Archive for the ‘asteroids’ Category

Visualizing Our Busy Neighborhood

Sunday, August 29th, 2010

It’s one thing to read about the discovery history of asteroids; it is another to visualize it.  Astronomer Scott Manley has created a fantastic animation illustrating the known positions of all asteroids discovered in the past three decades.  Each new discovery appears as a white object and then evolves to either yellow or red for near-Earth-asteroids, or green for all others.

While the animation is not to scale – Space is not so crowded as it appears in the video – it does offer a great comprehension of how frequently we are discovering new objects, especially in the last decade, and of just how busy our inner solar system really is.  Hundreds of thousands of asteroids have already been discovered, more than seven-thousand of which pass near or across our own planet’s orbit.  Scientists estimate that there are probably millions of undiscovered asteroids residing in the Main Belt, with about 750,000 measuring greater than one kilometer, and hundreds of thousands of which are likely near-Earth asteroids.

The most interesting thing about Manley’s animation is the discovery pattern.  As noted in Manley’s You Tube description, most discoveries are made in the region directly opposite the Sun and many are obviously related to specific missions and surveys, such as the automated sky surveys, the more recent WISE mission, and even past searches for Jovian satellites.

Kudos to Scott Manley for this creative way of bringing the more intricate details of solar system discovery down to Earth!

*Click the full-screen option and turn up your sound.

1 Dusty Determination + 1 Serendipitous Solution = 2 Mysteries Solved!

Saturday, April 17th, 2010

An exhaustive study, led by the SETI Institute’s Peter Jenniskens and planetary scientist David Nesvorny of Colorado’s Southwest Research Institute, has solved two long-standing mysteries.   Interestingly, it was the study of one well-known phenomenon that serendipitously solved a second, lesser-known mystery.

The primary focus of the NASA-funded study was to determine the true origins of zodiacal light.  Originally attributed to the scattering of sunlight by solar system dust – an explanation recently refined to specify asteroid dust – the zodiacal light extends as a glowing cone up from the sunset or sunrise horizon to the ecliptic.  Although this ethereal light is so tenuous as to be rendered invisible by moonlight and light pollution, it is readily apparent in darker skies and even bright enough to be followed across the ecliptic in the very darkest conditions.

In their paper, Cometary Origin of the Zodiacal Cloud and Carbonaceous MicroMeteorites – Implications for Hot Debris Disks, Jenneskins and Nesvorny confirm the zodiacal cloud mass as originating primarily, not from asteroids, but from the past violent and repeated disruptions of Jupiter Family comets.  Moreover, these disruptions likely resulted in twenty-trillion-tons of dust, with hundreds-of-thousands of tons impacting our planet every day!

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Of Fusion Crusts and Strewn Fields: Science Channel’s “Meteorite Men” Make an Impact

Tuesday, March 2nd, 2010

PHOTO CREDIT: Photograph by Caroline Palmer © Aerolite Meteorites www.aerolite.org

Join us Sunday, March 7 at 9pm EST (March 8 at 0200 UTC), for a special AFM*Radio presentation featuring Geoffrey Notkin of the Science Channel’s Meteorite Men!

In a pre-recorded interview, we speak with Geoff about all things Meteorite Men, including how the show came to be, some surprising results of the show, and his remarkable fourteen-year friendship with Meteorite Men co-host, Steve Arnold.  Geoff also discusses some of world’s more fascinating impact sites, the intricacies of meteorite hunting,  and his own passions for science, meteorites, and music.

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Webcast Archive: “MoonWalking with Rob Self-Pierson”

Friday, December 18th, 2009

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12/23/2009 Update: Video archive of this webcast can be found here.

Throughout billions of years, the Moon has held an intrinsic practical and emotional bond with our planet.  Sadly, we are losing the human connection as we keep our eyes fixed on the material and social noise of today’s world.

Every once in a while, something special comes along to remind us to pause and look up at Luna, to consider that constant, though oft-forgot, guidepost for all living things on Earth.

