Earth science Archives

June 29, 2014December 23, 2015 by Ken Kremer

NASA Set to Launch OCO-2 Observatory on July 1 – Sniffer of Carbon Dioxide Greenhouse Gas

NASA’s Orbiting Carbon Observatory-2 (OCO-2) at the Launch Pad
This black-and-white infrared view shows the launch gantry, surrounding the United Launch Alliance Delta II rocket with the Orbiting Carbon Observatory-2 (OCO-2) satellite onboard. The photo was taken at Space Launch Complex 2, Friday, June 27, 2014, Vandenberg Air Force Base, Calif. OCO-2 is set for a July 1, 2014 launch. Credit: NASA/Bill Ingalls[/caption]

After a lengthy hiatus, the workhorse Delta II rocket that first launched a quarter of a century ago and placed numerous renowned NASA science missions into Earth orbit and interplanetary space, as well as lofting dozens of commercial and DOD missions, is about to soar again this week on July 1 with NASA’s Orbiting Carbon Observatory-2 (OCO-2) sniffer to study atmospheric carbon dioxide (CO2).

OCO-2 is NASA’s first mission dedicated to studying atmospheric carbon dioxide, the leading human-produced greenhouse gas and the principal human-produced driver of climate change.

The 999 pound (454 kilogram) observatory is equipped with one science instrument consisting of three high-resolution, near-infrared spectrometers fed by a common telescope. It will collect global measurements of atmospheric CO2 to provide scientists with a better idea of how CO2 impacts climate change.

OCO-2's Delta II Rocket, First Stage At Space Launch Complex 2 on Vandenberg Air Force Base in California, the mobile service tower rolls away from the launch stand supporting the first stage of the Delta II rocket for NASA's Orbiting Carbon Observatory-2 mission. Three solid rocket motors (white) have been attached to the first stage. The photo was taken during operations to mate the rocket's first and second stages. Credit: NASA/Randy Beaudoin — OCO-2’s Delta II Rocket, First Stage At Space Launch Complex 2 on Vandenberg Air Force Base in California, the mobile service tower rolls away from the launch stand supporting the first stage of the Delta II rocket for NASA’s Orbiting Carbon Observatory-2 mission. Three solid rocket motors (white) have been attached to the first stage. The photo was taken during operations to mate the rocket’s first and second stages. Credit: NASA/Randy Beaudoin

The $467.7 million OCO-2 mission is set to blastoff atop the United Launch Alliance (ULA) Delta II rocket on Tuesday, July 1 from Space Launch Complex 2 at Vandenberg Air Force Base in California.

Liftoff is slated for 5:56 a.m. EDT (2:56 a.m. PDT) at the opening of a short 30-second launch window.

NASA TV will broadcast the launch live with countdown commentary beginning at 3:45 a.m. EDT (12:45 a.m. PDT): http://www.nasa.gov/multimedia/nasatv/

The California weather prognosis is currently outstanding at 100 percent ‘GO’ for favorable weather conditions at launch time.

The two stage Delta II 7320-10 launch vehicle is 8 ft in diameter and approximately 128 ft tall. It is equipped with a trio of strap on solid rocket motors. This marks the 152nd Delta II launch overall and the 51st for NASA since 1989.

The last time a Delta II rocket flew was nearly three years ago in October 2011 from Vandenberg for the Suomi National Polar-Orbiting Partnership (NPP) weather satellite.

The final Delta II launch from Cape Canaveral on Sept. 10, 2011 boosted NASA’s twin GRAIL gravity mapping probes to the Moon.

The Delta II will boost OCO-2 into a 438-mile (705-kilometer) altitude, near-polar orbit. Spacecraft separation from the rocket occurs 56 minutes 15 seconds after launch.

It will lead a constellation of five other international Earth monitoring satellites that circle Earth.

