Podcast: Lucas Macri on the Extragalactic Distance Scale

We have a new podcast on the feed and once again it is the extended version of our most recent contribution to The 365 Days of Astronomy Podcast. Michael Koppelman interviews Dr. Luca Macri of Texas A&M University about his work on the extragalactic distance scale.

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This podcast is brought to you by Swinburne Astronomy Online, offering fully online degree programs in astronomy.

Dazzling Display of Promethean Force on Saturn’s F Ring

more cool ring structures.
–Ben
————————————-
July 20, 2010

Dear Friends and Colleagues,

Today, the Cassini Imaging Team is proud to release some outstanding new image mosaics and computer simulations of everyone’s favorite ring, Saturn’s F ring: the narrow, dynamic, and extraordinarily complex set of strands of ring material caught between the orbits of its shepherd moons, Prometheus and Pandora, a few thousand kilometers beyond the outer edge of Saturn’s main rings.

These new results, published last week in the journal Astrophysical Journal Letters, confirm what some of us veteran imaging scientists from the days of the Voyager mission long suspected: The F ring is the site of continual moonlet formation and, in most cases, eventual disruption. But what we didn’t know then was the exact mechanism by which this could happen.

Now we do, and the culprit is Prometheus and the particular sequence of steps that transpire in its repetitive disturbance of the F ring that creates clumps of ring debris.

And like so many of our most interesting results on Saturn’s rings, the tell-tale clues came in the form of shadows cast by these small, newly formed objects onto the faint, diffuse component of the F ring.

Go to …

http://www.ciclops.org/view/6367/Fan_in_the_F_Ring

… and see for yourself what Prometheus inflicts on the F ring. And be amazed at the complexity that is made possible by the simple force of gravity.

Enjoy!

Carolyn Porco
Cassini Imaging Team Leader
Director, CICLOPS
Space Science Institute
Boulder, CO

http://ciclops.org

http://twitter.com/carolynporco

http://www.facebook.com/pages/Carolyn-Porco/116163229386

Astrofest 2010

step away from the computer and go ‘LOOK’ at something.
–Ben

================================
from : Jim Cuca wglogowski@gmail.com

Dear astronomy enthusiast:

The Chicago Astronomical Society invites you to attend our annual star party, Astrofest, which will be held September 10-11, 2010 at Vana’s near Kankakee, Illinois. Registration forms and related information are available at

http://www.chicagoastro.org/index_files/Page345.htm

The theme for this year’s event is “The Link Between Astronomy and Particle Physics.” In addition to our usual line-up of astronomers, Astrofest 2010 will include presentations by scientists involved in research into such contemporary topics as dark matter and dark energy. Our star party will be held on Vana’s 20+ acre field, with plenty of room for camping and telescopes; each attendee will be invited to use our 14-inch observatory telescope. Other activities include: astrophotography contest; telescope contest; door prize raffle.

We hope to see you at Astrofest 2010.

If there are any questions, please contact

Jim Cuca at jamescuca@comcast.net.

OSTP to Co-Host “Astronomy Night on the National Mall”

another astro event in DC.

WOW!

–Ben

OSTP to Co-Host “Astronomy Night on the National Mall”

OSTP, in conjunction with Hofstra University, will co-sponsor a free, open to the public star party July 15 on the National Mall in Washington, DC.

If you are near the DC area in come enjoy close-up views of the crescent Moon, Venus, Mars, Saturn, star clusters, and nebulae. You can even gaze at our own Sun early in the evening with the help of specially filtered telescopes. “Astronomy Night on the National Mall” will go from 6 p.m. to 11 p.m. on Thursday, July 15 (with a July 16 rain date). Telescopes, posters, and video equipment will be set up just northeast of the Washington Monument, between 14th and 15th Streets NW, and Madison Drive and Constitution Ave. View a map of where Astronomy Night on the Mall will be held…

http://www.whitehouse.gov/blog/2010/07/03/ostp-co-host-astronomy-night-national-mall

Latest from Cassini! Large Propeller Features Found in Saturn’s Rings

Cool.

“…the giant propeller “Earhart” named after another aviator, Amelia Earhart….”

–Ben
——————–

July 8, 2010

Dear Friends and Colleagues,

Today, a paper published in the Astrophysical Journal Letters by members of the Cassini Imaging Team reports the discovery of dozens of kilometer-sized moonlets in Saturn’s outer A ring, eleven of which have been carefully tracked over the last few years.

Embedded in the rings, these objects might normally be difficult to find. However, their presence is betrayed by the large tell-tale `propeller’ structures they generate in the ring material on either side of them. Such features had been found in a different ring locale earlier in the mission but those were much smaller, harder to see, and so numerous that there was no hope of following any one of them. The new propellers, and the moonlets that create them, are some ten times larger and much easier to identify and follow from image to image and year to year.

What is outstanding about these new findings is the insight they ultimately will provide into the early stages of solar system formation, when growing planets become large enough to open gaps in the ring material around them and ultimately truncate their own growth.

To learn more, go to …

http://ciclops.org

http://www.ciclops.org/view_event/137/Propellers_Tracked_for_Years?js=1

… and read all about it.

You may find it amusing that these large propellers have unoffically been named after famous aviators. Those flight enthusiasts among you will recognize Bleriot, Earhart, Santos-Dumont, and others.

(A press release on the new results can be found below. For those of you who would like to read the paper, here is the link: http://arxiv.org/abs/1007.1008 )

Enjoy,

Carolyn Porco
Cassini Imaging Team Leader
Director, CICLOPS
Space Science Institute
Boulder, CO

http://ciclops.org

http://twitter.com/carolynporco

http://www.facebook.com/pages/Carolyn-Porco/116163229386