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!