Question Your World: Can we live on another planet?

Somewhere around 4.5 billion years ago a gigantic ball of mass started to take shape and would eventually become where we all live.  So, the notion of a planet that can harbor life is not a strange one - after all, we happen to live on one.  Are there any other places that are similar? Can we live on another planet?

For the past 200,000 years or so humanity has been here on Earth.  In that time we've figured out how to use fire, harvest crops, change water streams, develop communities, embrace technology and learn about what happens beyond our tiny little cosmic stage.  Not bad for a new species!  Regardless, one thing we have yet to do is gain tactile proof of life existing anywhere else in the universe.

In order to search for life in other parts of the universe one needs to have a basic set of requirements. For example, the functionality of everything we know here on Earth can be traced back to our sun, so to look for other similar situations we must look at other stars (suns).  Well, we also know that the Earth is both rocky and has water.  Those are two more qualifications needed to search for similar conditions.  There's also the matter of temperature.  For example, Mercury is very hot, too hot to hold any life as we know it.  Similarly the moons of Pluto are far too cold for our taste.  Thus the position of the planet relative to its host star is a big deal as well.

Also, keep in mind, looking for planets is no easy task, the stars they orbit are so far away that we only see them as little dots of light in the night sky.  Scientists have tried various methods such as the wobble or transit methods to hone in on and fine tune their understanding of such faint and distant worlds. However, this incredibly complicated process has shown some remarkable data.  For example, in recent years we've gathered enough data to say that there's a really good chance that planets outnumber the stars in our universe.  NASA's official exoplanet list grows all the time and we're up to over 8.8 billion potentially trip-worthy planets in our Milky Way galaxy alone.  Regardless, it takes a lot of factors in just the right balance to allow for comparable conditions to our home here on Earth.

Our Earth is a good size, one that can use its gravitational pull to keep our atmosphere.  Aside from that, our distance from the sun allows for tolerable temperatures and the existence of liquid water.  Those two are very important aspects of planet-hunting.  As of now we're the only place in the known universe to be this size and this distance from our host star.  Well, we were the only place...

Recently, scientists used data from the Kepler Space Telescope and announced the first ever exoplanet discovered to be a similar size and a safe relative distance from their host star.  Kepler 186f is one of 5 planets that orbits its red dwarf star.  How far is it? About 500 light years from here - bring a book, it's a long trip.

So, we may not be able to go visit this place anytime soon, but this discovery is very important as it highlights the possibility of another life-harboring situation out there.  It has taken us around 200,000 years to get from the first time we opened our eyes to today where we can learn about the vast distant reaches of the cosmos.  The work that lays ahead for future generations could yield some remarkable findings on our universe, its creation and perhaps even a better understanding of who or what we are in the grand scheme of things.

Kepler 186f now joins the billions of other exoplanets discovered, but stands out with the distinction that it's the first exoplanet that meets a lot of the special qualifications needed to hold the most mysterious part of our universe, life.

QUESTION YOUR WORLD - How long is a light year?

So, how long is a light year...short answer: Long!!! long answer: about 5.9 trillion miles!!! That's how quickly light can traverse across space. So if you wanted to walk the distance of a light year you would need to be marching on your feet for about 168 million years!! For you to arrive at this moment, you would have had to start walking from the time when dinosaurs ruled the earth! Whew...better pack a few lunches for the calories you would have been using up! The speed at which light travels is still the fastest known speed in our universe.

On a related note, there sure are a lot of movies that make reference to this amazingly fast speed. Warp speed, Hyperspace, and Ludicrous speed are all references to the fastest known speed that we humans have been able to identify!

Check out more info on light year and big stellar distances here: Distance!


Also, Cool Cosmos has some pretty cool info about some of these huge distances and times!

Question Your World - How often does it thunder??

Thunder!! by ScienceMuseumofVA

How often does thunder happen on Earth?

A LOT!! 2,000 times per minute!! Also impressive is the amount of lightning that strikes the Earth every minute. 6,000 lightning strikes per minute! These bright flashes and loud rumbles of thunder are scary to some, but rain fall is a vital part of what makes Earth such a wonderful place for us to live on.

Here's an idea. Instead of being startled by the next thunder rumble you hear, you can use it to do a mini weather forecast.
Once you see lightning, just count the amount of seconds before you hear thunder. Then divide that number by 5.

