Earth Archives

December 10, 2009December 24, 2015 by Nancy Atkinson

Earth’s Atmosphere Came from Outer Space

A new study from the University of Heidelberg suggests that flash-heating and carbon depletion could have been intrinsic to the emergence and evolution of life on Earth. Credit: NASA

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A new study finds the gases which formed the Earth’s atmosphere – as well as its oceans – did not come from inside the Earth but from comets and meteorites hitting Earth during the Late Heavy Bombardment period. A research team tested volcanic gases to uncover the new evidence. “We found a clear meteorite signature in volcanic gases,” said Dr. Greg Holland the project’s lead scientist. “From that we now know that the volcanic gases could not have contributed in any significant way to the Earth’s atmosphere. Therefore the atmosphere and oceans must have come from somewhere else, possibly from a late bombardment of gas and water rich materials similar to comets.”

Holland said textbook images of ancient Earth with huge volcanoes spewing gas into the atmosphere will have to be rethought.

According to the theory of the Late Heavy Bombardment, the inner solar system was pounded by a sudden rain of solar system debris only 700 million years after it formed, which likely had monumental effects on the nascent Earth. So far, the evidence for this event comes primarily from the dating of lunar samples, which indicates that most impact melt rocks formed in this very narrow interval of time. But this new research on the origin of Earth’s atmosphere may lend credence to this theory as well.

The researchers analyzed the krypton and xenon found in upper-mantle gases leaking from the Bravo Dome gas field in New Mexico. They found that the two noble gases have isotopic signatures characteristic of early Solar System material similar to me teorites instead of the modern atmosphere and oceans. It therefore appears that noble gases trapped within the young Earth did not contribute to Earth’s later atmosphere.
The study is also the first to establish the precise composition of the Krypton present in the Earth’s mantle.

“Until now, no one has had instruments capable of looking for these subtle signatures in samples from inside the Earth – but now we can do exactly that,” said Holland.

The team’s research, “Meteorite Kr in Earth’s Mantle Suggests a Late Accretionary Source for the Atmosphere” was published in the journal Science.

Sources: Science, EurekAlert

December 9, 2009December 24, 2015 by Fraser Cain

Earth’s Mass

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The Earth’s mass is 5.9736 x 10²⁴ kg. That’s a big number, so let’s write it out in full: 5,973,600,000,000,000,000,000,000 kg. You could also say the Earth’s mass is 5.9 sextillion tonnes. Phew, that’s a lot of mass.

That sounds like a lot, and it is, but the Earth has a fraction of the mass of some other objects in the Solar System. The Sun has 333,000 times more mass than the Earth. And Jupiter has 318 times more mass. But then there are some less massive objects too. Mars has only 11% the mass of the Earth.

Because of its high mass for its size, Earth actually has the highest density of all the planets in the Solar System. The density of Earth is 5.52 grams per cubic centimeter. The high density comes from the Earth’s metallic core, which is surrounded by the rocky mantle. Less dense planets, like Jupiter, are just made up of gases like hydrogen.

We’ve written several articles about the mass of planets in the Solar System. Here’s an article about the mass of Mercury, and here’s an article about the mass of the Sun.

If you’d like more information on the Earth mass, check out NASA’s Solar System Exploration Guide on Earth. And here’s a link to NASA’s Earth Observatory.

We’ve also recorded an episode of Astronomy Cast all about the Earth. Listen here, Episode 51: Earth.

December 7, 2009December 24, 2015 by Abby Cessna

Tallest Mountains

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There are many tall mountains around the world as well as on other worlds. Mount Everest is the highest mountain in the world at 8,848 meters. Mauna Kea is the tallest mountain in the world. The tallest mountain is measured from base to top while the highest mountain is measured from sea level to the top. Everest is located in the Himalayan mountain range in Nepal and near Tibet. Mauna Kea is located in Hawaii and is 10,200 meters from base to tip. From sea level though, it is only about 4,205 meters tall. Mauna Kea is an extinct shield volcano.

These are not the only tall mountains though. K2 is in the Karakoram mountain range on the border of Pakistan and China. It is 8,612 meters tall and is generally considered the second tallest mountain in the world. The Himalayans are home to many tall mountains besides Mount Everest. This includes Mount Kangchenjunga at 8,586 meters and Mount Lhotse I at 8,501 meters.

