February 6 – The Sky’s A Rockin’!

Today’s factismal: Nearly 42,000 meteorites hit the Earth every year.

Odds are, you’ve seen the really cool dashboard video of the meteor that light up the sky in Illinois and Wisconsin last night. Right now, we don’t know much about this particular meteor other than it was big and bright. We don’t know if it landed somewhere on Earth like the 42,000 other meteorites than come to ground each year or if it headed back out into space like the The Great Daylight Fireball of 1972. We’re not even sure where it came from – was it a piece of a comet or a chunk of an asteroid?

The Great Daylight Fireball of 1972 (Image courtesy and copyright James M. Baker)

The Great Daylight Fireball of 1972 (Image courtesy and copyright James M. Baker)

What we do know is that there will be nearly 70 different chunks of rock and ice that speed by the Earth in February alone! They’ll zoom past at distances ranging from just outside the atmosphere to 78 times the distance to the Moon. They range in size from the size of a tiny house (about 36 ft) to the size of a tiny village (about a mile across). These rocks are made up of chunks of comets and asteroids and even bits of Mars and the Moon that have been blasted into space by impacts from other chunks of rock!

A meteor streak across the Milky Way (My camera)

A meteor streak across the Milky Way
(My camera)

What is important about these chunks of rock is that they tell us how dynamic our Solar System is. Instead of being a dead old system with an orbit for everything and everything in its orbit, the Solar System is a dynamic, ever-changing system with the planets and comets and asteroids interacting to change orbits and thrown new stuff in new places. And they can provide us with samples from other planets and from the earliest formation of the system. Besides which, they are just plain pretty!

A meteorite as seen from above the atmosphere  (Image courtesy NASA/Ron Garan)

A meteorite as seen from above the atmosphere
(Image courtesy NASA/Ron Garan)

But the best thing about meteor is that you can help scientists learn more about them! If you download NASA’s Meteor Counter App (available for iPad, iPhone, and iWannaMeteor), then you’ll be able to send NASA scientists valuable information on the number of meteors that hit during the shower. They’ll then use that information to help us understand how likely it is that we’ll get hit. To learn more, go to NASA’s web site:
http://science.nasa.gov/science-news/science-at-nasa/2011/13dec_meteorcounter/

January 18 – Children Of The Sun

Today’s factismal: If you were born after 1977, you’ve never known a year that was cooler than average.

The climate numbers for 2016 are in and they are about what everyone expected; for the third year in a row, a new global temperature record was set. That makes 2016 the 40th year in a row that was warmer than average. Put another way, if you were born after 1977, the world has always been abnormally hot. Now part of those high temperatures in 2016 came from a lingering El Niño in the Pacific ocean, but El Niño comes and goes; it doesn’t last 40 years. And part of the high temperatures in 2016 came from a drop in volcanic activity which tends to lower temperature – but there have been some large eruptions in the past four decades. So why does the temperature keep going up?

The average global temperature has risen quite a bit in the past 136 years (Data courtesy NDC)

The average global temperature has risen quite a bit in the past 136 years; the blue line is the 20th century average global temperature
(Data courtesy NDC)

So why are we getting warmer? It is no secret; as a matter of fact, this very thing was predicted back in 1896 based on a discovery made in 1859. It is the CO2 that we are adding to the atmosphere. CO2 happens to block some of the “heat radiation” given off by the Earth. This is reabsorbed by the atmosphere, raising its temperature slightly. (Think of it as being like the interest given to you by a bank. You give them a dollar and every year they give you four cents more as interest. Over time, that interest builds up and so does your bank account.) Of course, lots of other factors come into play when you are talking about a planet , so the temperature change isn’t instantaneous and it has some wiggles in it. But overall, the pattern is clear: increasing CO2 increases temperature and changes climate.