Example:
(seconds between the lightning flash and hearing thunder) 10/ 5 = 2
The storm is 2 miles away from you!
That's enough time to grab an umbrella!

Thunder is pretty impressive stuff.

Question Your World - Stellar Headlines!

A lot of space related news has happened in the last month. Here are some of the highlights of what's happening out there...way out there.

Huge news from NASA. The MSL (Mars Science Laboratory) launched in late November and is expected to arrive on the Martian surface in August of 2012. This one ton robot will rove the planet looking for soil samples that show if Mars was or was not ever capable of holding life. This will be a huge step forward in researching the types of conditions in the universe that could or could not hold life! For more info on the MSL please go to http://mars.jpl.nasa.gov/msl/



In other news, the Voyager 1 satellite has left the solar system!!! That's right, this officially is the very first human made object to leave the solar system. This probe is about 10 BILLION miles away from Earth right now and is, amazingly, still communicating with us. Voyager 1 was launched in 1977...pretty far out!

Lastly, big big big news from 600 light years away. Kepler 22b has been confirmed as an "Earth-like" planet. This newly discovered planet is 600 light years away, about 2.5 times larger than Earth, and orbits a star very similar to our own sun. Scientists think that the average temprature on Kepler 22b is about 70 degrees, how lovely. More on this discovery can be found right here, http://en.wikipedia.org/wiki/Kepler-22b





Happy Holidays and we'll catch up with more Stellar Headlines next month!

Question Your World - What's NASA ever done for me?

20111130 NASAinventions by ScienceMuseumofVA

Other than blasting people into space and taking photos of far off distant worlds, NASA has contributed a lot to our day-to-day lives also. Check out this page for more info on what NASA's done to help you sleep, clean, and live a little easier. NASA Inventions!

Thank you NASA!

Neptune

A lot has been discovered about Neptune since its initial sighting in 1846. The Voyager 2 spacecraft, on Aug 25, 1989, did a fly by of this blue celestial giant and sent back some photos and other data that has helped the science community understand more about the last planet on the block. Here are some interesting factoids about Neptune:
8th Planet from the sun
Gaseous Giant
13 Moons
Named after the Roman god of the oceans, Neptune
Has rings…just like all the other gaseous giants
2.68 BILLION miles from Earth at its closest point in orbit
60,190 Earth days (164.8 Earth years) for Neptune to orbit the sun once!!
Looks cool…because it is VERY cool…as in cold -330F (72 Kelvin)…(-201 C for the non-US friends of the Science Museum of Virginia)…brrr!
After 2006's demotion of Pluto, this blue gaseous giant became the last official planet in our solar system.

Scheila Sports a Plume

Meet Scheila and her friends:

http://www.nasa.gov/topics/universe/features/asteroid-collision.html

An asteroid named Scheila lives in the asteroid belt between Mars and Jupiter with millions of other asteroids.  Scheila is about 70 miles across and completes her orbit around the sun every five years.  Late last year, astronomers noticed Scheila had gotten noticeably brighter and was adorned with plumes.  After studying data from the Hubble Space Telescope and Swift satellite, they determined Scheila had collided with one of her fellow asteroids at 11,000 miles per hour (ouch!).  The plumes made Scheila appear comet-like and were most likely small particles of dust from Scheila’s surface.  In two months, the dust had dissipated and Scheila was back to normal.  Thanks to Hubble and Swift, astronomers could study the collision before all evidence of it disappeared, allowing them a peek inside an asteroid.  Now I wonder what Scheila thought of that…

Question of the Week

Space, the final frontier...

Today at 4:50 pm, space shuttle Discovery will blast off on its final mission into space.  On board Discovery are six astronauts, the Permanent Multipurpose Module which will become sort of a storage closet for the space station, and Robonaut 2, the first dextrous humanoid robot to go into space. Robonaut 2 will test his ability to operate in zero gravity and will eventually become an astronaut's helper.


If astronauts received frequent flyer miles while in space, how many would they receive on a typical shuttle mission?

Answer:  The typical shuttle mission orbits the Earth 250 times - about 6.6 million frequent flyer miles!

Question of the Week

Today in Richmond, we are experiencing a messy and somewhat hazardous mix of snow, sleet and freezing rain. 

Do you know what atmospheric conditions cause each kind of frozen precipitation?



Answer:  Winter precipitation types generally depend on the vertical temperature profile of the atmosphere.

