Monday, March 21, 2011

Sunday, March 20, 2011

Messenger Enters Mercury’s Orbit

On Thursday, March 18th the Messenger unmanned spacecraft entered Mercury’s orbit.  The last time a spacecraft sent to Mercury was Mariner 10 in 1974 and at that time Mariner 10 was only able to photograph 75% of Mercury’s surface.  Messenger will orbit Mercury for one year and will map the entire surface including color photographs.  On April 4th, the science portion of the mission will begin as NASA scientists and engineers will begin getting data to interpret from Mercury’s surface.  Over the next few months we should be getting some never before seen images of Mercury.  NASA has a website dedicated Messenger webpage with updates on the mission and photographs.
Weather on Mercury today: very hot (again)
Mercury is a strange, small planet.  Mercury is a bit smaller than Earth’s moon.  Mercury takes 88 Earth days to circle the sun – this is the length of its year.  Oddly, one day on Mercury is equal to 59 days on Earth.  It takes Mercury 1,407 hours to rotate 360o.  Mercury does not have an atmosphere to retain heat so its temperatures range from 800 oF in the day to -279 oF at night.  Mercury is a dense planet and its core is 65% iron in a form that is not normally seen on Earth.  This composition is unexpected in such a small planet.  Some scientists theorize that Mercury could have been a larger planet at one time and some sort of massive collision caused it to lose its outer layers.  The elemental composition of Mercury is one of the topics that is being studied in the Messenger mission.  You can learn more about Mercury on NASA’s Mercury page.

Friday, March 18, 2011

Angolatitan Adamastor Dinosaur -- Eaten by Sharks?

This week scientists announced the discovery of a new dinosaur species that they have named Angolatitan adamastor.  The fossils were found in Angola, a country in Western Africa and are about 90 million years old.  The fossils belong to a kind of long-necked, plant-eating sauropod.  The name Angolatitan adamastor means “Angolan Giant”.
Scientists theorize that the Angolatitan adamastor may have been eaten by sharks.  The fossils of the dinosaur were found in the bed of an ancient lake along with fish and shark teeth.  The Angolatitan adamstor may have been swept offshore into the water where hungry sharks attacked and ate it.  Those were some hungry sharks!

Thursday, March 17, 2011

Why Do Four-Leaf Clovers Have Four Leaves?

Finding a four-leaf clover is lucky, but how lucky?  Scientists have estimated that there is one four-leaf clover for every 10,000 three-leaf clovers making them very rare.  Four-leaf clovers occur in nature because of their genes.
All living things have genes.  In a simple definition, a gene is the basic unit of heredity.  For example, my daughter has blue eyes because of her genes which she received from her Dad and I.  Over the past 15 years, scientists have been able to identify many genes not only in people, but also in plants and animals.  In 2010, researchers led by Professor Wayne Parrott at the University of Georgia found the gene for the four-leaf trait in clover.  This is a recessive gene meaning that it happens less frequently.  Additionally, this gene is influenced by the environment.  For example, clover growing at different temperatures or subject to different amounts of light with the same genes can grow differently with three or more leafs.
Clovers are associated with St. Patrick’s Day because legend has it that St. Patrick used the three-leaf clover to teach Christianity in Ireland.  Each of the leaves represented the Father, Son, and the Holy Spirit.    In modern times, people believe that the leaves on a four leaf clover represent hope, faith, love, and luck. 
Happy St. Patrick’s Day!
Here is the link to the paper by Professor Parrott and his research team on leaf traits in clover.

Wednesday, March 16, 2011

Super Moon on Saturday, March 19th!

On Saturday March 19th we will see a really big full Moon.  In fact, scientists call it a Super Moon.  (Creative bunch, aren’t they?)  The moon will look bigger than it has since March 1983. 
Full Moons look different in size due to the closeness of the Moon’s orbit to Earth.  Moons do not orbit the Earth in a circular orbit but rather in an elliptical orbit.  (The video here from NASA shows the elliptical orbit.)  On Saturday, the moon will be at the closest point to Earth in 18 years.  The Moon will look 14% larger and 30% brighter.  Time to take out your cameras and telescopes!
Some reporting on the internet has incorrectly hypothesized that the upcoming Super Moon influenced the tsunami in Japan last week.  This is not true.  The Moon does not have enough gravitational pull at any point in its elliptical orbit to influence tides as significantly as we saw in the horrific tsunami last week.

Friday, March 11, 2011

What Caused the Earthquake in Japan?

The entire surface of the Earth is covered by large plates.  These plates are constantly moving very slowly -- an average of two inches per year.  The plates are rubbing together, sinking beneath each other or moving away from each other.  Over time, these movements can cause earthquakes. 

The islands of Japan are located where three plates meet.  Throughout history, Japan has been subject to many terrible earthquakes. 

This short video has a great explanation for how earthquakes happen. 

The USGS has a a website for kids about earthquakes with more videos and educational games. 

Thursday, March 10, 2011

I'm Atoms (Scientific Cover of Jason Mraz's I'm Yours)

Here in Chicago it has been gray for the last three weeks – no sun, just melting snow and rain.  This song made our day.  It has sunshine, great music and atoms!  The lyrics include fabulous lines such as:
“Atoms bond together to form molecules
Most of what’s surrounding me and you…”
This science verse has been set to the music of Jason Mraz’s “I’m Yours”.  This is a must watch!

