Archive for the ‘NEO’ Category

Longing for Leonids

Monday, November 9th, 2009
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1999 Leonids - Credit: Shinsuke Abe and Hajime Yano of the Institute for Space and Astronautical Sciences, Japan

(*Note: It has been brought to my attention, by Daniel Fischer, that the predicted outburst rate of 500zhr, noted herein, has been amended to 200zhr)

Surprisingly, I did not experience my first meteor shower until I was 35 years old.  But, that first shower was the Leonids “storm” of 1999, and it was worth a lifetime of meteor showers.

In 1999, I wasn’t yet involved in astronomy, and having never experienced a meteor shower, I really didn’t know what to expect.  But, I’d heard that an outburst had been predicted, and I was intent on finally experiencing a meteor shower.  So, on the night of November 17, I dawdled around the house until about 3am, then I roused my husband and youngest son from bed and we headed for the safest, darkest spot we could find.

As it happened, we needn’t drive far.  Even as we pulled out of our neighborhood, fast bright meteors were streaking across the sky.  Within minutes, the streaks were so many that we simply pulled over to the side of the road and set-up camp right there, in a small field.

I’ll never forget that night.  It was bitterly cold, but we were properly dressed and had plenty of blankets.  Though no stars were visible through the clouds, hundreds of colorful meteors filled the sky.  Not only could we see them, we heard them fizzing and popping.  It was as though you could reach out and grab them; some even seemed as though they’d strike us.  At one point, my two-year-old son even began to cry, thinking that we were under fire from some angry farmer.  And all up and down that road, late-night drivers were pulling over as the brilliant sky came raining down.

Now it is ten years later, and it looks like we may experience that once-in-a-lifetime event, yet again.  Astronomers from CalTech and NASA are predicting an outburst of 500 streaks per hour, with Asia being favored for the greatest activity.  While this is less than one-quarter the activity of the 1999 event, and half that required for a real “storm”, 500 meteors per hour is intense!

Scientists are basing this year’s prediction on Earth’s movement through the debris field of the periodic comet, 55P/Tempel-Tuttle.  We orbit through this material every year, but this year Earth will pass within 42,000 miles of the center of a particularly rich stream, left by the comet’s pass in 1466, as well as through two additional streams, dating back to 1533 and 1567.  As we move through that expelled material, tiny particles will impact our atmosphere at speeds of 160,000 mph, creating the fiery display of a meteor shower.  It is a fascinating scenario to envision, and even more exciting to witness, as one sits under a dark moon-less sky, counting the bright streaks.

The best time to view most meteor showers is in the early hours before sunrise.  With the Leonids, the streaks will appear to originate from the constellation Leo, near a curved group of stars, known as the “sickle” and representing the mane of the Lion that is Leo.  Although Asia will be best-placed for the main outburst, as Earth moves through that denser 1466 stream at 21:40 GMT on November 17, North and South America should experience significantly-heightened activity when we encounter the 1567 stream some 12 hours earlier, on the morning of the 17th.

Of course, peak nights are not the only time one can enjoy the Leonids, and watching is not the only way to experience them.  Nights immediately preceding and following the 17th should also see notable activity, offering extended viewing and listening opportunities.  You’ll also likely find a number of Leonids-related events in your region and online, or you could even consider hosting your own meteor-watching party to introduce friends and neighbors to the wonders of the night sky!

* Wanna know more about meteor showers?  Check out Space.com’s “Meteors and Meteor Showers: The Science“!

* Source Material: NASAMeteor Showers Online, Society for Popular AstronomySpace.com, Quick Phase Pro, Stellarium

Look Up, Log In, or Listen: An Exciting Week of Astronomy!

Monday, October 19th, 2009

If you ever needed an excuse to go out and look up at the night sky, this week is it .  In fact, astronomy is so hot right now, you can even stay inside and enjoy many of this week’s events right from your computer!

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Moon-less Nights … First, the frosting on the cake (I always did like dessert, first) … We had a New Moon last Saturday evening!  That means a lovely crescent Moon at sunset and “moon-less” nights for darker skies!  Perfect timing for a week full of astronomy opportunities!

Moons You’ll Like … Jupiter’s Galilean satellites are putting on a show this week, with three occultations for eastern North America.  No doubt you’ve noticed Jupiter as that brightest “star” on your south horizon after sunset.  Even smaller binoculars will reveal the giant planet’s four largest moons, but you will need a telescope to fully appreciate the occultation events.