• Snow falls when the temperature of the entire depth of the atmosphere from the cloud to the ground is below freezing (32 F or 0 C).
• Sleet falls when there is a fairly shallow layer of warmer air (above freezing) between the cloud and the ground but the temperature at the ground is below freezing.  Snow falls from the cloud, then partially melts in the warmer layer and then refreezes in the colder layer near the surface, forming pellets of ice.
• Freezing rain falls when there is a deep layer of warmer air (above freezing) but the temperature is below freezing at the ground.  Snow falls from the cloud, melts completely in the warm layer and then refreezes either just before hitting the ground or on contact with the cold surface.

Odd Science 2010

Besides highly publicized science stories of 2010 (Gulf oil spill, Chilean miner rescue, bedbugs, etc.), there were some intriguing and somewhat odd science stories:

1. You think like a worm – The human brain’s center of deep thought is curiously similar to a clump of neurons inside the head of the lowly ragworm. So similar, in fact, that ragworms, which evolved 600 million years ago, probably share a common ancestor with us humans. Hmmm…

2. The shrinking moon – Lunar geologists have found cliff-like scarps on the moon that they believe formed as the moon lost heat and contracted. But don’t panic – the moon’s radius has only shrunk a few hundred feet in the last billion years. Considering its small size, though (its diameter is less than the distance from Washington, DC to San Francisco), let’s hope it doesn’t shrink too much more…

3. Dinosaurs in color – Sinosauropteryx, a chicken-size dinosaur, and was covered with spiny hair, ate meat and walked on its hind legs. Scientists examining the hair bristles under a powerful microscope discovered its tail contained melanosomes, color-bearing cell parts found in modern birds. And what color was it? Sinosauropteryx sported a chestnut and white striped tail! Cool!

4. Bowerbirds exaggerate – Male bowerbirds lure their mates with large collections of stones, shells, bones and other trinkets, even some man-made ones. Their display is usually arranged from largest to smallest, creating an optical illusion. As the female approaches, the display area appears smaller, making the male in the center appear bigger. Clever guy!

5. Rubik’s Cube decoded – Have you ever tried to solve a Rubik’s Cube? How many moves did it take you? Mathematicians have discovered that out of the 43,252,003,274,489,856,000 possible starting positions, you should never have to make more than 20 moves to solve the puzzle. Can you do it?

These 5 are just a taste; Discover magazine's current issue includes the 100 Top Stories of 2010.

http://discovermagazine.com/photos/100-top-science-stories-of-2010

Is It Winter Yet? Maybe, Maybe Not…

Snow frozen onto a tree in Germany.
Photo courtesy of Wikipedia

Tuesday, December 21, is the Winter Solstice and usually considered the first day of winter. However, meteorological winter is already here! So what’s the deal? Well, the definition of winter depends on whom you ask.

A meteorologist defines winter as the three coldest months of the year: December, January and February. An astronomer defines winter as the three months between the Winter Solstice (December 21 or 22) and the Spring or Vernal Equinox (March 20 or 21). What’s the difference?

The definition of meteorological winter is fairly straightforward. Climatologically-speaking, the three coldest months of the year are December, January and February in the Northern Hemisphere. Therefore, meteorological winter begins on December 1 and ends on February 28 (or 29). In the Southern Hemisphere, the seasons are reversed, meaning if you lived in Rio or Buenos Aires, summer would begin in December and winter would begin in June.

Astronomical winter begins on the Winter Solstice, the shortest day of the year. The Earth has seasons and variable daylight hours because its axis is tilted 23.5° relative to its orbit around the sun. Winter in the Northern Hemisphere occurs when the northern half of the planet is tilted away from the sun. This tilt causes sun’s energy to be weaker on the Earth’s surface because:

• The sun shines on the Earth’s surface at an oblique angle.
• The sun’s energy is spread out over a larger area, diluting its strength. 
• The sun’s rays travel through more atmosphere before they reach the surface. 
• Days are shorter so there is less time for the sun to heat the surface. 

Less energy from the sun on the Earth’s surface means colder temperatures in the atmosphere – so winter arrives. For more information, check out last year’s blog about the Winter Solstice: http://sciencemuseumofvirginia.blogspot.com/2009/12/winter-solstice.html

Here are some questions for you to ponder:

• If the Earth’s axis had no tilt, would we have seasons? 
• If the tilt was at a greater angle, what would our seasons be like? 
• Do you think other planets in the solar system have seasons too? 
• How did Earth’s axis get tilted in the first place?