NASA's Orbiting Carbon Observatory-2, or OCO-2, inside the payload fairing in the mobile service tower at Space Launch Complex 2 on Vandenberg Air Force Base in California. The fairing will protect OCO-2 during launch aboard a United Launch Alliance Delta II rocket, scheduled for 5:56 a.m. EDT on July 1. OCO-2 is NASA’s first mission dedicated to studying atmospheric carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth’s climate. Credit: NASA/30th Space Wing USAF — NASA’s Orbiting Carbon Observatory-2, or OCO-2, inside the payload fairing in the mobile service tower at Space Launch Complex 2 on Vandenberg Air Force Base in California. The fairing will protect OCO-2 during launch aboard a United Launch Alliance Delta II rocket, scheduled for 5:56 a.m. EDT on July 1. OCO-2 is NASA’s first mission dedicated to studying atmospheric carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth’s climate. Credit: NASA/30th Space Wing USAF

The phone-booth sized OCO-2 was built by Orbital Sciences and is a replacement for the original OCO which was destroyed during the failed launch of a Taurus XL rocket from Vandenberg back in February 2009 when the payload fairing failed to open properly.

OCO-2 is the second of NASA’s five new Earth science missions launching in 2014 and is designed to operate for at least two years during its primary mission. It follows the successful blastoff of the joint NASA/JAXA Global Precipitation Measurement (GPM) Core Observatory satellite on Feb 27.

Orbiting Carbon Observatory-2 (OCO-2) mission will provide a global picture of the human and natural sources of carbon dioxide, as well as their “sinks,” the natural ocean and land processes by which carbon dioxide is pulled out of Earth’s atmosphere and stored, according to NASA..

“Carbon dioxide in the atmosphere plays a critical role in our planet’s energy balance and is a key factor in understanding how our climate is changing,” said Michael Freilich, director of NASA’s Earth Science Division in Washington.

“With the OCO-2 mission, NASA will be contributing an important new source of global observations to the scientific challenge of better understanding our Earth and its future.”

Artist's rendering of NASA's Orbiting Carbon Observatory (OCO)-2, one of five new NASA Earth science missions set to launch in 2014, and one of three managed by JPL. Credit: NASA-JPL/Caltech — Artist’s rendering of NASA’s Orbiting Carbon Observatory (OCO)-2, one of five new NASA Earth science missions set to launch in 2014, and one of three managed by JPL. Credit: NASA-JPL/Caltech

It will record around 100,000 CO2 measurements around the world every day and help determine its source and fate in an effort to understand how human activities impact climate change and how we can mitigate its effects.

At the dawn of the Industrial Revolution, there were about 280 parts per million (ppm) of carbon dioxide in Earth’s atmosphere. As of today the CO2 level has risen to about 400 parts per million.

Stay tuned here for Ken’s continuing OCO-2, GPM, Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more Earth & Planetary science and human spaceflight news.

Ken Kremer

Blastoff of twin GRAIL A and B lunar gravity mapping spacecraft on a Delta II Heavy rocket on Sept. 10 from Pad 17B Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT. Credit: Ken Kremer/kenkremer.com — Blastoff of twin GRAIL A and B lunar gravity mapping spacecraft on a Delta II Heavy rocket on Sept. 10, 2011, from Pad 17B Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT. Credit: Ken Kremer/kenkremer.com

January 23, 2014December 23, 2015 by Elizabeth Howell

Dusty, Windy And Damp: Five NASA Probes To Hunt Down Climate Change in 2014

Artist's conception of NASA's Orbiting Carbon Observatory, which will examine carbon dioxide in the atmosphere (and its effect on climate change) after an expected launch in July 2014. Credit: NASA

How badly will climate change affect our planet? Different models tell us different things, and that’s partly because we need more precise information about the factors that warm the world. How much is sea level rising? What are the levels of carbon dioxide in the atmosphere? All of these things must be known.

NASA expects to launch five Earth science missions this year, which is the biggest roster in more than a decade. They’ll track rainfall, seek water hiding in soil, and examine carbon dioxide and ocean winds around the world. Here’s a quick rundown of the busy launch schedule:

Global Precipitation Measurement (GPM) Core Observatory (Feb. 27): This will be the first of a series of satellites to look at snow and rain from space. “This new information will help answer questions about our planet’s life-sustaining water cycle, and improve water resource management and weather forecasting,” NASA stated. This joint spacecraft with the Japanese Aerospace Exploration Agency (JAXA) will launch from Japan’s Tanegashima Space Center on a H-IIA rocket. GPM was built at NASA’s Goddard Space Flight Center in Maryland.