Shooting Stars … Those aren’t stars – they’re comet debris!  Heralding in this exciting week, the Orionids Meteor Shower is in full display right now.  Maximum occurs over the next three mornings, with peak expected on Oct. 21st (late Tuesday night / early Wednesday morning.)  Named for its apparent point of origin – the radiant is just east of Orion’s Betelgeuse – this shower is the second of two yearly passes through the debris trail of Comet Halley.  Currently, Orion rises around 11pm local time, so your best observing will be after midnight.  While the Orionids is not an especially prolific shower (20-30 zhr,) it is consistent and the streaks are distinctively quick and bright.  This year should offer an especially nice show with those moon-less nights.

Counting Stars … The Great World Wide Star Count winds down this week.  Counting stars is another activity best done on a moon-less night.  This citizen science event is a fun and easy way to learn more about the night sky, raise awareness about light pollution, and participate in the International Year of Astronomy 2009.

A Sky Full of Stars … On Wednesday evening, Rob and I will host a special edition of A Sky Full of Stars on AFM*Radio.  We’ll feature guests Adrian West, of the Newbury Astronomical Society (@NewburyAS), and young astronomer-extraordinaire Elias Jordan (@ksastro) to talk about some exciting upcoming astronomy events, including this year’s second Twitter MoonWatch and the IYA 2009′s  Galilean Nights.  The live show airs Oct. 21st at 8pm EDT (Oct. 22nd, 00:00 UTC)  – we’ll post the podcast version here and at Astronomy.FM.

Star-Filled Nights … Speaking of Galilean Nights, Astronomy.FM is celebrating with two special events this week.  First, they want to help you capture the stars with free imaging sessions from Global-Rental-A-Scopes.  Then, on Saturday evening, the Marleen Bryan and I will feature all things Galileo, with a special Galilean Nights edition of the DeepSkyDivas.  If you haven’t yet checked out Astronomy.FM, this is a good time to do it.  AFM offers an enthusiastic international community, a members forum, radio events, a daily Amateur Astronomer Picture of the Day (AAPOD), and regularly-updated space and astronomy news.  The DeepSky Divas airs, live, Oct. 24th at 9pm EDT (Oct. 25th, 01:00 UTC).

A Red Planet … While you’re out watching for meteors, see if you can spot the planet Mars, directly beneath Gemini’s Castor and Pollux.  Currently, Mars rises around midnight, about an hour behind Orion.  As you look at Mars, consider this – there are currently five crafts exploring our red neighbor.  Three crafts are orbiting the planet and another two are roaming its surface.

Morning Planets … Venus and Saturn grace the morning sky this week.  You’ll find the two together on your east horizon in the hour before sunrise.  Take advantage of this opportunity to see Venus before it leaves the morning sky next month.

Close Calls … Last but least  – this event is one that you can’t see, but it is something you’ll probably find very interesting.  Seventeen near-Earth-objects (NEO) will be passing our planet this week; thirteen were discovered just this year.  Seven of the seventeen will pass within just 10 lunar distances (LD) – the closest of those passed at a mere 2.5 LD last night!  Most of this week’s NEOs are smaller objects, measuring tens of meters wide.  Only two are considered larger objects, with the largest being 1.7 km – 3.8 km.

So, there you have it – opportunities to Look Up, Log In, and Listen – all with an eye on the stars!

Mercury with Pleiades

Wednesday, April 29th, 2009

Last night’s sunset viewing was gorgeous.  A few thin clouds drifted through and ground-level moisture kept me busy drying dew, but the sky was beautiful and the stars were bright.

Although I had more success through the binoculars than the camera lens, I did manage a couple of okay images of the crescent moon and Pleaides with Mercury, as well as a just-for-fun image of a passing jet. (You can click the first image for full-sized version, and then click next at the top-right corner of the image to scroll through to the other two images. Click the x in the bottom-right corner to close the images.)

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Sharing the Sky

Sunday, April 26th, 2009

I am so pleased.  I found a very nice horizon for tonight’s sunset event, and it is in a safe and comfortable location!  It is near the edge of a pretty little pond full of serenading frogs and surrounded by a small field that includes wild rabbits and killdeers.  There are a couple of streetlights in the near vicinity; fortunately, they are a timer that turns them off and on every so often.  I’ll be visiting this special spot often.

Watching tonight’s conjunction was so enjoyable.  The weather was perfect – just enough of a light breeze to keep the mosquitoes away – and the sky was very clear.  The pink and red hues of the sunset were gorgeous, especially when that thin crescent moon suddenly appeared in the still-blue region just above; and then of course, Mercury and Pleiades added perfect sparkle as the sky grew darker.  Several distant airplanes passed through, adding occasional luminous trails to the view.  I even managed to capture one crossing directly in front of the moon.