Watch the Sky Show: the Leonids

Want to wish upon a falling star? This is the week - the Leonid Meteor Shower peaks tomorrow. Earth is currently passing through the “tail” of Comet Tempel-Tuttle. Often called a “dirty snowball,” a comet usually orbits the sun in an elliptical orbit. The comet’s nucleus, consisting mostly of ice and dust, heats as it approaches the sun. Particles begin to stream out behind it and form the comet’s “tail.” As Earth passes through this “tail” the particles collide with the atmosphere and we see a meteor shower.


Best viewing of the Leonids will be just before dawn on Wednesday, November 17 in the eastern sky (see above map). Scientists estimate this year’s show will produce 15 to 20 meteors per hour (a sighting about every 4 or 5 minutes). Meteor showers are notoriously difficult to predict - there may be many more or there may be less.

The waxing gibbous moon will set in Richmond about 4 hours before sunrise tomorrow, so the bright light of the moon will not inhibit viewing in the early morning hours. However, clouds and showers may accompany a cold frontal passage in the Richmond area early Wednesday morning. Let’s hope we get lucky and the skies clear before dawn. But there is another chance - the Leonids may be visible just before dawn on Thursday morning also.

A few tips for best viewing:

 • Find an open area away from city lights with no tall buildings or trees in the eastern sky.
 • Take some friends – it’s always more fun with someone along.
 • Let your eyes relax and look all around - binoculars not required. Actually, your eyes will find the meteors  better without binoculars because they have a broader range of vision.
 • Take some equipment for maximum enjoyment:
        o Lawn chair – be comfortable; kick back and relax.
        o Blankets or sleeping bag – bundle up; it will be chilly (50’s).
        o Hot coffee or tea in a thermos.
 • Binoculars might be useful for observing fireballs, unusually bright meteors that leave an incandescent streak lasting as long as a few minutes. Winds in the upper atmosphere will bend and distort the streak; binoculars will give you a close-up view.

Interesting fact (from http://www.space.com/ ): When a comet takes 33 years to go around the Sun, it goes way out there and tends to get lost. Comet Tempel-Tuttle gets lost a lot. It also gets found now and then. Tempel-Tuttle was "discovered" by William Tempel in late 1865 and independently by Horace Tuttle in early 1866. Nobody saw Tempel-Tuttle again for almost 100 years (1965). Then on March 4, 1997, armed with great orbital data, Karen Meech, Olivier Hainaut and James Bauer at the University of Hawaii "recovered" the comet yet again. Tempel-Tuttle will next return to the inner solar system in 2031.

For more information, go to http://www.space.com/.  Star map credit: Stardate.

Thoughts on Virginia’s Goodwill Moon Rock

Thirty-eight years ago I stood with my younger brother on a shoreline near midnight looking eastward across 12 miles of quiet, dark water at the brilliant jewel on the far horizon. A million people lined the beaches as far as we could see. In the distance xenon arc lights crossed upon the largest craft ever to carry humans. The thunderstorm that had earlier sent tendrils of blue and orange lightning beyond the gantry had since moved far out to sea.

At the final countdown the night burst into a blaze of silent light and the sky glowed crimson to the far horizon behind us. A full minute would pass before the sound hit us, a deep shattering moan shaking our rib cages, the trees and cars. The last Apollo Saturn V rocket lifted with the inexorably slow climb of a freight elevator. Our 8mm film would show its three stages burning successively into orbit in the clear, beautiful night.


In that minute before the rocket's sound reached us, the collective expression of the human spirit, in all its aspirations, went up from the multitude on the beaches. The shouting, weeping, praying and cheering of a million voices blended into a roar that lifted with the three on their way to the moon.

Human space flight inspires in ways that more cost-effective robot probes do not. This experience fueled my drive to study physics.

These are my thoughts this summer as I had the challenge of gathering and arranging information and images about the Apollo missions to the moon. The result of this curatorial work would become part of the exciting, new installation and display of the museum’s Apollo 17 moon rock -- in a new setting that directs the visitor’s attention to one of the rarest objects on Earth.

As I worked in the Stardome room (at the north end of the Main Concourse) with the moon rock case nearby, I thought about the coincidence that I had witnessed the launch of that very mission in December of 1972.

