Comet ISON Post-Mortem

*sigh*

No, it's not the holiday blues...it's the lack of a comet.

Sadly, it looks like Comet ISON did not fare too well in its first ever (and probably last ever!) trip around the Sun.  The comet was brightening dramatically as it approached the Sun, but then even before perihelion (it's point of closest approach to the Sun) the comet suddenly dropped in brightness...not usually a good sign.  It often heralds a breakup of the object.

Thanksgiving Day saw ISON directly behind the Sun from our view at perihelion...and then, it came back!  But sadly it was much, much dimmer than when it rounded the Sun, and then it proceeded to continue to dim rapidly.  Whatever is left of Comet ISON will not be bright enough to put on any kind of display in our skies this December.

A movie of Comet ISON plunging toward the Sun and then emerging, much diminished, on the other side.  Courtesy NASA and the SOHO Spacecraft.

Ah well.  It was exciting to hope for...but it wasn't meant to be.

We've got holiday fun to cheer us up though - Star of Wonder: Mystery of the Christmas Star and Laser Holidays are back in the planetarium for the rest of this year.  And of course, the December Star Party (December 14) will feature not only those two shows, but also a free concert by the United States Salvation Army Brass Band.  And hopefully the skies will be crisp and clear so we can enjoy the natural celestial show as well.

Still, a nice bright naked-eye comet would have been a wonderful early Christmas present.  Maybe if we're lucky, the Geminid meteor shower will consent to give us a few good meteors on December 14th, despite the nearly Full Moon.  Come join us and find out!

More from the world of astronomy in two weeks...until then...
Carpe Noctem!
Kelly

So What's on Your Mind?

I came to the shocking realization the other day that I've been writing this blog for over a year now.  It certainly hasn't seemed that long to me.

One of the things I was hoping would happen as I began this blog hasn't really materialized yet.  I'd really love to be fielding your questions...talking about the topics that interest you, my readers, the most.  Anyone is welcome to leave a comment on any post - even if your question has nothing to do with the post!  I'll be more than happy to answer your question...and I might even make it the topic for the next blog post.  So please - ask away!

In the hopes of inspiring some new questions, let me share with you the answers to the questions I get asked most frequently.

Who invented the telescope? -OR- Galileo invented the telescope, right?

Actually, Galileo Galilei did many amazing things that advanced our understanding of the solar system we live in, but inventing the telescope was not one of them.  He was the first person to use a telescope for astronomical purposes, turning his simple instrument on the Moon, the Sun, Jupiter, Venus and even Saturn.  But credit for inventing the telescope is generally given to Hans Lippershey, a Dutch lensmaker. 

Hans Lippershey.  Courtesy Wikipedia.

What was that bright thing I saw last night/morning in the east/south/west?

About 99% of the time, the answer to this question is one of the 5 naked-eye visible planets: Mercury, Venus, Mars, Jupiter or Saturn.  Most often, it's Jupiter or Venus, as they are the brightest of these five, with Venus being the brightest object in the sky after the Sun and the Moon.  The planets are generally brighter than the stars near them, and they won't twinkle the way the stars do, making them stand out against the background stars.  These days, Mars is extremely low in the southwest in the early evening.  In the early morning skies, you'll find Jupiter high in the south and Venus mid-way up in the east around sunrise. 

On rare occasions, the answer to this question is Sirius, the brightest star in the nighttime sky.  You'll find Sirius in the winter sky, easily located by following Orion's famous belt to the left.  Sirius will twinkle quite a bit, and it is impressively bright.

Sirius by the Hubble Space Telescope.  The small white dot in the lower left of the image is a tiny white dwarf companion to the main star.  Courtesy NASA.

Where can I buy a quality telescope?

Some camera shops still carry high quality telescopes, but my personal favorite place to purchase observing equipment is online from Orion Telescopes.  They carry an excellent "house" brand, plus the usual players like Meade and Celestron.  Their customer service is excellent, and their prices are quite reasonable.  One word of caution - be wary of purchasing anything manufactured by Meade.  This once-excellent company was bought out several years ago and now offers little or no customer service, and has become increasing difficult to deal with.  Stick with Celestron or Orion's own stuff. 