Saturday, March 5, 2011

How Many Planets Could Support Life in the Milky Way?

Astronomers have recently estimated that there are 50 billion planets and 300 billion stars in our galaxy, the Milky Way.  With the Kepler Mission, scientists have been able to identify exoplanets in the Milky Way and so far have identified 1,235 planets.  Based on this information, Kepler Science Chief William Borucki has said that they have extrapolated from that data that there are 50 billion planets.  Scientist believe that of these 50 billion planets, 500 million could be located in the “habitable zone” of their stars, meaning that they could support life. 
How much is 500 million?  If you took 500 million 3rd graders and placed them touching finger-tip to finger-tip, those kids would make 50 and half circles around the Earth1.  500 million is an awful lot of planets that could potentially support life! 

1)    Assumes each 3rd grader has an average arm span of 52 inches.  Five hundred million kids touching finger-tip to finger-tip would reach 26,000,000,000 inches.  The Earth has a diameter of 7,926.41 miles or 504,357,468 inches.  26,000,000,000 inches divided by 504,357,468 inches is 51.55 times.

Friday, March 4, 2011

Look, it’s the Empire’s Death Star!

Click here to see a photograph of the Empire’s Death Star.  No… wait…  it’s actually Mimas, a moon of Saturn.  Mimas has a large crater named Herschel which makes it look like the Death Star in the Empire Strikes Back.
Mimas was discovered in 1789 by William Herschel.  It is the moon closest to Saturn and the eighth moon orbiting Saturn.  It is quite small at only 250 miles in diameter (approximately the distance from New York City to the suburbs of Washington DC).  The surface of Mimas is dominated by the crater Herschel which was probably created by a large asteroid hitting the moon.  The entire surface of Mimas appears to be covered by smaller craters. 
William Herschel’s son suggested that the moon keep in the tradition of naming celestial objects after Greek Mythological figures.  Herschel named this moon Mimas after the son of Gaia.  Mimas and his brothers were Gigantes, serpent-footed giants.  Ares, the Greek God of War, killed Mimas killed in battle. 
William Herschel built his own telescopes, the most powerful at that time.  In 1781, he had another very important find, Uranus, the first planet identified with a telescope and the first discovered since ancient times. 

Thursday, March 3, 2011

What are UW Badger Scientists Doing at the South Pole?

Hunting neutrinos, of course.  University of Wisconsin professor Francis Halzen developed the idea of the project now called IceCube.  Halzen is a professor of physics and wanted to study neutrinos which are subatomic particles (meaning smaller than atoms).  Neutrinos are emitted by cosmic events such as supernovas and black holes.  These neutrinos are very difficult to find and Professor Halzen theorized that he could locate them more easily in ice. 
IceCube is an observatory that instead of looking at stars looks into ice.  Engineers drilled through the ice with hot water up to one and a half miles deep.  They dug a total of 86 holes.  (See here for a great picture.) Along the way, they placed sensors to detect the neutrinos.  When a neutrino collides with an atom of ice, the collision creates a particle called a muon.  The muon emits blue light and the sensors can pick this up. Voila, Professor Halzen finds his neutrinos.

Wednesday, March 2, 2011

Who’s at the South Pole?

Not Santa Claus – he lives at the North Pole.  There are many penguins, but there are people too.  Approximately 3,000 Americans per year are at the South Pole through USAP (the United States Antarctic Program).  The USAP has had people researching and working at the South Pole since 1956 and currently operates three research stations.  At the Amundsen-Scott South Pole Station, which is at the actual geographic South Pole, the temperature averages -60 degrees Fahrenheit all year.  For six months of the year, the South Pole has sunlight 24 hours per day.  The US is not the only country with people at there.  Forty-eight countries participate in the Antarctic Treaty sending people to research at the South Pole.   Click here to see photographs about the research happening at the South Pole. 
Facts about Antarctica from
·         Antarctica is bigger than US and Mexico combined
·         Antarctica is covered with ice and holds 90% of the world’s ice.  The ice averages over 7,000 feet thick and in some places is as much as 14,000 feet thick.
·         If the ice sheet in Antarctica were to melt, the worldwide sea levels would raise 200 feet.  California, Florida, New York and other coastal states would all be under water!
·         The ice sheet on Antarctica is constantly shifting and moves about 30 feet a year.  Parts of the ice sheet break off and fall into the ocean forming icebergs.  The largest iceberg is the size of Delaware.
This link is the online news center called the Arctic Sun, the source for what is happening at the South Pole. 

Tuesday, March 1, 2011

Not All Starfish Have 5 Arms

The Sun Starfish (Pycnopodia Helianthoides) can have up to 24 arms and be 30 inches in diameter – they’re huge!  In fact, they are the largest starfish in the oceans.  They are quite pretty and come in shades of pink, purple, red, yellow and brown.  However, looks can be deceiving.  The Sun Starfish is a fierce predator.  It loves to eat sea urchin and it will also eat clams, sea cucumbers and its distant relatives – other starfish!  It is very fast and can move three feet per minute.  Like other starfish, they can regrow their arms if lost.  For example, if a Sun Starfish gets caught by a king crab, it can shed its arms to escape the crab’s grasp.  The Sun Starfish’s arms will grow back in a few weeks.