The change from the 20th century average temperature. Blues are colder than average; oranges and reads are warmer than average. (Image courtesy NOAA)

The change from the 20th century average temperature. Blues are colder than average; oranges and reads are warmer than average.
(Image courtesy NOAA)

As a citizen scientist, there are two sets of things you can do. The first is to reduce the amount of energy you use; a nice benefit of this is that you also save money. For example, making sure that your tires are properly inflated will save you the equivalent of $0.10 per gallon and save the US the equivalent of 1.2 billion gallons of oil. Adding a layer of insulation to your water heater (like that blanket on your bed) will save you about $30 per year and save the US another 500 million gallons of oil. There are plenty of other way you can save money while saving the planet. But if you still want to do more, why not help record the changes that global warming is bringing to your neighborhood? Join iSeeChange and help them monitor how temperatures, weather, and other things are changing. To learn more, head to:
http://thealmanac.org/getinvolved.php

January 6 – Crack Of Doom

Today’s factismal: When the iceberg at the Larsen C Ice Shelf breaks off, it won’t directly raise sea levels.

By now, you have probably seen the news reports. There is an iceberg about the size of Delaware that is getting ready to break off of the Larsen C Ice Shelf in Antarctica.  Because the iceberg is already floating in the water, when it breaks off, it won’t raise the sea level. But it is still important because the same thing has already happened at Larsen B in 2002 and Larsen A in 1995 which tells us what will happen next – nothing good.

Glacier dynamics made simple

Glacier dynamics made simple

Ice shelves like Larsen C form when glaciers reach the sea and spread out. And glaciers form when snow piles up in the mountains and compresses into ice under its own weight. This compression creates ice so pure that it turns blue! The ice then slowly creeps downhill, like fudge sliding down the side of a scoop of ice cream. The ice actually moves in several layers, like sheets of paper sliding over each other; if you look at the top of a glacier, you can often see these layers in the lines of rocks that have fallen onto the ice. Once a glacier meets a deep enough body of water, it starts to float. The stress at the end of the glacier causes pieces to break off; this is called “calving” and the pieces are called “icebergs”. These bergs can range in size from smaller than a doghouse to larger than the state of Rhode Island! And when the bergs break off, another part of the glacier flows downhill to replace it, raising sea level just a little.

Larsen B breaks up after the loss of a large ice berg

Larsen B breaks up after the loss of a large ice berg
(Image courtesy NASA)

Right now, the Larsen C ice shelf is holding back the glaciers that are uphill. But when it breaks apart like Larsen B and Larsen A did, it will uncork enough ice to raise the sea level around the world by nearly a foot! If that doesn’t sound so bad, remember that the total sea level rise since 1870 was just seven inches. Of course, this won’t happen overnight; instead, it will take perhaps as much as twenty years. But while the sea level rise will be slow, it will also be unstoppable. Places such as New Orleans, New York City, and the Netherlands will all be challenged by rising sea levels.

Ice on the west side of Antarctica, where it is being lost in record amounts (My camera)

Ice on the west side of Antarctica, where it is being lost in record amounts
(My camera)

Today climatologists are working to puzzle out the climate changes that are caused by people (anthropogenic climate change) from those caused by other things (changes in the amount of sunlight, changes in the cloud cover, etc.). If you would like to help in this effort, then why not join Old Weather? You’ll read logs from sailing captains and help identify weather.
https://www.oldweather.org/

October 27 – Close Encounters Of The Worst Kind

Today’s factismal: Earth had at least 44 close encounters with an asteroid in this month alone!

It is, no fooling, a dangerous universe out there. There are gamma ray bursts and black holes and even some strange life forms out there. But perhaps the most amazing thing about the universe is how many close encounters the Earth has considering that space is mostly empty space. In the last month alone, NASA has recorded some 27 things that passed near enough to our orbit to be interesting (without the “Oh God, Oh God, we’re all going to die” part). NASA prefers to call these things “objects” because while most of them are just hunks of space rock heading for a fatal collision, some of them are actually bits of space junk headed back home.

A meteor enters the Earth's atmosphere, as seen from the ISS (Image courtesy NASA)

A meteor enters the Earth’s atmosphere, as seen from the ISS
(Image courtesy NASA)

And, of course, if we expand our definition of “asteroid” to include the bits of rock and dust and ice left in a comet’s wake, then there have been literally millions of “close encounters of the worst kind” in the past month. That’s because every day, more than 80,000 pounds of space debris hit the Earth’s atmosphere! If you look up at night, you’ll see those bits of rock and ice and dust; we call them meteors or shooting stars; if they are very big and very bright, then we call them “fireballs”.