We are proud to announce our next AFM*Radio special event, an audio/visual presentation, Moon-Walking with Rob Self-PiersonJoin us next Tuesday night, Dec. 23 0100 UTC (Dec. 22 8pm ET), when Rob Self-Pierson stops by to discuss his “MoonWalking” experiences and his upcoming Blue Moon Walk.  We’ll feature images, video, an interactive chatroom, and details about how you can participate in commemorating the last Blue Moon of this decade!

Dream a Little Dream – Under the Blue Moon

Wednesday, December 16th, 2009

Blue Moon / You saw me standing alone / Without a dream in my heart …

Actually, I do have a dream …  Blue Moon / I’ll be standing with you / Without a cloud in the sky

For many people, December 31st will mark the last day of another year, just as it ends every year of the Julian Calendar.  But, for sky enthusiasts, this December 31st has poignant meaning, marking the end of a very exciting year of astronomy outreach – the International Year of Astronomy 2009. So, it seems most appropriate that this wonderful year of sharing the night sky should end with a Blue Moon!

But, what is a Blue Moon?  We often use the term to reference a rare event – “once in a blue moon” – but is the Moon ever really blue?

Actually, on rare occasions, the Moon does “appear” blue due to specific atmospheric conditions, thus that reference for rare events.  But, more often, the term “Blue Moon” defines an “extra” Full Moon within a given calendar, an event that can be credited to the Julian/Christian calendar, farming cycles, and the tradition of naming Full Moons, rather than any cosmic phenomenon.

Of course, there never really is any “extra” moon.  The Moon orbits our planet, phasing through New to Full with such consistency that it occasionally clashes with our less-precise, seasonal timekeeping.  This leaves us with an “extra” moon about every 2.7 years – and we account for it with the name “Blue Moon”.  For yearly timekeeping, this Blue Moon occurs as the thirteenth of a twelve-moon calendar; for seasonal timekeeping, it is the fourth of a three-moon season; and more recently, due to an interpretation error in the mid-twentieth century, a Blue Moon is the second Full Moon in a one-month period.

This year’s Blue Moon just happens to fall on December 31 – the last day of the month, the last day of this year, and the final day of a decade.  On that day, I’ll be there to watch it, rising on the east horizon at sunset – big, bright, and full of promise – as I reflect on the successes of a year of star-filled outreach.  And then I’ll return at sunrise, to watch as that same Moon – the last Moon of this century’s first decade – sinks into the west horizon, bringing forth a New Year under the Milky Way and another decade of new discoveries.

*For a real treat, pop over to Rob Self-Pierson’s Moonwalking site and check out his beautiful #BlueMoonWalk video!

AFM*Radio Event: #SaveNASA (But, Why?)

Wednesday, November 25th, 2009

savenasaIf you are a fan of NASA’s Space program, you are probably also well aware of NASA’s budget constraints.  Good science does not come cheap and this is especially true of Space-related studies, whether they be Earth-based or beyond.

Tonight, A Sky Full of Stars, in collaboration with Astronomy.FM*Radio, welcomes #SaveNASA founder, Neal Wiser, for a serious discussion about the state of Space-funding – why should we even be concerned about Space-science, and what can we do to effect NASA’s greater future?

NASA’s endeavors affect each and every one of us, so we want you to be part of tonight’s discussion.  We’ll open a virtual conference room, where listeners can share their thoughts and ask questions during the show; and we’ll also take questions and comments via Twitter at @aSkyFullOfStars and @Astronomy.FM.

Tonight’s presentation begins at 9 pm ET (0200 UTC).  You can access the conference room, which we’ll open about ten minutes before showtime, via the big blue widget on the Astronomy.FM home page.  This room does include audio, so if you’re listening to AFM*Radio before the show, be sure to turn off your media player to avoid a double-audio echo.

If you’d like to do a little research before the show, you’ll find NASA’s budget information, here, and President Obama’s recent Science, Technology, Engineering, and Mathematics Education speech, here.  We are excited about tonight’s presentation and look forward to everyone’s participation!