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Galaxy Secrets

4/30/2013

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This image is from the Hubble Space Telescope's "Ultra-Deep Field" survey.  Hubble imaged an area of the sky smaller than a pea's width held at arm's length - over a period of several months in 2003-2004.  The image shows about 10,000 galaxies with the most distant (circled in green & red) about 13 billion light-years away.  That's looking back 13 billion years in time when the Universe was only 800 million years old - and much smaller!  The foreground galaxies act as a "gravitational lens" much like a magnifying glass that enlarges images.  Einstein predicted gravitational lensing as part of his General Theory of Relativity -  which explains how objects bend "space-time" and light. 
Scientists study the most distant galaxies to learn more about the early Universe and galaxy formation.  There are an estimated 125 billion galaxies in the observable Universe - each with millions to trillions of stars.  "The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth" - Carl Sagan "Cosmos" Episode 8.    

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East Coast Meteor

3/27/2013

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The night of March 22nd I was sitting near my living room window with the blinds closed.  A double-flash of intense light that lasted for about 8-15 seconds ocurred that easily shone through the blinds.  Living at the end of a cul-de-sac (and with cloudy skies that night) I assumed it was a large truck with headlights aimed at my house -  turning around.  I had no idea that the light was from the largest meteor that the east coast had seen since 1982.  From Virginia up to Maine people reported the event.  Many local cameras were also able to capture the meteor as it entered the atmosphere.
The east coast meteor of 2013 was still much smaller than the Russian meteor/meteorite that hit on February 15th of this year. 
I was able to witness the Nov. 8th 1982 east coast meteor event.  As a teenager I was walking through a parking lot at Wheaton Plaza with friends that night when we noticed a "fireball" streaking green/red/blue colors across the sky.  The resultant meteorite landed in Connecticut - hitting a house and causing minor damage.  No word (yet) where or if a meteorite will be found from this 1 meter (3ft.) wide object from space.   

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Comet Pan-STARRS

3/10/2013

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Hopefully the weather will "pan" out for this event over the next two weeks. March 12th looks like a good bet to see this "naked-eye" (no telescope needed but binoculars may help) comet with the new cresent Moon about 1/2 hour to 40 minutes after sunset.  Comets are usually named after their discoverer(s) such as "Hale-Bopp" and "Hyakutake" - the last visible naked-eye comets to visit in 1996-97.  This comet was named after a deep-sky survey project called "Pan-STARRS" an acronymn for the "Panoramic Survey Telescope And Rapid Response System" which discovered the comet last year.  Pan-STARRS is a long-period comet fresh in origin from the Oort Cloud - a huge collection of trillions of icy objects located way outside the orbit of Pluto.  Although not as bright in appearance as Hale-Bopp or Hyakutake - due to its distance from Earth - Comet Pan-STARRS will be a nice forerunner for the much-anticipated Comet ISON later on this year.       

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Light & Binary Stars

2/28/2013

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Light is all around us - lets us see things but is still somewhat of a mystery.  Is light a wave or a particle?  Both as it turns out.  Light behaves as a wave but has particle-like features as well (as in "pressure").  Wavelength determines the type of light such as - radio waves (longest) to gamma rays (shortest).  What we see as visible light is just a very small part of a set of millions of frequencies called "color."  Visible light can be broken down and studied.  That's called spectroscopy - or the way light is filtered through a prism or a plastic "diffraction grading" and analyzed.  That's how astronomers can figure out what stars; planetary atmospheres; comets and other celestial objects are made of. 
Binary star systems are two stars that orbit each other.  Most stars in the Universe are part of a "multiple star system" - meaning two or more.  Astronomers know this by breaking down the light sources (spectroscopy)  from what looks like a single star - even in a powerful telescope.  
Planets around multiple star systems (click for the youtube video) are now thought to be more prevalent than single star systems like our Sun (or "Sol").  So a "Star Wars" Universe and the fictional planet "Tatooine" with two suns setting is now way more likely.  Wait for NASA's Kepler Spacecraft to see how many Earth-like planets are out there.      

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Comet ISON

1/9/2013

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Skywatchers are already marking their calendars for the arrival of Comet ISON later this year.  The excitement is real mostlly because we haven't seen such a (potentially) bright comet in the northern hemisphere since Hale-Bopp & Hyakutake back in 1995-96.  Comets are usually named after their discoverers - such as Comet Halley after Sir Edmund Halley in the early 1700's.  ISON was discovered by two members of the International Scientific Optical Network (ISON), a network of observers who track 
man-made space debris.  Vitali Nevski and Artyom Novichonok of Russia made the discovery last September.  (I'm guessing that ISON is easier to remember than "Comet Nevski-Novichonok.")  Either way the comet may rival the Great Comet of 1680 in which Sir Issac Newton himself witnessed and was reportedly seen in daylight!  Comet ISON (currently near Jupiter's orbit) has already brightened as it heads towards the Sun.  This is unusual in that most long-period comets tend to brighten around the orbit of Mars as they head towards the Sun from deep space.   Will this comet pose a threat to Earth (ala the movie "Armageddon")?  No.  The closest approach to Earth will be around 37 million miles - so no worries - just mark your calendars.

