Sunday, November 23, 2014

Largest Sunspot in 24 Years Returns for 2nd Month


November 21 photograph of  Sunspot AR-2209, the largest sunspot in 24 years!
(Image Source: Alfredo Vidal)

By Glenn A. Walsh

Reporting for SpaceWatchtower

The largest sunspot on our Sun, in nearly a quarter-century, is now rotating back into view for the second month in a row. Actually, it attained the largest sunspot distinction last month, while it appears somewhat smaller this month.

Last month, Sunspot Active Region 2192 (AR-2192)  was more than ten times the size of the Earth, when it rivaled the October 23 Solar Eclipse in prominence. This month, the sunspot, re-numbered AR-2209, is about one-third its original size.

However, last month Sunspot AR-2192 produced six major solar flares, called X-Flares (the strongest magnitude of solar flares), and also some radio blackouts (R-1 to R-3) in late October. The area of the Sun with Sunspot AR-2209 continues to be active, with several intense M-class Solar Flares. A large M5.7-class Solar Flare peaked early last Monday morning (November 17)  at 12:48 a.m. EDT / 5:48 UTC. So, scientists continue to monitor this sunspot region, to watch for additional solar activity that could be directed towards Earth.

Such solar activity as solar flares and Coronal Mass Ejections (CMEs) can adversely affect radio communication, satellites and GPS systems, and in severe cases can disrupt electrical grid systems. In March of 1989, a large solar storm, known as a geomagnetic storm, caused power failures over large sections of the Canadian province of Quebec, while less severe storms occurred in 1921 and 1960 when there were widespread reports of radio disruptions.

However, the largest effects felt on Earth occurred, at the very beginning of the electrical age, in the first couple of days of September of 1859, when ground-based magnetometers recorded one of the largest geomagnetic storms ever. This is known as the "Carrington Event" for English Amateur Astronomer Richard Carrington, who made among the first observations of a major solar flare on September 1 that is associated with a huge CME that led to telegraph system failures, electric shocks to telegraph operators, and even fires in some telegraph offices. The Carrington Event also resulted in Aurora observations throughout the world, particularly in lower latitude locations unaccustomed to such displays.

This-past April, NASA announced that an event possibly similar to the Carrington Event may have missed the Earth in 2012. On 2012 July 23, NASA's STEREO-A spacecraft recorded a huge CME that sped four times faster from the Sun than a normal solar eruption. Fortunately, the Earth was not in the path of this CME, which Daniel Baker of the University of Colorado claimed "might have been stronger than the Carrington Event itself," as was the spacecraft.
 
The Spaceweather Prediction Center of the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA, which also administers the National Weather Service), commented on Sunspot AR-2209 on November 16:


Although not quite as impressive in size, it is still a large region with a complex magnetic structure, and is capable of producing even more X-ray flare activity. It has already produced two M-class flares (R1-Minor radio blackouts), and has only been on the Earth-side of the sun for a couple of days. And, unlike its previous transit, it appears to have coronal mass ejections (CMEs) associated with some of its flare activity.
This could mean an increased probability for elevated geomagnetic storming. Forecasters will be monitoring this region closely over the next week and a half as it makes its way across the visible disk.

Sunspots and large sunspot regions are huge magnetic storms on the visible surface of the Sun's photosphere, some as large or larger than the planet Earth, such as the one now visible on the Sun. Sunspots appear darker than the rest of the Sun's photosphere, often with a black or brown coloration, because they are cooler than the rest of the photosphere, due to convection currents in the sunspot. When a sunspot reaches the Sun's surface, the convection is then inhibited resulting in less heat and consequently lower temperature.

However, sunspots are not cold or even cool. It is the contrast between the cooler sunspots ( at ~ +2,700 to +4,200 degrees Celsius) and the hotter photosphere (at ~ + 5,500 degrees Celsius) that makes the sunspots appear dark. A sunspot, if it could be removed from the Sun, is so hot that it would appear as a mini-star on its own!