The Great Daylight Fireball of 1972 (Image courtesy and copyright James M. Baker)

The Great Daylight Fireball of 1972 (Image courtesy and copyright James M. Baker)

Now those bits of debris are more than just pretty; they also tell us a lot about how the Solar System and the Earth formed. by keeping track of where they come from and how many there are, scientists can answer questions such as “Where are the comets?” and “How many asteroids hit the Earth?” and “Did an impact really kill off the dinosaurs?” But scientists can’t spend all of their time looking up at the sky; they’ve got data to work on and papers to write and blinking to do. So what are they to do?

Why, they’ll just ask for help. And that means asking you to spend some time looking at the sky each night. If you see a meteor, then just click on the NASA Meteor Counter app; the data you create will automatically be sent to NASA to help in their work! The app is available for free on iTunes and Google Play:
http://science.nasa.gov/science-news/science-at-nasa/2011/13dec_meteorcounter/

October 17 – Play Ball!

Today’s factismal: The first earthquake to be shown live on television happened in 1989.

You may have heard that there is a 72% chance that there will be a large earthquake near San Francisco sometime in the next thirty years. And that there is an  85% chance of a large earthquake on the San Andreas fault sometime in the next ten years. Experts think that it could cause as many as 1,800 deaths and as much as $200 billion in damage. But how can we know how much damage an earthquake will do? Simple – we know because we saw one happen, live on TV.

It was a balmy October evening in San Francisco. The Giants were competing with the Oakland A’s for the pennant, and the two teams were warming up in preparation for game three. As the television sports casters searched for something to add a little local color to the broadcast, they were given the greatest exclusive in history: an earthquake struck the area. And not some piddly little 4.0; this was a 6.9 Mb earthquake! As the anchors tried to describe what was happening, the world saw buildings shake, highways fall, and homes crumble into rubble.

A section of the collapsed highway (Image courtesy USGS)

A section of the collapsed highway
(Image courtesy USGS)

Amazingly, there were only 63 people killed in the earthquake (the 1905 temblor was about 30 times stronger and killed 3,000 people). Most of these happened in Oakland where a double-decker highway collapsed on itself. Interestingly, many credit the baseball game for the low fatality count. Because many people had left work early in order to watch the game, the highways were relatively uncrowded which meant that fewer people were hurt.

California is almost certain to have another large earthquake in the next three decades (Image courtesy SCEC)

California is almost certain to have another large earthquake in the next three decades
(Image courtesy SCEC)

But what is even more amazing is that the danger isn’t over. There is a 99.7% chance that some part of California will have another earthquake at least as powerful as this one in the next thirty years. So we know when the next big on will happen (soon); what we don’t know is where. And that’s where you can help. The USGS and Stanford University are developing a new type of distributed seismometer that uses the accelerometers in tablets, smartphones, and computers to provide more complete coverage of earthquakes; the data that this Quake Catcher Network gathers will then help them to narrow down when we can expect the next big one. If you’d like to take part, head over to:
http://qcn.stanford.edu/

October 5 – How Low Can You Go?

Today’s factismal: The most intense Atlantic hurricane ever recorded was Wilma, with a low pressure in the eye of just 882 mbar.

If you are a meteorologist, then 2005 is probably your favorite year. Over the course of the year, there were so many tropical storms that they ran out of names and had to resort to using Greek letters. Of the 28 storms that developed, a record high of 15 would go on to become hurricanes and seven of those would become major hurricanes. And none of those was more major than Wilma.

Wilma at peak strength (Image courtesy NASA)

Wilma at peak strength
(Image courtesy NASA)

Wilma started as a tropical depression off of Jamaica on October 15. Two days later, she had become a tropical storm. By the 18th, she was a full-fledged hurricane and showing no signs of getting any weaker. Indeed, where most hurricanes are big, ungainly monsters with large eyewalls (which often indicates a weaker storm), Wilma had a fairly compact eyewall just two miles across (the smallest known) and peak winds of 185 mph! Those factors combined to give Wilma the lowest known pressure of any hurricane at just 882 mbar; to put that in perspective, remember that normal air pressure at sea level is 1013 mbar. In effect, the center of Wilma was at the same air pressure as Denver!