ISS-RapidScat (June 6): This sensor will sit on the International Space Station and monitor ocean winds (including storms and hurricanes). What’s interesting about this mission is its use of old parts, NASA points out, as well as the decision to mount it on a station rather than take the more expensive route of making it a separate satellite. The probe will launch on a SpaceX Dragon spacecraft (aboard a SpaceX Falcon 9 rocket) from Florida’s Cape Canaveral Air Force Station as part of a regular commercial resupply flight.

Artist's conception of how ISS-RapidScat will work. Credit: NASA/JPL-Caltech/Johnson Space Center — Artist’s conception of how ISS-RapidScat will work. Credit: NASA/JPL-Caltech/Johnson Space Center

Orbiting Carbon Observatory (OCO)-2 (July): NASA plans to take a second crack at this type of satellite after the OCO launch failure in 2009. The satellite will seek out carbon dioxide to better understand where it is emitted (in both natural and artificial processes) and how it moves through the water, air and land. This will launch from California’s Vandenberg Air Force Base on a Delta II rocket. OCO-2 will be managed by NASA’s Jet Propulsion Laboratory in California.

Cloud-Aerosol Transport System (CATS) (Sept. 12): This technology demonstration project will use lasers, in three wavelengths, to examine tiny particles borne into the atmosphere from phenomena such as pollution, smoke, dust and volcanoes. “These aerosol particles pose human health risks at ground level and influence global climate through their impact on cloud cover and solar radiation in Earth’s atmosphere,” NASA stated. This will also leave Earth aboard a SpaceX resupply flight from Cape Canaveral.

Soil Moisture Active Passive (SMAP) mission (November): Will check out the moisture level of soil, with the aim of refining “predictions of agricultural productivity, weather and climate,” NASA stated. Also managed by JPL, this satellite will spend its time in an almost-polar “sun-synchronous” orbit that keeps the sun’s illumination below constant during SMAP’s turns around the Earth. SMAP will launch from Vandenberg on a Delta II rocket.

Source: NASA

September 10, 2009May 4, 2017 by Fraser Cain

K-T Boundary

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What killed the dinosaurs? That’s a question that has puzzled paleontologists since dinosaurs were first discovered. Maybe the global climate changed, maybe they were killed by disease, volcanoes, or the rise of mammals. But in the last few decades, a new theory has arisen; an asteroid strike millions of years ago drastically changed the Earth’s environment. It was this event that pushed the dinosaurs over the edge into extinction. What’s the evidence for this asteroid impact? A thin dark line found in layers of sediment around the world; evidence that something devastating happened to the planet 65 million years ago. This line is known as the K-T boundary.

What is the K-T boundary? K is actually the traditional abbreviation for the Cretaceous period, and T is the abbreviation for the Tertiary period. So the K-T boundary is the point in between the Cretaceous and Tertiary periods. Geologists have dated this period to about 65.5 million years ago.

When physicist Luis Alvarez and geologist Walter Alvarez studied the K-T boundary around the world, they found that it had a much higher concentration of iridium than normal – between 30-130 times the amount of iridium you would expect. Iridium is rare on Earth because it sank down into the center of the planet as it formed, but iridium can still be found in large concentrations in asteroids. When they compared the concentrations of iridium in the K-T boundary, they found it matched the levels found in meteorites.

The researchers were even able to estimate what kind of asteroid must have impacted the Earth 65.5 million years ago to throw up such a consistent layer of debris around the entire planet. They estimated that the impactor must have been about 10 km in diameter, and release the energy equivalent of 100 trillion tons of TNT.

When that asteroid struck the Earth 65.5 million years ago, it destroyed a region thousands of kilometers across, but also threw up a dust cloud that obscured sunlight for years. That blocked photosynthesis in plants – the base of the food chain – and eventually starved out the dinosaurs.

Researchers now think that the asteroid strike that created the K-T boundary was probably the Chicxulub Crater. This is a massive impact crater buried under Chicxulub on the coast of Yucatan, Mexico. The crater measures 180 kilometers across, and occurred about 65 million years ago.

Geologists aren’t completely in agreement about the connection between the Chicxulub impact and the extinction of the dinosaurs. Some believe that other catastrophic events might have helped push the dinosaurs over the edge, such as massive volcanism, or a series of impact events.