Most of the world’s tallest mountains are located in Asia; however, there are a number of tall mountains that are located on other continents. The seven tallest mountains in different continents are known as the Seven Summits. Climbing all seven mountains is a mountaineering challenge that was started in the 1980’s.The first of these is Mount Everest. Another summit is Aconcagua, which is a mountain in Argentina in South America. At approximately 6,962 meters, it is the tallest mountain in the Americas. North America’s tallest mountain is Mount McKinley at 6,194 meters. Mount Kilimanjaro can be found in Tanzania in the continent of Africa and is 5,895 meters tall. The large summit of Mount Kilimanjaro is covered with an ice cap that is receding and according to scientists will eventually be gone. Mount Elbrus, the tallest mountain in Europe at 5,642 meters, can be found in Russia. Vinson Massif is Antarctica’s tallest mountain at 4,897 meters. It is also very large being 21 kilometers long and 13 kilometers wide. Australia-Oceania’s largest mountain can be found in Indonesia. At 4,884 meters, it is Puncak Jaya, which is also known as the Carstensz Pyramid.

The tallest mountain that we know of is not even on Earth. It is located on Mars and is known as Olympus Mon. A shield volcano, Olympus Mon is 27,000 meters tall. Mars is not the only other planet with tall mountains though. Venus’ Maxwell Montes is 11,000 meters tall. Satellites also have tall mountains including our Moon, which has Mons Huygens at 4,700 meters tall. The moon Io has a mountain, Boösaule Montes, which is approximately 17,000 meters tall.

Universe Today has articles on tallest mountain and tallest mountain in the Solar System.

For more information, you should take a look at what are the world’s tallest mountains and highest mountains.

Astronomy Cast has an episode on Earth you will find interesting.

Sources:
http://en.wikipedia.org/wiki/List_of_highest_mountains

November 20, 2009November 3, 2021 by Nancy Atkinson

What If Earth Had Rings?

Earth's Rings over San Bernadino. Credit: Kevin Gill (CC BY-SA 2.0)

Here’s a video that poses — and answers — an interesting question: what would Earth look like if it had rings like Saturn? This animation was done by artist Roy Prol, and it shows not only how the rings would look from space, but also the view Earthlings would have of the rings.

Prol says the ring views from Earth’s surface were created according to the location’s latitude and the viewer’s orientation, and that the size of the rings was calculated respecting the Roche limit for the Earth. As you can se in the video, the rings would look different, depending on where you were on our planet. A very intriguing concept, and the video is very well done.

The only bad thing about Earth having rings is that we probably wouldn’t have our beautiful Moon. Imagine, instead of all the songs, poems and paintings of the Moon over the past centuries, we’d have odes to our rings.

One of our favorite image editing artists is Kevin Gill, and he’s also created imagery of Earth having rings, such as our lead image, which shows Earth’s Rings over San Bernadino, California and this one, below:

Earth’s Rings from New Hampshire. Credit: Kevin Gill (CC BY-SA 2.0)

October 26, 2009December 24, 2015 by Nancy Atkinson

The Stats Are In: No Global Cooling

Global Temperature graph. Credit: National Climatic Data Center, via the Associated Press.

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The idea that the world is now cooling has been repeated in opinion columns, talk radio, pundit television and more. After a poll was released last week indicating that only 57 percent of Americans now believe there is strong scientific evidence for global warming, which is down from 77 percent in 2006, Seth Borenstein from the Associated Press decided to check out what the statistics are really saying about global warming or cooling. In a blind test, Borenstein sent accumulated ground temperature data from the past 130 years to four independent statisticians. He disguised the sources (NASA, NOAA and British meteorological data) and didn’t tell the statisticians what the numbers represented; he asked them to just look for trends in the data. The experts found no true temperature declines over time; additionally, the last ten years comprise not only the highest data set in the record, but they also have a continued, positive trend.

It seems recent weather trends have been cool — 2008 was cooler than previous years, especially the really hot years of 1998 and 2005.

Global land and ocean temperature indexes. Credit: Goddard Institute for Space Studies.