From that mission Harrison Schmitt brought back 242 pounds of lunar material, including the Goodwill Rock that provided the plaque-mounted specimens given to every U.S. state and territory and every nation on earth in 1973.


Apollo science is still alive in some ways today. Three Apollo missions left retro-reflector arrays on the moon to bounce laser light back to Earth. These arrays allow scientists to measure daily the distance and the motion of the moon away from Earth, at about an inch and a half a year.


Another final milestone approaches. The last and final Space Shuttle flight (the 134th ) has been authorized for launch next summer. Next August the NASA will leave manned space flight to others, possibly for decades. The Space Shuttle is the most complex thing ever built, with 2 ½ million parts and 230 miles of wiring. These difficult economic times make it hard to justify the extravagance of human space exploration.


We have, however, a rich and long history of unmanned space probes. Our 1970s launches of Pioneer 10 and 11, and Voyager 1 and 2 yielded a treasure trove of dazzling images of the outer solar system and are now far beyond it. They carry gold plaques and phonograph records explaining the culture of the species from Earth that sent them.


And we continue to roll out ever more sophisticated unmanned spacecraft. A long range probe is on its way to Pluto. A replacement for the Hubble Space Telescope is under construction, with 15 times Hubble’s light gathering ability. Other orbiting telescopes are looking for extraterrestrial planets. Further unmanned probes are planned for Mars and the moon. Others may explore oceans of salt water beneath the ice on Europa and Enceladus, moons of Jupiter and Saturn.


Oh, yes. We actually did go to the moon. Had we not gone, telescopes all over the Earth would not have recorded, as they did, the flights and the return journeys. Russia and the rest of the world would have called our bluff. Indeed, Russia cancelled its manned moon program largely because of the verified success of our Apollo program.


So, I return in my thoughts to the museum’s Apollo 17 moon rock, a small, three billion year-old memento of a trip made 38 years ago.

David Hagan
Museum Scientist
Science Museum of Virginia

Remember Hurricane Andrew?

As Hurricane Danielle churns far out in the Atlantic, I am reminded of another hurricane that made landfall on this day…

On August 24, 1992, a small but extremely intense Hurricane Andrew slammed into South Florida. Andrew made landfall as a Category 5 hurricane, the 3rd most intense landfalling US hurricane and the 1st in total estimated US property damage at the time. (Katrina eclipsed it in both intensity and damage in 2005.) Andrew hit the highly populated Miami area after a 27-year lull in hurricane activity in the Atlantic basin. During the period between 1965 and 1992, only 2 hurricanes of any significance made landfall in Florida, both in the panhandle. At the same time, the coast around Miami had experienced unprecedented development, populated largely by residents from the Northeast who had no experience with Florida’s history of violent hurricanes. As a result, South Florida was devastated. Damage was extensive, estimated at about $30 billion. Fifteen people lost their lives directly due to the hurricane and another 25 by more indirect means.

Yes, hurricanes can be devastating and deadly; however, I have always been fascinated by them. (I confess - I am a weather nut.) Don’t get me wrong – I do not want them to come ashore and destroy homes and lives; however, watching them develop from a messy disorganized cluster of clouds into a perfect spiral inspires me to wonder at the beauty and power of nature. But I do prefer that all this beauty and power stay well off-shore…

Happy Birthday, Voyager 2!

For an incredible 33 years, Voyager 2 has been our eyes of discovery in the outer solar system and beyond. This venerable spacecraft has been in continuous operation more than 12,000 days, sending us compelling photos and information about the gas giants of the solar system: Jupiter, Saturn, Uranus and Neptune. Now headed into interstellar space beyond the solar system, the spacecraft is still transmitting invaluable data about the solar wind and deep space beyond the planets.

On August 20, 1977, Voyager 2 blasted off from Cape Canaveral, FL on a mission to the giant planets of the solar system. Its sister spacecraft, Voyager 1, was launched a few days later on September 5. Both original missions were intended to study just Jupiter and Saturn. However, both continued sending data beyond those planets, and thanks to these intrepid spacecraft, we have now had a close encounter with every planet in the solar system. (Pluto is now called a “plutoid” and is no longer considered a planet.)

(Just think, the computers on these spacecraft were made in the 1970’s and they are still working! Pretty remarkable, huh?)