We have written many articles about the K-T boundary for Universe Today. Here’s an article about how the dinosaurs probably weren’t wiped out by a single asteroid, and here’s an article about how asteroids and volcanoes might have done the trick.

Here’s more information from the USGS, and an article from NASA.

We have recorded an episode of Astronomy Cast all about asteroid impacts. Listen to it here: Episode 29: Asteroids Make Bad Neighbors.

Reference:
USGS

June 23, 2009December 24, 2015 by aalla

Continental Drift Theory

In elementary school, every teacher had one of those pull-down maps of the world to teach geography. On occasion, I thought the largest land masses, known as continents, reminded me of pieces in a jigsaw puzzle. They just seemed like they should fit together, somehow. Not until I took Earth Science, in 8TH grade, did I discover my earlier idea was correct. My teacher explained about a phenomenon, known as, The Continental Drift Theory. He said that some German had the same idea I did.

The man my teacher mentioned, Alfred Wegener (Vay gen ner), developed The Continental Drift Theory in 1915. He was a meteorolgist and a geologist. His theory basically said that, at one time, there existed one large supercontinent, called, Pangea, pan, meaning all-encompassing, and, gea, meaning the Earth. He went on to suggest that, seismic activity, such as erthquakes, volcanic eruptions, and tsunamis, also called tidal waves, eventually created fissures, or cracks in the Earth. As these fissures became larger, longer, and deeper, 7 pieces of Pangea broke off and, over time, drifted to the places where they are now. These 7 large pieces of land are what we now call, continents. They are: North America; South America; Europe; Asia; Africa; Antarctica; and, Australia. Some people refer to the country as Australia, and the continent as, Oceania. They do this because there are other countries, such as New Zealand, included as a part of that particular continent.

At the time, people thought Wegener was, well, “nuts.” Only in the 1950s did people begin to take his idea seriously. According to the United States Geological Survey (the USGS), thanks to the use of the submarine and the technology developed during World War II, scientists learned a lot about the Ocean Floor. When they found out that it was not as old as the Crust, or Surface, of the Earth, sicentists had to ask themselves, “Why?”

The answers have to do with earthquakes, volcanoes, and magnetism. When the Earth cracks, molten magma, from the middle of the Earth, known as the Mantle, works its way to the surface, where it becomes known as, lava. That lava melts away some of the older layers; then, when the water cools that lava, it forms a new layer of Earth. For that reason, if scientists tried to determine the age of the Earth from samples taken from the Ocean Floor, they would be very wrong.

That same equipment also helped scientists recognize that heavy amounts of basalt, a volcanic rock that contains high amounts of iron, could throw compasses off course. This information provided one more pieces to the puzzle. Now, scientists recognize that the North and South Poles were not always where they currently are.

The Earth changes every day. Although we might not notice it, the continents move all the time. We don’t only revolve, or spin, around the Sun. We also drift across the surface of the planet.

The United States Geological Survey has some excellent information on this topic.

University Today has some other fabulous material about this and related topics, including Earth, Barely Habitable?, by Fraser Cain begin_of_the_skype_highlighting end_of_the_skype_highlighting, and Interesting Facts About Planet Earth.

You can also read or listen to Episode 51: Earth, of Astronomy Cast, also produced by Universe Today.

Sources:
http://en.wikipedia.org/wiki/Continental_drift
http://www.ucmp.berkeley.edu/history/wegener.html
http://pubs.usgs.gov/gip/dynamic/historical.html

June 5, 2009December 24, 2015 by Fraser Cain

Barcena Volcano

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Barcena is a volcano located on the island of San Benedicto, the third largest island of the Revillagigedo Islands. The whole island is only about 4.8 km by 2.4 km and Barcena takes up a good chunk of the southern end. Barcena rises to an elevation of 332 meters, forming a volcanic crater.

There has only been on eruption from Barcena in recorded history, but it was a big one. On August 1, 1952, Barcena had a severe Vulcanian eruption measuring 3 on the Volcanic Explosivity Index. It released huge pyroclastic flows that rolled over the entire island, covering it in ash and pumice to a depth of 3 meters. Within less than 2 weeks, it had created a new volcanic cone more than 300 meters high. A second series of eruptions started up later in the year, releasing magma that broke out of the cone and flowed into the ocean. By late 1953, the volcano went dormant again.