Borenstein wanted to know if this was a longer climate trend or just weather’s normal ups and downs. All four of the statisticians agreed independently the statistics overall clearly show an upward trend of warming. Also included was a data set of satellite temperature data that is often favored by skeptics of global warming. Same story there: global temps are on the rise.

The ups and downs during the last decade, which some skeptics say show a cooling rather than warming, are variations that are repeated randomly in data as far back as 1880.

One statistician said that “cherry-picking” a micro-trend within a bigger trend is not the way to look at data.

This “blind” review of the data isn’t the only review that has shown obvious warming. Borenstein said that NOAA recently re-examined its data because of the recent “chatter” about cooling, and no cooling trend was found, and earlier this year, climate scientists in two peer-reviewed publications statistically analyzed recent years’ temperatures against claims of cooling and found them not valid.

For the full story, read Borenstein’s article here.

Source: Associated Press

October 15, 2009December 24, 2015 by Fraser Cain

Satellite Map

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There are thousands of satellites overhead in space right now, and many of them are being used to map every single square meter of planet Earth. And many of these images are being freely distributed on the Internet so you can access them through any browser. If you’re looking for a satellite map, there are many services out there that can help you out.

Probably the easiest and best place to start is with the Google Maps service from Google. This allows you to see a satellite map of the entire Earth. You can drag around the map to browse around the planet, and you can zoom out and in right down to the highest resolution images they have in their server. In many cases this means you can see your house, your yard, and even your car parked out in the street. You can also type in a specific address location and go straight there. There are street maps you can overlay or remove, you can get driving directions, and much more. And the Google Maps API has been made available by Google to other websites, so people are developing mashups that let you track running routes and find the nearest bathroom.

An even cooler satellite mapping service is Google Earth. Unlike Google Maps, you have to download Google Earth to your local PC, Mac or Linux machine (there’s even an iPhone version). Then you get this cool spinning 3-D version of the Earth. You can zoom out and in, type in a specific location address or geocode to find any spot on Earth. They also have a big library of additional layers that you can put over top, to see additional information mapped on the Earth. It’s well worth the download.

Another good service is TerraServer; they let you buy satellite maps if you want a nice printed version for your wall. If you don’t want to use Google, there are similar mapping tools from Microsoft and Yahoo.

We have written many articles about how satellites are being used to map the Earth. Here’s an article about how scientists use satellite photos to track penguin poop from space, and how Google’s maps had a satellite view of Obama’s inauguration.

We have also recorded an episode of Astronomy Cast all about Earth. Listen here, Episode 51: Planet Earth.

October 13, 2009December 24, 2015 by Fraser Cain

What is the Most Remote Place on Earth?

Have you had enough of kids, car alarms and the obnoxious laugh of your neighbor down the hall? You may find yourself wanting to get away from it all. If you aren’t lucky enough to have the magical nose of Sam Stephens to zap you into another dimension, you can visit Bouvet Island; an uninhabited, glacier clad island located between the southern tip of Africa and Antarctica. By all accounts, this is the remotest place on Earth, but if you don’t like the cold or have something against Norway, the county to which it belongs, take heart, you can always move to the comparatively burgeoning metropolis of Tristan da Cunha, a group of British, volcanic islands half way between South America and Africa. One of the islands in this group is actually called Inaccessible Island; and that’s saying something given its neighbors!

The most remote place on Earth can be defined as the landmass furthest from any other landmass and either inhabited or uninhabited. Since Tristan da Cunha is a group of islands, they can’t be defined as being furthest from another land mass, but taken as a whole, they tie with Bouvet Island as the most remote. The Tristan da Cunha group includes Ascension, Saint Helena and Tristan da Cunha itself which has a total population of 284. The islands are 2,816 km away from the nearest landmass.

What is Tristan da Cunha famous for, other than being hard to get to? Wideawake Airfield on Ascension Island was jointly owned by the US and British governments and used extensively during WWII, but then fell into disuse. In 1982, the British used Ascension Island as a staging base for the Falklands War. It’s famous also, for housing one of the 5 worldwide GPS ground antennae which you would no doubt, need to even get there!

Want more Earth extremes? Here’s an article about the hottest place on Earth, and here’s an article about the coldest place on Earth.