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Saturn's Rings

12/19/2012

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Since we are on the subject of the gas giant planets - with Jupiter #1 as far as size & mass - Saturn comes in as #2 but has its own uniqueness.  The extensive ring system for one.  Although Jupiter and the other gas giants all have a ring system - Saturn's rings stand out even when viewed through a small telescope.  Galileo is given credit to discovering the rings although he couldn't figure out what they were at the time (1610).  He famously wrote "Saturn has ears."  It wasn't until later when telescopes were built with better magnification that the ring system labeled A, B & C were discovered.  Today we now know that Saturn's rings are made up of thousands of "ringlets" that are held in place by "shepherd moons" around Saturn.  Since it takes about 29 earth-years for Saturn to orbit the Sun once - we see the rings at different angles.  Sometimes the rings seem to "dissapear" when viewed edge-on (last happenned in 2008).  The rings appear extremely bright because they are made of ice particles that reflect sunlight.  One moon - Enceladus - actually spews out ice particles through cryo-volcanism that may contribute to part of the ring system.  The Cassini spacecraft is currently orbiting Saturn and will continue until 2017.  So stay tuned for even more exciting discoveries with a possible new spacecraft launch to Saturn in 2020!

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Jupiter "Rex"

12/9/2012

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With all the attention seemingly focused on Mars lately, another planet where a spacecraft will further explore will be Jupiter - "King" of all the planets.  The current mission is named "Juno" after Jupiter's wife in Greek & Roman mythology.  Juno the goddess was able to "peer through" her husband's "clouds of deception" to reveal his true nature.  Juno the spacecraft will be able to study Jupiter's gravitational & magnetic fields to figure out what the planet is made of & how it formed (watch NASA video).  The spacecraft was launched in August, 2011 but will begin to orbit Jupiter in October, 2016 - after a gravity-assist fly-by of Earth in 2013.  Juno is part of NASA's New Horizons mission which also includes a fly-by of Pluto in 2015. 
 Jupiter currently can be seen in the night sky as one of the brightest "stars."  The planet is now in planetary "opposition" with Earth which happens about once an Earth-year.  Features such as the Great Red Spot can be seen through a small telescope - with patience.  Soon Jupiter will go into "retrograde motion" as appears from Earth - starting in February, 2014. 

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 TONIGHT: Meteor Trek

12/7/2012

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The Geminids are almost here.  Actually they are here now.  But the New Moon on the weekend of Dec. 13/14 will ensure dark skys (away from the cities) and excellent conditions for viewing 80 - 120 meteors per hour at its peak.  You can look towards the left of the constellation Orion - which is pretty easy to find - after midnight for best viewing.  No telescopes needed.  Binoculars work to observe smoke trails.  The Geminids are named after the constellation Gemini - where most of the meteors seem to originate.  This meteor shower is known for its bright streaks of light and are one of the two brightest of the year (the other are the Perseids in August).  The shower consists mostly of dust particles from the asteroid "3200 Phaethon."  The Geminids are also only one of two showers that do not originate from a comet.  For tips on meteor viewing click here (2009 video but still good advice!)  Let's hope the skies are clear where you are for this one....  and the skies are clear :)

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Mars Organics Part II

12/4/2012

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Not exactly the "holiday" present we astronomy/science geeks were waiting for.  NASA's announcement of "possible" martian organics discovered by the Curiosity rover left room for apparent doubt. 
But that's what the Scientific Method is all about.  Leave enough room - in terms of saying maybe - just in case you need to CYA later if the current new evidence proves even slightly (like .02%) suspect later down the line. 
Kinda like making a 50/50 bet so you never seem to collect the $200 & Pass Go.
Or risk becoming a Meteorologist (just kidding!)
Patience....patience.  The scientific method may seem boring and/or slow but it DOES work........eventually. 
Take a look at the overall data of past & current Mars surface missions.  All have chemically analyzed soils/rocks in about the same way.  Viking I & II were specifically sent to look for microbial life in the martian soil - and had very interesting results in 1976.  Ultimately most scientists agreed that life "most likely" - again a hedge 50/50 bet - did not exist on Mars based on the Viking experiments back then.   
NASA Curiosity project scientists want to be sure about their results as scientifically as possible - and also to CYA just in case.  Remember the Mars Allan Hills 84001 meteorite/fossil debate in 1999?  
One last note:  spending 2.5 Billion on a "super rover" to Mars - you would think that any and all possible "contaminants" like Earth-organics would be a non-argument.  Especially how NASA completely sterilizes anything going to the outer reaches of the Solar System like Jupiter, Saturn & Pluto.  Let alone a planet like Mars - the most Earth-like in the Solar System that early-on once had oceans like Earth.   





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Water Ice on Mercury

11/29/2012

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Water ice has been suspected at Mercury's poles (like the Moon) but not like this - NASA has announced.  On a planet that's so close to the Sun daytime temps. are around 800 degrees (night time negative 300 degrees F).  Craters at the poles are so deep that comet impacts apparently left ice over billions of years - that never sees sunlight (like the Moon).  The MESSENGER spacecraft went into orbit around Mercury last year returning some great pictures & troves of new data. 
Very cool - not that people will be visiting anytime soon.  But I'm sure some future entrepreneur may one day find a way to bottle the stuff & sell it as the "hottest bottle of pure Mecurian water" in the Solar System.


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    astrodad

    Astronomy teacher 20+ years; father of three.

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