Here are a few fast facts about the Voyager mission:

• Explored all giant planets of the outer solar system
• Explored their 48 moons and unique ring systems
• Closest approach to Jupiter - 1979
• Closest approach to Saturn - 1980 (Voyager 1); 1981 (Voyager 2)
• Closest approach to Uranus – 1986 (Voyager 2)
• Closest approach to Neptune – 1989 (Voyager 2)
• Carry a golden record with a greeting from Earth
• Now the most distant human-made object in space (Voyager 1)
• Distance from sun - 17 billion km (Voyager 1); 14 billion km (Voyager 2)
• Signal from Earth takes over 12 hours to reach spacecraft
• Crossed termination shock, where solar wind slows abruptly, in 2004 (Voyager 1); 2007 (Voyager 2)
• May have reached or will soon reach Heliopause or entry into interstellar space
• Currently, 5 teams investigating: Magnetic fields, Low energy charged particles, Cosmic rays, Plasma (Voyager 2), Plasma waves
• May continue to operate and send data until around 2020

Long-lived Voyager has been documented often in fiction and pop culture (remember “V’ger” in the Star Trek movie?). So Happy Birthday, Voyager! May you live long and prosper!

Eyjafjallajökull: “the little volcano that could”

Eyjafjallajökull? Can you pronounce it? Apparently, it’s: “AY-uh-fyat-luh-YOE-kuutl(-uh).” If that helps, good for you! Even after hearing an Iceland native pronounce it, I still can’t manage to wrap my tongue around that many syllables.
First, a little geography – Iceland, sometimes called the land of fire and ice, is an island in the North Atlantic Ocean between Greenland and northern Europe. It’s about the size of Virginia with a population slightly less than that of Virginia Beach. At 65°N latitude, the subpolar climate would be brutally cold if the Gulf Stream ocean current did not moderate temperatures somewhat; Iceland's average July high is around 57°F and its average January high is around 34°F.
So why does Iceland have so many active volcanoes? Two factors. First, the island is bisected by the Mid-Atlantic Ridge, the boundary between the North American plate and the Eurasian plate. The two plates diverge along this boundary, forming new crust along the ridge; therefore, Iceland is continually getting bigger. In addition, geologists believe Iceland is over a hot spot, an area of rising lava below the earth’s crust. Hot spots often breed volcanoes and sometimes new islands; the islands of Hawaii were formed over a hot spot in the Pacific. However, the Hawaiian Islands are in the middle of a drifting tectonic plate, rather than between plates, so an island in the Hawaiian chain will eventually drift away from the hot spot and a new island will begin to form over the hot spot. As long as Iceland straddles the mid-ocean ridge and the hot spot remains under the ridge, Iceland will remain one of the most active volcanic regions on earth.
Eyjafjallajökull may have cooled slightly, but today’s strong tremors indicate that the eruption is not over yet. Also scientists are concerned that Katla, a much bigger and more active volcano, may erupt next. Past evidence indicates that when Eyjafjallajökull erupts, Katla follows. Katla’s eruption could be much more explosive, and Katla is overdue. Explosive eruptions often send ash and other matter into the upper atmosphere where they stay for long periods often causing dramatic global climate change.
Now that Eyjafjallajökull has calmed somewhat, we can take a look at the impact and subsequent ripple effect this eruption caused around the globe. The most obvious: Eyjafjallajökull’s ash cloud grounded planes all over Europe, inconveniencing travelers who were stranded in airports for days and costing the airline industry over $1 billion in lost revenue. In addition, the eruption affected the economy and citizens of countries near and not-so-near the island of Iceland.
Kenya - thousands of laborers are out of work; flowers and produce cannot be shipped to Europe. 10 million flowers, mostly roses, have been thrown away.
Ghana – pineapple and pawpaw farmers’ incomes are suffering due to lack of refrigeration at Ghana’s capital airport.
Japan – Nissan stopped production at two of its plants on Wednesday because they ran out of tire pressure sensors due in from Ireland.
Australia – a family from Britain saved for two years to make a trip to Australia, then the hotel more than doubled the rates (because they could). The frustrated family moved to a hostel.
Iraq and Afghanistan – medical evacuation flights are taking up to 8 hours longer than usual because they cannot fly back to the US out of Germany but instead must fly out of Spain.
United States – the airline slowdown cost the US economy $650 million and affected about 6000 American jobs. BMW reduced production at its Spartanburg, SC plant due to lack of supplies from Germany. Brides in New York had no Dutch flowers (tulips, peonies, or daffodils) for their weddings. Marathoner David Gray missed his second consecutive Boston marathon while stuck in a hotel in Brussels (the first was due to injury).
If Katla erupts, the impacts could be even greater…

