Debris from Haley's Comet Triggers Meteor Shower

Comets are truly unique objects in our solar system.  They reside out in the coldest depths of space, barely held by the sun's gravity; yet all it takes is a tiny nudge to send them looping in toward the inner solar system where they become spectacular.

Because comets are composed of rock, and frozen gasses of different kinds.  As they approach the sun, the frozen gasses return to their gaseous state (a process called sublimation) and stream off behind the comet.  In addition, some of those gasses get ionized and form a secondary tail (which isn't always visible to the naked eye). 

Sometimes the comet is flung back out into interplanetary space, to return again at some distant date.  Sometimes it is completely destroyed by the sun's radiation. 

However, comets also leave behind tiny bits of dust and rock that hang out in space, much the way smoke hangs in the air here on Earth.   If this debris trail happens to cross the orbit of the Earth, the stage is set for a meteor shower.  As Earth passes through the debris from the comet, the pieces of dust enter our atmosphere and burn up.  Since the debris field isn't exhausted as Earth passes through, it can cause a recurring meteor shower.  

In the case of Haley's comet, the recurring meteor shower it causes is the Orionid's meteor shower.  The name of any meteor shower comes from the constellation the meteors appear to come from (known as the radiant)  

The best time to view the Orionids is well after midnight, when Orion is highest in the sky.  Forecasters are predicting up to 20 meteors per hour for this year's shower.  The best way to observe any meteor shower is to bundle up and lay down in a lawn chair.  

Image of meteors from Orionid's Shower
Created with Stellarium

Lunar Observing Tips

Last Saturday was International Observe the Moon Night.  An opportunity for observers around the world to observe the moon, learn about its features and share some experiences.  Usually local astronomy clubs set up a variety of telescopes to give an "up close and personal" view of Earth's only natural satellite. 

International Observe the Moon Night is usually held in October, on a weekend close to the first quarter phase.  First Quarter is actually the best time to observe the moon for several reasons.

First, it rises about noon and so is easily visible in the evening for several hours after sunset. It is also highest above the horizon after sunset which means there is less atmosphere to gaze through, and therefore less distortion. Third quarter moon is similar in how it reflects light, but it doesn't rise until well after midnight.

Second, when the moon is at First Quarter, the light from the sun is not striking the surface directly but rather at a low angle.  This causes the the mountains and craters to stand out in sharp relief, showing off their height and depth.  At full moon phase the lunar features look flat, sort of like looking at a bright light reflected off a dinner plate.  

Using a telescope is great for observing the lunar features, but it's best not to use too much in the way of magnification.  While the moon will look like it's "right there" it will also zoom out of the field of view pretty quickly, requiring more adjustments.  Lower magnification lets you see the entire disk of the moon and therefore enjoy more of the whole experience.

First quarter moon is best for observing its features.
Created with Stellarium

Rest in Peace Scott Carpenter

Sorry I've been away folks, the job has been crazy and I have a LOT of downed tree branches from the big snow storm last weekend.  

When I was in High School, our marching band played the theme from a movie called The Right Stuff.  Naturally it led me to want to see the movie and from that moment I was hooked.  I absolutely loved the story of the Mercury Astronauts.  They were an amazing group of men and truly worth admiration.

Today there is only of the Mercury 7 left, former Senator John Glenn.  It saddens me because, like the heroic veterans who save the world from Nazi Germany in World War II, these great men are leaving us one by one.  

The following story by Nancy Atkinson at Universe Today is a fitting tribute to the second man to orbit the Earth.

Mercury Astronaut Scott Carpenter Dies

Astronauts Carpenter & Glenn pose in front of a Mercury Spacecraft.

U.S. Government Shutdown Closes Down More than National Parks

The shutdown of the U.S. Government has closed more than just National Parks and the museums of the Smithsonian.  The shutdown has also closed down great scientific websites such as NASA, NASA's Earth Observatory, the Astronomy Picture of the Day, and the National Science Foundation.

But there are other downsides to the shutdown.  For example, the Hubble Space Telescope is owned by NASA but operated in conjunction with an institute.  This means it can continue to operate on existing funds provided the shutdown doesn't go on to long.  However, scientists around the world compete for the chance to decide where the telescope points.  As long as the government is shut down, the science panels that decide who wins those observing times are shut down as well.  Literally hundreds of hours of observation are simply gone.  

The following article from CNN explains how the shutdown will affect other science missions, and makes the US Government shutdown more harmful than we previously thought.

Shutdown a huge waste and cost to science

Algol, "The Demon Star" Reappears in the Night Sky

October is traditionally the month when thoughts turn to monsters, ghosts and spooky stories.  The night sky also has its fair share of monsters and frightening creatures.  One of the most famous is not a constellation itself, but is part of the constellation Perseus the Hero.

Perseus the hero is famous for slaying Medusa the Gorgon, who was so hideous that a single glance from her would turn any living creature to stone.  Perseus used the reflective surface of the inside of his shield to safely hunt the monster and cut off her head with a single stroke of his sword.  He then used Medusa's head to rescue the princess Andromeda from Cetus the Sea Monster (who is also in the fall sky).

The constellation Perseus depicts the hero holding Medusa's head.  The star Algol (ß Perseae) represents the eye of Medusa.  Algol has long been known as the Demon Star because it changes its brightness over a period of nights; like the eye of Medusa slowly opening and closing.  

We now Know that Algol is an eclipsing binary star.  An eclipsing binary is a pair of stars that orbit around each other in such a way that they alternate passing in front of each other, thus eclipsing.  In the case of Algol one star is a bright white star and the other is a dim red star.  When the red star passes in front of the white one the light from the white star is cut off or eclipsed. This means the brightness alternately drops and then brightens.  

Binary stars weren't observed until the advent of the telescope.  Yet a special binary star has been known to ancient times,  and it is perhaps fitting that one of the spookiest begins to appear in our sky as October rolls around.  

Eclipsing Binary star Algol in Perseus. Created with Stellarium.

SOHO Catches a Magnetic Filament Eruption.

The current Solar Max has been less than spectacular.  It has shown fewer sunspots, fewer CME's (Coronal Mass Ejections) and fewer erupting magnetic filaments.  

However thanks to the SOHO (Solar Heliospheric Obervatory) and the Solar Dynamics Observatory, there are eyes on the sun for even the smallest events.  

Two movies show a good sized magnetic filament erupting on the sun's surface.  The event also shot a CME into space that may deliver a glancing blow to Earth's magnetic field on October 2-3.  

Also check out the article on  SpaceWeather.com

Earthquake Raises New Island Off Coast of Pakistan

If anyone doubts the power of the planet we live on, this story from NASA's Earth Observatory should put those doubts to rest.  

Earthquakes occur along fault lines, fractures in the Earth's crust.  The land masses that join along a fault are under tremendous pressure, but friction keeps them from moving.  However, eventually the pressure overcomes the friction and the fault slips causing an earthquake.

In the case of the earthquake off Pakistan,  the Earthquake caused enough mud from the sea floor got pushed up to form a small island. 

The article is a great review of earthquakes, tectonic forces and island formation.  It is also a great reminder of how small and fragile we humans are compared to the planet we live on.

Earthquake Creates New Island off Pakistan

New Island forms off Pakistan. NASA's Earth Observatory.