Where to NOT buy a telescope (especially with the holiday season just around the corner) is any big box store of any kind.  Most "Christmastime" telescopes are cheap, fall apart quickly, and use inferior optical elements.  A good rule of thumb - if the telescope costs less than $150, you are probably going to be disappointed.

When is the best time to see shooting stars in the sky?

Shooting stars are actually meteors - chunks of rock from space coming in to the Earth's atmosphere at high speed.  When they make contact with the Earth's air, the friction generated by the rocks passage causes the air it passes through to glow - making the streak of light we call a shooting star.  While random bits of rock can plunge Earthward at any time, Earth does regularly pass through rocky debris left behind by the regular orbiting of comets.  Such times are called meteor showers, and they are the best times to go out and look for shooting stars. 

The best meteor showers of the year and the rough dates they peak on are:

The Quadrantids  January 4
The Perseids       August 12
The Orionids       October 21
The Leonids        November 17
The Geminids      December 14

I say rough dates because the exact peak date and time changes every year.  In general, the best time to be outside to look for meteors is around 2AM as the combination of the forward motion of the Earth in its orbit and the rotation of the Earth carrying us in the same direction make it more likely that meteors will be visible.  Astronomy is not a hobby for those who like to go to bed early. 

My birthday was yesterday.  Why couldn't I find my sign in the night sky?

Your "sign" is the constellation in which the Sun was located on your birthday.  During the course of the year, the Sun appears in the sky against the background of the zodiac stars, which are part of 12 (13 if you count Ophiuchus, which the ancients really didn't) different constellations.  Today's astrological signs are generally determined by the way the sky looked 6000 years ago, when astrology was getting its start.  In 6000 years, the sky has shifted a fair bit, mostly because very few motions of the solar system actually occur in even numbers of hours or days or months or years.  So what the newspaper says is your "sign" is actually probably not where the Sun really was on the day you were born. 

For example, I was born on November 10.  According to classic astrology, my sun sign is Scorpius the Scorpion.  However, on the actually date I was born...the Sun was located in the constellation Libra the Scales.  6000 years makes a measurable difference in such things.

However, none of that has to do with why you can't find your sun sign constellation in the sky on your birthday.  You can't find it at night, because it isn't there!  By definition your sun sign is in the daytime sky on the day you were born - because it's near where the Sun is on that day.  So if you want to see your sun sign in the sky...wait for 6 months after your birthday.

So what astronomical question have you been longing to ask?  I await your comments eagerly.

Until then,
Carpe noctem!
Kelly

2012: A Year of Astronomical Proportions

Happy New Year everyone!  Once again, I shall ride the current bandwagon, and this post will feature a list of things coming in 2012 that, if at all possible, you should not miss.  Mark these five dates on your calendar now!

March 3, 2012: The Opposition of Mars
No, this has nothing to do with us declaring war on the Martians.  A planetary opposition occurs when a planet is seen exactly opposite the Sun from the Earth, meaning that the planet will rise at sunset and set at sunrise, remaining visible in the sky all night long.  This also means the planet is generally closer to the Earth, as it is on the same side of the solar system as we are.  For Mars, this is a wonderful thing.  Mars has a highly elliptical orbit, and that means that opposition brings our little red neighbor (Mars is only half the diameter of Earth) close enough that details can be seen on the surface with a good telescope.  With a really big telescope...well...you can just imagine.

Mars during the 1997 opposition.  Courtesy NASA, HST & STSci.

This year's opposition is a poor one - even at close approach, Mars will not be as close as it has been in years past - and future oppositions will be better than this one too.  But it's worth seeing the planet nonetheless, even if you don't have a telescope.  Mars is usually a dull orange-ish star in our sky, and not very noteworthy.  But during opposition, Mars will rival Sirius, the brightest star in the nighttime sky, in brightness - a stirring sight for sure.  Right now, Mars rises late in the evening and is visible high in the south around sunrise.  As the year progress, watch for it to rise earlier and earlier in the evening, making viewing this beautiful planet a pretty simple feat even for those who don't like staying up late.  Want to see Mars through a telescope?  Come visit us for our monthly Star Party & Laser Light Night on March 10th.  Mars will be a week past opposition, but still looking great!  Don't miss it!