Thanks to CBS News for the international anecdotes and to the Associated Press for the photo.
For more info, go to http://www.guardian.co.uk/environment/blog/2010/apr/20/iceland-volcano-your-questions-answered
And for great volcano pix, go to - http://www.boston.com/bigpicture/2010/04/icelands_disruptive_volcano.html

Why are we having so many earthquakes?

Another earthquake – this time in Turkey. Earthquakes are certainly in the news. Fortunately, earthquakes are not a frequent occurrence in Virginia, but they do happen. Do you remember the one on December 9, 2003? It measured 4.5 on the Richter scale; its epicenter was just south of the James River in Powhatan County. I remember it well; it was quite an experience!
With all the recent reported earthquakes, you might wonder if they are related; that is, could the earthquake in Haiti cause the one in Chile, which might then cause the one in Turkey and so on? Here are some frequently-asked earthquake questions and their “myth-busting” answers:
1. Why are we having so many earthquakes?
Although it may seem like it, we are not having more earthquakes than usual. Earthquakes do occur in clusters, though, but clusters are predicted by statistics and do not mean the quakes are related. (Also, there are long periods when earthquakes are not in the news, but that is not considered unusual.) Several factors make it appear earthquake frequency has increased:
(a) Better reporting – in 1931 there were 350 stations reporting earthquakes; now there are 4000. Current stations locate an average of 50 quakes per day. In general, there are about 18 major quakes per year (7.0-7.9) and one great one (8.0+).
(b) Increasing global population makes for more casualties and thus more reporting.
(c) Better communication around the globe allows us to know about earthquakes quickly so it’s timely and newsworthy.
2. Can scientists predict earthquakes?
Unfortunately, they do not know how. However, using scientific data, they can calculate the probability one will strike in the future.
3. Can animals predict earthquakes?
From the days of ancient Greece, there have been reports of animals behaving strangely just before an earthquake. Scientists have investigated and cannot find consistent and reliable animal behavior prior to an earthquake.
4. Is there a particular time of day that earthquakes tend to occur? Do they occur more often at certain time of the month or year?
Earthquakes are equally probable at all times of the day, month or year.
5. Can the ground open up during an earthquake?
In an earthquake, the earth moves along a fault not perpendicular to it, so the ground would not open up. If it did, there would be no friction, thus no quake. Landslides and other ground failures caused by earthquakes can cause crevasses and depressions to form, however.
6. Will California eventually fall into the ocean?
No. The Pacific Plate runs into the North American Plate at the San Andreas Fault. The Pacific Plate is moving northwest relative to the North American Plate at a rate of 46 mm/year (about the rate your fingernails grow). California will not fall into the ocean, but LA may one day have a very cold climate – it is heading toward Alaska.
The above information came from the US Geological Survey. Want to know more? Go to http://earthquake.usgs.gov/earthquakes.

Winter Solstice *

At 12:47 pm today, December 21, 2009, winter begins in the Northern Hemisphere. The first day of winter is called the Winter Solstice; likewise, the first day of summer is the Summer Solstice. The word solstice is derived from Latin and means “sun standing still.” On these two days of the year, the sun’s apparent position in the sky has reached its most southern or northern extreme. Today there will only be 9 hours and 33 minutes of daylight in Richmond, but tomorrow the number of daylight hours will once again begin to increase.
The solstices and the seasons occur because the Earth’s axis is tilted 23.5° relative to its plane of revolution around the sun (see illustration). In the Northern Hemisphere winter, the northern half of the globe is tilted away from the sun; therefore, the sun is low in the sky giving us shorter days and longer nights. At this oblique angle, the sun’s energy is spread over a larger area of the Earth’s surface and thus is weaker than if it was hitting the surface more directly. Also, the sun’s rays must travel through more atmosphere before they reach the Earth’s surface, and some of the solar energy is reflected back into space. In addition, there are less daylight hours to warm the Earth. With all these factors combined, is it any wonder that we have winter weather?
Contrary to what many believe, the Earth is not farther from the sun during the winter. Actually, the Earth is almost at its closest point to the sun at the time of the northern hemisphere’s Winter Solstice. This variation in the Earth’s distance from the sun is small and does not greatly affect the weather; however it does slightly modify the severity of the Northern Hemisphere winters and summers.
While we are experiencing winter, the southern hemisphere is experiencing summer. Our Winter Solstice is the southern hemisphere’s Summer Solstice. If you lived in Rio or Sydney, the winter months would be June through August and the summer months would be December through February.
Here’s some food for thought: what if the Earth’s axis was not tilted? Would we have seasons? What if the axis was tilted more than 23.5°? Or less than 23.5°? What would our seasons be like? How did the Earth get its tilt? All the planets in our solar system have some axial tilt, but they are all different. Why?