Naturally, a storm this intense caused lots of damage. Wilma killed at least 62 people (mostly through flooding and landslides) and caused $29 billion dollars in damage. Many of the deaths happened because Wilma’s path was unusually unpredictable; she changed directions several times, making it harder to know where she would hit. What the meteorologists needed was more observations in order to give better predictions. What they needed was people like the members of the Citizen Weather Observer Program who send in reports about severe weather (and the other kind, too) that is then used to make better predictions. If you think that you’ve got what it takes to be a CWOP member, head over to:
http://wxqa.com/

September 2 – An Ill Wind

Today’s factismal: The lightning in a Category 1 hurricane has enough power to run a house for more than 300 years.

If you read the news today, you know that Hurricane Hermine has come aground in Florida. This ended the long dry spell for hurricanes damaging the US mainland (though Sandy was a hurricane in 2012, it had been downgraded to tropical storm before it came ashore); it was the first time in eleven years that the US mainland was hit. Of course, you don’t have to get a hurricane to get lots of storm damage, just ask the folks who sat through Sandy or Allison. Although it is too early for firm estimates, experts think that the damage from this storm will end up costing the US at least $5 billion.

A satellite image of Hurricane Sandy showing the temperature differences in the clouds (Image courtesy NASA)

A satellite image of Sandy showing the temperature differences in the clouds
(Image courtesy NASA)

So what causes all of that damage? The short answer is “energy”. Hurricanes are nature’s way of taking heat from the equator (where it is hot) and moving it to the poles (where it is cold). They do that by using the heat to evaporate water, which forms clouds, which forms storms. Because that heat also causes the air to expand, it drives winds which can drive water in the form of storm surge. Add it all together and you’ve got a lot of energy moving around, looking for something to break – like Florida.

Hurricane Hermine making landfall in Florida (Image courtesy NOAA)

Hurricane Hermine making landfall in Florida
(Image courtesy NOAA)

But how much of the storms energy is released by the different parts of a hurricane’s life cycle? Scientists have run the numbers and found that a hurricane typically releases about 0.002% of its energy as lightning. Now that may sound like small potatoes, but for a Category 1 hurricane, it works out to be enough energy to run a typical household for 360 years or so. (The trick is catching the lightning.) Storm surge is what does most of the damage along the coast and yet it is just 0.02% of the total energy of the hurricane. The winds in a hurricane are what creates that lightning and tornadoes and other exciting side-effects. They are understandably much more powerful; they represent about 4% of the total energy in a hurricane. Interestingly, the sheer weight of the water falling from the sky as rain and hail releases about as much energy as the wind does. Thus far we’ve accounted for about 9% of the energy in a hurricane with the lightning and the storm surge and the winds and the rain. Where is the rest?

Some of the effects of a hurricane (Image courtesy NOAA)

Some of the effects of a hurricane
(Image courtesy NOAA)

It is released high in the sky as water vapor condenses into rain drops and is known among meteorology wonks as the latent heat of vaporization (which is just a fancy was of saying “the heat stored {latent} in vapor”). As the water vapor is carried higher into the atmosphere by the rising air currents, conditions change so that water vapor is no longer stable and water is; this is what forms clouds (which are just raindrops that are too small to fall). When the water condenses, it gives back some of the energy that was used to turn it into a gas; the rest of the energy has gone into raising the vapor high into the sky and powering all of the other special effects.

But here’s the odd thing. Even though we can use satellites to track hurricanes and help people get out of their way, we still don’t know how reliable our satellite images of the clouds that make up hurricanes are. And that’s where you come in. NASA has a citizen science program called S’COOL that asks for people like you and me to tell them what clouds are out there when the satellites pass by. To participate, float on over to:
http://scool.larc.nasa.gov/rover.html