can see how changes in the earth’s atmosphere in about 24 hours takes place through the rise of oxygen during the day and carbon dioxide at night (PBS, 2013). With the visualization being made possible by satellites, the viewer can see how the Amazon uses up its oxygen and carbon dioxide in what is almost a closed system. The process of oxygen production begins with the rain in the Amazon where soil from this place is washed up in the river systems and takes organic materials as well as nutrients. The sediments move all the way to the Amazon delta where microscopic planktons grow and they make use of the nutrients to explode. The tiny planktons act as plants where they absorb carbon dioxide and give out oxygen. Again, the satellites have helped to show the interconnection between life and events on earth where planktons provide half the oxygen that human beings and other creatures use to survive.
Lightening and Nitrogen, lightening and fire
From the sustenance of planktons whose minerals come from the Sahara in a cyclical process, focus then shifts to how lightening contributes to life on earth. The view from space provides scientists with a better view of the electrical storms and buzzes taking place at the earth. According to Pier Sellers, one of the scientists, the lightning strikes seem to set each other off. In gaining a better understanding of how lightening influences life on earth, the scientists have used the TRMM satellite by NASA that has a high speed camera to detect the individual lightning bolts. The information gained from the satellite is that there are usually 40 strikes of lightning every second which translates to more than 3,000,000 strikes in a day (PBS, 2013). The tracing of how lightning is created goes as far back as the combination of sunlight and water vapor that results in thunderclouds. As moist air rises, it creates updrafts that change water vapor into ice particles within the clouds. With the water droplets and ice smashing into each other at high speeds, they create static electricity that builds up to a point where there is a tearing of the air molecules from which a lightning bolt is born.
While the bolt is not thicker than the thumb, its temperature is five times that of the sun and its burning through the atmosphere breaks the nitrogen molecules. Nitrogen is always seeking for something to bond with and this leads to a nitrogen-oxygen bond that creates nitrate which is an important nutrient. Through the satellites, there is a visualization of the nitrate that later dissolves in water droplets and falls on the ground with the rain. Nitrates are then absorbed by plants and this means that these nutrients enter our food chain as they become available to human beings following consumption of the plants. The whole process envisages the connection between different processes and the importance in the sustenance of life.
Lightening promotes life on earth in another way beyond nitrate production. According to the narrator, while wildfires in different places are caused by lightening and cause destruction of forests and life, satellites have enabled scientists to see the life giving power of these fires (PBS, 2013). Through the Terra satellites infrared, it is able to detect the location of any fire on the planet. The video shows a visualization of fire all around the year throughout the planet where fire burns up over 19 million square miles. Dead and diseases trees in the forests have nutrients that they release back to the earth but the process takes many years to completion. Fire shortens this lifecycle as it enters a rapid oxidation process, where the nutrients stored in the trees end up in ash. Further, the fires also burn dead animals within the forests floor and this returns the nutrients back to the earth. Following a fire, there will be growth of new vegetation as can be seen from forest re-growths, and this helps continue the cycle of life over time.
The documentary has shed light on the interconnectedness of life all across the earth through a precise follow up and analysis of phenomena as made possible by satellites developed for these and other functions. The ocean currents affect the ice flow at the poles that in turn produces brine with a connection to planktons that come from the nutrients on the ocean floor. Satellite imagery has also helped see the travelling of nutrients across the earth to finally produce planktons that replenish the air with oxygen thus allowing life on earth to continue. On the other hand, this oxygen also aids in the oxidation process through fire that speeds up the release of nutrients held by trees and dead animals on the forest floor. Also important within this cyclical flow of activities is the energy from the sun that triggers activities all around the globe including in the human bodies where the skin cells use this energy to create vitamins. While this has been the continual cyclical activities that connect life, it was not evident until scientists made use of the power of satellites to follow up activities from their development to how they influence life in other areas. The conclusion that can be drawn is that technology is facilitating a better understanding of the environment and how human beings have an important connection to the larger ecosystem. Further, each part of the larger ecosystem is vital in the progression of life on earth.
PBS. (2013). Earth from Space. Retrieved on March 18, 2017 from www.pbs.org/wgbh/nova/earth/earth-from-space.html.