*Technical difficulties delayed the posting of this blog entry.

Tis the Season… for Nor’easters?

What will this winter be like? If the current weather pattern continues, the East Coast will certainly be stormy. Friday night through Saturday (December 18-19), Virginia experienced yet another intense Nor’easter (see blog of November 12). This one dumped huge amounts of snow over the central and western parts of the state.
Whether Virginia gets rain or snow from a winter Nor’easter depends largely on the track of the storm. A more westerly inland track will pull in warmer ocean air and Virginia will usually get rain. If the center of the storm stays just off the coast, cold air is often pulled in behind the storm and Virginia can get snow, sometimes lots of it. Nor’easters can intensify to hurricane strength and bring extremely high winds, coastal flooding, beach erosion, and heavy rain or snow to the mid-Atlantic and Northeast states. In the satellite picture above, note the hurricane-like eye in the center of this intense storm.
In addition to the heavy snow and gusty winds, this storm also included thundersnow. Thundersnow occurs only rarely and is basically a winter thunderstorm with falling snow instead of the usual rain. The lightning is nearly blinding due to its reflection off the white snowflakes, and the sound of the thunder is acoustically suppressed by the snowfall. Normally, thunder can be heard many kilometers away from a thunderstorm, but the thunder from thundersnow can only be heard 2 or 3 kilometers away. We had thundersnow at my house just after midnight on the 19th with at least two very bright lightning strikes and accompanying thunder.
How much snow did you get from this storm? I had 1 foot at my house in Midlothian, about 15 miles west of Richmond.

What do you think of this storm? Virginia and much of the mid-Atlantic coast is experiencing a Nor'easter today: heavy rain, gale force winds, coastal flooding, downed trees, power outages, beach erosion... well, you catch my drift. The storm gets the name Nor'easter because the wind blows primarily from the northeast. A Nor'easter is a cyclone, or low pressure system, whose center stays just off the coast. Nor'easters can have winds of hurricane force and can sometimes intensify very quickly.

This particular storm began as hurricane Ida, a tropical cyclone. Tropical cyclones form over very warm ocean waters and get their energy from the release of latent heat when water vapor condenses into water droplets. They have a warm core, no fronts associated with them and have their strongest winds near the surface. Extra-tropical cyclones get their energy from temperature gradients, such as when a warm air mass collides with a cold air mass. They have a cold core, usually both warm and cold fronts associated with them and have their strongest winds in the upper atmosphere. Tropical cyclones can "morph" into extra-tropical cyclones and vice versa, although the latter is more rare.

Many of the worst blizzards in the Northeast US were Nor’easters. Extreme cold often follows in the wake of a Nor’easter, due to cold air being dragged out of Canada by strong northwest winds behind the storm.

The book and movie The Perfect Storm was about an actual 1991 Nor’easter that absorbed Hurricane Grace and later moved far enough south to become a hurricane itself. Unlike most hurricanes, this storm was never named, and New Englanders still refer to it as the No-Name storm.

Did you know surfers love Nor'easters? Waves can be very high during these storms. Even though it is cold, they just don their wet suits and head out.

Do you have a Nor'easter experience? Here's one of mine: my brother had rented a house in the Outer Banks one spring when a Nor'easter hit. Large quantities of sand blew onto and covered the road near Rodanthe. The highway department managed to open a one-lane track for cars to pass, necessitating a wait for oncoming traffic to clear. In the 30 minutes we were waiting, huge hunks of wet sand were raining down on our car. By the time we arrived at the house, the entire left side of the car was caked in sand. That night the house rocked us like we were in a cradle. It was an experience I will never forget.