Here’s the guide to visiting Tristan da Cunha.

We have recorded an episode of Astronomy Cast all about Earth. Listen here, Episode 51: Earth.

October 6, 2009December 24, 2015 by Fraser Cain

Earth’s Layers For Kids

My son recently came back from a science day camp with one of the coolest things. It was a model of the Earth that he had created out of modeling clay. It showed the internal structure of the Earth, and because he built it, he was able to remember all of the layers of the Earth. Very cool. So here’s a good way to learn the Earth layers for kids.

To make your own, you need some modeling clay of different colors. You start by making a ball about 1.2 cm across. This represents the Earth’s inner core. Then you make a second ball about 3 cm across. This ball represents the Earth’s outer core. Then you make a third ball about 6 cm across. This ball represents the Earth’s mantle. And finally, you make some flattened pieces of clay that will be the Earth’s crust. To make it extra realistic, make some pieces blue and others green.

Take inner core and surround it with the outer core, and then surround that by the mantle. Cover the entire mantle with a thin layer of blue, and then put on some green continents on top of the blue.

If you’ve been really careful, you should be able to take a sharp knife and slice your Earth ball in half. You should be able to see the Earth’s layers inside, just like you’d see the real Earth’s layers. And you can see that the mantle is thicker underneath the Earth’s continents than it is under the oceans.

Here’s a link with more information from Purdue University so you can do the experiment yourself.

If you’re interested in teaching your children Earth science, here’s lots of information about volcanoes for kids.

We have also recorded a whole episode of Astronomy Cast just about Earth. Listen here, Episode 51: Earth.

October 6, 2009December 24, 2015 by Fraser Cain

How Big is Earth?

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Here’s a question: how big is Earth? Let’s take a look at how big our planet is.

First, the equatorial diameter of Earth is 12,756 km. In other words, if you dug a tunnel on the equator that went straight down and went right through the center of the Earth, it would be about 12,756 km long. Just for comparison, that’s about 1.9 times the diameter of Mars. And only .09% the diameter of Jupiter.

The volume of Earth is 1.08 x 10¹² km³. Written another way, that’s 1.08 trillion cubic kilometers of rock and metal. Again, it’s about 6.6 times more volume than Mars.

The surface area of Earth is 510,072,000 square kilometers. Of that, 29.2% is covered by land and 70.8% is covered by water. Just for comparison, that’s 3.5 times as much surface area as Mars.

The mass of Earth is 5.97 x 10²⁴ kg. Here that is written out: 5,970,000,000,000,000,000,000,000 kg. Yeah, that’s a really big number. And yet, it’s only 0.3% the mass of Jupiter (and Jupiter is mostly lightweight hydrogen).

We have written many articles about Earth for Universe Today. Here’s an article about how fast Earth rotates, and here’s an article about Earth’s magnetic field.

You can learn more about Earth from NASA’s Earth Observatory, as well as NASA’s Solar System Exploration Guide.

We have also recorded an entire episode of Astronomy Cast that’s just about Earth. Listen here, Episode 51: Earth.

September 24, 2009December 24, 2015 by Fraser Cain

Tsunami Pictures

Tsunamis are some of the most devastating natural disasters. The recent Boxing Day Tsunami was generated by an enormous earthquake off the coast of Indonesia on December 26, 2004. Coastlines in Asia were inundated with enormous tsunami surges, killing more than 200,000 people.

Here are some Tsunami pictures capture by satellite that show before and after images of the regions affected by the tsunami.

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This photograph shows the devastation that happened in Sri Lanka on December 26th. This picture was taken by the DigitalGlobe Quickbird satellite, and shows how the whole coastline was inundated with water.

Perhaps the most devastation from the tsunami occurred in Indonesia. This is an image of the town of Lhoknga, Indonesia. It was completely wiped off the map by the tsunami, except for the white mosque in the center of town.

This photograph, captured by NASA’s Terra satellite shows how the whole northwest coast of the island of Sumatra was hit hard by the tsunami. It looks like the vegetation was just scraped back from the edge of the island.

We have written many articles about the devastation from the 2004 tsunami. Here’s an article about how GPS could be used for a tsunami warning system.

You can get many more tsunami pictures from NASA from their Earth observation page.