The eruption wiped out all the plants and wildlife on the island, making the San Benedicto Rock Wren extinct. Within a few years the plants and wildlife made a return, although the island still looks barren.

We have written many article about volcanoes for Universe Today. Here’s an article about Tacana, a tall stratovolcano that straddles the border between Mexico and Guatemala. And here’s an article about Paricutin, a volcano that suddenly appeared in a farmer’s cornfield.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.

May 27, 2009December 24, 2015 by Fraser Cain

Basalt

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Basalt is a hard, black volcanic rock with less than 52% silica. Because of this low silica content, basalt has a low viscosity (thickness), and so it can flow for long distances after erupting from a volcano. During an eruption, a basalt lava flow can easily move more than 20 km away from a vent. Basalt is the most common rock type in the Earth’s crust. In fact, most of the ocean floor is made up of basalt.

Basalt is made up of dark colored materials like pyroxene and olivine, but it also contains lighter minerals like feldspar and quartz. These crystals form because the lava cools slowly after erupting out of a volcano. Although a lava flow might look cool shortly after an eruption, it might take months or even years to cool all the way through. The crystals are bigger in the middle of a cooled lava flow because that part had longer to cool. If a lava flow cools quickly, like when it falls into a lake or ocean, it becomes a glass-like rock called obsidian. This is because the crystals in the rock don’t have time to form.

Shield volcanoes are made up entirely of basalt lava eruptions. A good example of this are the volcanoes Mauna Loa and Mauna Kea on the Big Island of Hawaii. Over hundreds of thousands of years, they have built up tall volcanoes that are extremely wide because of the fast flowing basalt lava.

Geologists have found large outpourings of lava covering hundreds of kilometers of land called flood basalt. The largest of these is known as the Siberian Traps in northern Russia. This is a region of 1.5 million square kilometers covered by basalt.

We have written many articles about volcanoes for Universe Today. Here’s an article about obsidian, and here’s an article about different types of lava.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.

April 22, 2009September 16, 2016 by Fraser Cain

What are Active Volcanoes?

Geologists classify volcanoes into three distinct groups: dormant, extinct and active volcanoes. Dormant volcanoes haven’t erupted in a long time, but they could again; extinct volcanoes have erupted for thousands of years and might be dead. Active volcanoes, on the other hand, erupted recently, and they’re probably going to erupt again soon.

There are approximately 500 active volcanoes in the world today, not including those underneath the oceans. In fact, as you read these words, there are probably 20 volcanoes erupting right now. Between 50-70 volcanoes are erupting every year, 160 have erupted in the last decade. And there are about 550 that have erupted since the beginning of recorded history.

The definition of an active volcano is difficult to pin down, since single volcanoes can have networks of volcanic vents across their flanks. And Iceland, there can be eruptions along volcanic fields hundreds of kilometers long. At Mexico’s Michoacan-Guanajuanto field, there are 1,400 cinder cones, maars and shield volcanoes coming from a single magma chamber.

And these are just the volcanoes on land. Scientists estimate that 3/4 of the lava that reaches the Earth’s surface happens underwater at the submarine midocean ridges.

So when does a volcano become dormant or extinct? A volcano is active if it’s currently erupting or showing signs of unrest. The Smithsonian Global Volcanism Program defines an active volcano as having erupted within the last 10,000 years. A volcano finally goes extinct when there’s no lava supply in the magma chamber beneath the volcano.

We have written many articles about volcanoes for Universe Today. Here’s an article about dormant volcanoes, and here’s an article about extinct volcanoes.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.

April 22, 2009December 24, 2015 by Fraser Cain

A’a Lava

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There are several different kinds of lava, depending on the chemical composition and temperature of the molten rock that erupts from a volcano. The smooth variety is called pahoehoe, and the rougher variety is known as a’a (pronounced ah-ah). A’a is a Hawaiian word meaning “stony with rough lava”.

If you’ve ever been to the Big Island of Hawaii and gone for a hike, you’ve seen a’a lava. It’s incredibly rough and jagged black rock that takes forever to walk across; and tears your shoes apart as you go.