May 20, 2012: An Annular Solar Eclipse
This one is especially for any readers I might have in California, Utah, Nevada, Arizona, New Mexico and Texas.  On May 20th, as the Sun is setting across those states, the Moon will glide in front of the Sun.  But the Moon will be too far away to cover the entire disk of the Sun, resulting in what is called an annular solar eclipse.  Most of the Sun's disk will be covered, with only a ring of solar surface visible around the Moon.

The Sun during the annular solar eclipse of January 15, 2010 by Mikael Svalgaard.  Courtesy Astronomy Picture of the Day.

IMPORTANT NOTE: Do NOT attempt to view the eclipse without proper eye protection!  Doing so can result in serious damage to your eyes, even blindness.  The Sun's surface, even only a small portion of it, is incredibly bright.  Never look at the Sun with unprotected eyes.  GOOD NEWS: You don't need a telescope to view this amazing event!  The best thing to get is a pair of eclipse glasses - they'll likely be available at your .local science center as the eclipses gets closer, or you can order them online.  Or, for a quick, inexpensive solution - buy a piece of Shade #14 Arc Welder's Glass from a local hardware store, and look at the Sun through that.  Make sure you get Shade #14 - no other shade will work.  Once you've protected your eyes - go outside about an hour before sunset (check your local paper for exact times for your area!) and watch the Sun as it goes down.  It will be an amazing view.

June 5, 2012: The Transit of Venus
Okay folks, this is the big one.  If you see no other astronomical event this year - see this one.  Why?  Because, quite literally, you will not have another chance to do so in your lifetime.  There will not be another transit of Venus for 105 years - so this is your one and only chance.

A transit is kind of the opposite of opposition - in this case, a planet is crossing in front of the disk of the Sun as seen from the Earth.  Naturally, we can only see transits of Mercury and Venus - the only two planets which lie closer to the Sun than we are.  You'd think these would happen all the time, but like eclipses, the geometry doesn't always work out.  Most times a planet passes above or below the Sun from our perspective.  But every so often the geometry is perfect, and we get to see a planet silhouetted against the brilliant face of the Sun.

The 2004 Transit of Venus photographed by Stefan Seip.  Courtesy Astronomy Picture of the Day.

The transit of Venus this June will occur close to sunset for us, and you can bet we'll be watching here at the Virginia Living Museum!  Stay tuned for more information on our Transit of Venus event.  While the transit will be visible unmagnified with suitable eye protection (remember the warning above!), it will be better through a telescope.  If you're local to Hampton Roads, plan to come join us!

December 13, 2012: The Geminid Meteor Shower
Meteor showers are always fun, and there are usually a couple good ones each year.  But if you're only going to bundle up and sit outside for several hours once in 2012, wait until the December Geminids.  The Moon will be new, making this a perfect night for stargazing in general.  The shower will peak around 7pm local time, meaning you don't have to go outside in the middle of the night to enjoy a good view.  Simply find a dark location (the fewer lights the better!), set up a comfortable lawn chair (laying back so you can see a lot of the sky without straining your neck is best), pile on some blankets and enjoy the show.  The meteors will seem to come from the constellation Gemini the Twins, so if you can place those stars at your back, so much the better.  You can watch until the wee hours of the morning if you like...2am is often a good time to see meteors as our part of the Earth will be turning into our direction of motion, making for good meteors!

A 2011 Geminid meteor over Iran photographed by Arman Golestaneh.  Courtesy Astronomy Picture of the Day.

December 21, 2012: The End of the World
Okay, this one really isn't an astronomical event.  In fact, it's not really an event at all.  Well, it is the Winter Solstice, but you can't really "watch" that event unless you plan on setting up a camera and waiting a year.

 The Analemma over the Porch of Maidens in Athens, Greece as photographed by Anthony Ayiomamitis.  Courtesy Astronomy Picture of the Day.  The Winter Solstice is the Sun's lowest point in the sky. 

But you're probably aware of the numerous predictions of doom and gloom for our planet surrounding this date.  I always love it when such things come up, because it gives us a great opportunity to educate folks about science and how it works...and how it doesn't.  Want a primer on what all the fuss is about?  Join us for 2012: The End of the World? NOT!, a brand-new planetarium show which will be featured all year at the Abbitt Planetarium.  And stay tuned for more information about our End of the World Party, currently in the planning stages. 

So there it is - what not to miss in 2012.  May it be a year of astronomical proportions for all of us!
Carpe noctem!
Kelly