As I stood there, watching and waiting, I couldn’t help but think of the friends that I’ve made lately and how many of them were probably standing outside their own homes that very moment,  feeling the same way that I do about the night sky.  I thought about the way that those friendships formed across so many miles through one common passion – astronomy – and how those friendships have been my single most valuable resource in my own pursuit of astronomy.  I could read a thousand books, visit a hundred websites, own all the astronomy tools in the world, but without those friendships – that sharing of experiences, knowledge, and excitement – astronomy just would not be the same for me.  I would be just as curious and have that same feeling of wonder, but the pursuit would be almost mechanical and certainly lonely.  Being alone with the stars is one thing – in fact a marvelous thing – but having no one with whom to share that oneness … well, I think it would take the heart and soul right out of astronomy, for me.

This is a meager offering (I wish I were a better photographer) but these pictures of tonight’s conjunction are for my astronomy friends – for all that you give simply by sharing your passion with others, and for allowing me to share with you. (You can click the images for the full-sized versions, and click the x in the bottom-right corner to close.)

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 Luna with Pleiades

Mercury and Pleiades at Sunset

Saturday, April 25th, 2009

Well, I struck out on this evening’s “thinnest” crescent moon – I never could find a clear enough horizon – but I did capture Mercury and Pleiades at sunset.  Although I’m not entirely pleased with the image, I am happy to have had the opportunity to see this pairing.  Tomorrow evening, the Moon will be a little more illuminated and will set a little later, making a sighting much more likely.  I’m looking forward to seeing it with Mercury and Pleiades!

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Image Specs: Canon XTi/400D, 6secs., 55mm, f/5.6, ISO400

Looking at Luna

Friday, April 24th, 2009

This weekend offers two excellent opportunities to observe a very thin crescent moon at sunset.  It’s also a good time to capture some nice “earthshine” images and spot the planet Mercury.

Saturday evening, the new moon will be mere hours old – the thinnest of slivers – with it’s actual age depending upon your location and what time you are observing.  Sunday evening, the moon will be less than two days old – still a thin sliver – and will appear in close position with Pleiades and Mercury.

On both evenings, you’ll find the moon just above your WNW horizon.  On Saturday, Mercury appears above and slightly left of the Moon.  On Sunday,  Mercury appears closer to Luna, this time beneath it, with Pleiades in the middle to form a beautiful trio of objects both near and distant.

Using your binoculars, you can get a good look at that darker portion of the Moon – that region not illuminated by direct sunlight – known as “earthshine.”  We call this ashen-colored region of the Moon “earthshine” because it is the Earth’s own reflected sunlight that makes it visible.  Surprisingly, it was Leonardo Da Vinci, even before  Copernicus’ sun-centered theory, who first described the source of the moon’s illumination, including the secondary glow of earthshine.

Once you’ve browsed the lunar surface, have a look at Mercury.  You might notice a pinkish hue, and this is due to our own atmosphere, just as sunsets and a rising moon sometimes display a red or orange tint.  Of course, you’ll have to focus on Pleiades, as well.  This beautiful cluster is much more distant, but younger than either Mercury or the Moon.  The Pleiades cluster contains about three-thousand member stars, some one-hundred-million years old, and is positioned more than four-hundred light-years away in the constellation Taurus.  Even at that distance, this cluster is actually one of our galaxy’s closest.

Luna currently appears close to the Sun, following it into the horizon at sunset, so you’ll have to keep two things in mind.  One, use special care when observing anywhere near the sun and never ever look directly at the sun through unfiltered binoculars or telescopes.  Two, start your observations before full darkness sets in, else you may find the moon already too low from your location.

For local lunar calculations, I use an excellent program called Quick Phase Pro.  You can also check out the U.S. Naval Observatory for regional lunar information.  Both programs offer lunar rise/set/transit times, phase information, and lunar illumination.  The Quick Phase program offers a few more details, like phase age and historical data.

If you’ve never taken a picture of the moon or evening sky, this is a good time to give it a try.  Any camera should work fine; and remember, it’s not so much how accomplished an image appears, rather, its that you accomplish the effort of imaging.  For better results, take several pictures, changing your settings if your camera allows.

So, get out there this weekend and have a look at Luna; and if you do capture some images, share them with us.  We’d love to see your work.