During an eruption, a’a lava comes out of the volcano as a very thick (viscous) lava that travels very slowly. The inside of an a’a lava flow is thick and dense. Surrounding this thick dense core is a sharp spiny surface of cooling rock. These fragments of rock are carried on the top of the a’a lava flow and make a crunching grinding sound as the lava flows downhill.

Once the lava flow stops, it can take weeks or even years for the lava to harden completely. The interior dense core hardens in place with the jagged fragments surrounding it. This is why old a’a flows are so sharp and jagged.

A’a flows move slowly – you could easily outrun one – but they move fast enough to tear down buildings, cover roads, and destroy vegetation.

The smoother pahoehoe lava can turn into a’a lava as it gets further downhill. This happens because of the delicate balance of gas content in the lava, the changes in lava viscosity, and the rate of deformation as the lava flows and cools. Once this balance changes, the pahoehoe can change into a’a. Of course, a’a lava never changes back into pahoehoe.

We have written many articles about volcanoes for Universe Today. Here’s an article about lava tubes on Pavonis Mons… on Mars. And here’s an article about the dark lava floor of crater Billy.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.

March 17, 2009December 24, 2015 by Fraser Cain

Cinder Cone Volcanoes

Cinder cone Paricutin. Image credit: USGS

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Picture a volcano in your mind. You’re probably thinking of a cinder cone volcano, the simplest type of volcano. Cinder cone volcanos have steep sides with a bowl-shaped crater at the top.

Cinder cone volcanoes grow from a single vent in the Earth’s crust. Gas-charged lava is blown violently out of the volcano’s central vent, and the ash and rocks rain down around the vent. After multiple eruptions, the volcano takes on the familiar cone shape, with the erupted rubble forming the steep slopes. Cinder cones rarely grow much taller than 300 meters above their surroundings, and they’re common in western North America, and wherever there’s volcanic activity.

Although they can be solitary structures, cinder cones are often associated with other kinds of volcanoes, like shield volcanoes and stratovolcanoes (or a composite volcano). For example, geologists have discovered more than 100 cinder cones on the sides of Hawaii’s Mauna Kea, one of the biggest volcano in the world. Each cinder cone comes from a vent that opened up on the sides of the volcano.

One of the most famous cinder cone volcanoes erupted out of a Mexican corn field in 1943. The volcano erupted for 9 years, and quickly built up the cinder cone to 424 meters, and covered 25 km² of fields in lava flows and rubble. Nearby towns were eventually buried in ash by the eruptions.

We have written many articles about volcanoes for Universe Today. Here’s an article about the biggest volcano on Earth, and here’s one about the largest volcano in the Solar System.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.

February 18, 2009December 24, 2015 by Fraser Cain

Albedo of the Earth

The albedo of the Earth is 0.367.

That’s the simple answer, now here’s the more complex one. Astronomers use the term “albedo” to define the amount of light that an object in the Solar System reflects. For example, if a planet was perfectly shiny, it would have an albedo of 1.00; it would reflect 100% of the light that hit it. If a planet was perfectly dark, it would have an albedo of 0, and so it would reflect 0% of the light that struck it.

The object with the highest albedo in the Solar System is Saturn’s moon Enceladus, with an albedo of 99%. On the other hand, asteroids can have albedos as low as 4%. The Earth’s moon has an albedo of about 7%. Can you imagine if we had Enceladus for a moon? Now that would be bright.

The albedo of the Earth is very important because it helps define the temperature of the planet. Fresh snow has an albedo of 90%, while the ocean has a very low albedo; land areas range from 0.1 to 0.4.

NASA’s Terra and Aqua satellites are constantly measuring the albedo of the Earth with their MODIS instruments, to help detect any evidence that the albedo is changing over time.

We have written many articles about the Earth for Universe Today. Here’s an article about how scientists track Earthshine on the Moon. And here’s a more detailed article about the albedo of the Moon.

Want more resources on the Earth? Here’s a link to NASA’s Human Spaceflight page, and here’s NASA’s Visible Earth.

We have also recorded an episode of Astronomy Cast about Earth, as part of our tour through the Solar System – Episode 51: Earth.