The Sun is not solid like the Earth, and it is composed of hot plasma interwoven with magnetic fields. Like the Earth, the Sun does rotate on its axis, and because this rotation is uneven throughout the solar disk, the magnetic fields twist and turn, and when these magnetic fields break the solar surface the result is a sunspot. This is somewhat analogous to how the Earth's axial rotation affects weather systems in our atmosphere. The intense and twisted magnetic fields, which form the sunspot region, are usually the source of solar flares and CMEs. 

Sunspots, particularly the larger ones, sometimes, but not always, appear in pairs (a "leader" first develops, followed by a "follower" or "trailer," with respect to the direction of solar rotation), each with opposite magnetic polarity. The dark central portion of a sunspot is known as the umbra, while the lighter, outer portion of the sunspot is known as the penumbra (a similar naming convention is used for lunar eclipses).

Sunspots usually come in cycles of approximately eleven years (and could actually run anywhere from nine to fourteen years in length). Many more sunspots, often along with solar flares and CMEs, are seen around the peak of the sunspot cycle or Solar Maximum, while many fewer sunspots are seen during the lull portion of the cycle or Solar Minimum. A historical Solar Minimum, known as the Maunder Minimum, occurred from approximately 1645 to 1715, when sunspots were very rare according to solar observers of that time period.

Scientists say the current sunspot cycle, Solar Cycle 24, has reached the Solar Maximum this year, but is one of the lowest Solar Maximums in recent history. However, Sunspot AR-2209 and the 2012 CME are examples of what can happen even during a low Solar Maximum.

Similar "starspots" have been indirectly observed on stars beyond our solar system.

Pittsburgh's original Buhl Planetarium and Institute of Popular Science, which observed its 75th anniversary on October 24, regularly showed sunspots to the public, weather permitting (1941 to 1991), using a rather unique 10-inch Siderostat-type Refractor Telescope. The polar-aligned and horizontally mounted telescope, fed by a first-surface mirror on a sidereal coleostat or siderostat unit driven by a clock-drive motor, projected the solar image on a large projection screen in a heated observing room. Two small circles inscribed on the screen (depicting the size of the Earth) allowed the public to compare the size of sunspots to the size of the Earth, when the telescope used a 65-power or 80-power eyepiece to project the image of the Sun.

More on Sunspots: Link >>> http://en.wikipedia.org/wiki/Sunspot 

More on Solar Flares: Link >>> http://en.wikipedia.org/wiki/Solar_flare 

More on Coronal Mass Ejections: Link >>> http://en.wikipedia.org/wiki/Coronal_mass_ejection

More on the Sun: Link >>> http://en.wikipedia.org/wiki/Sun 

More on the Carrington Event: Link >>> http://en.wikipedia.org/wiki/Solar_storm_of_1859 

More on the Maunder Minimum: Link >>> http://en.wikipedia.org/wiki/Maunder_Minimum

More on Solar Observing at Pittsburgh's original Buhl Planetarium and Institute of Popular Science:
Link >>> http://buhlplanetarium2.tripod.com/

Related Blog Posts ---

Solar Eclipse on Eve of Buhl Planetarium's 75th Anniversary (2014 Oct. 21):

Link >>> http://spacewatchtower.blogspot.com/2014/10/solar-eclipse-on-eve-of-buhl.html


Very Strong Solar Storm Narrowly Misses Earth (2014 May 3):

Link >>> http://spacewatchtower.blogspot.com/2014/05/very-strong-solar-storm-narrowly-misses.html

 

Colossal Sunspot Growing Fast, Solar Storms Possible (2013 Feb. 21):

Link >>> http://spacewatchtower.blogspot.com/2013/02/colossal-sunspot-growing-fast-solar.html

 

Sunspot AR1654 Getting Bigger w/ Solar Flare (2013 Jan. 12):

Link >>> http://spacewatchtower.blogspot.com/2013/01/sunspot-ar1654-getting-bigger-w-solar.html

Enormous Sunspot Could Lead to Solar Flares (2012 May 9):

Link >>> http://spacewatchtower.blogspot.com/2012/05/enormous-sunspot-could-lead-to-solar.html


70th Anniversary: Buhl Planetarium Observatory: (2011 Nov. 19):

Link >>> http://spacewatchtower.blogspot.com/2011/11/70th-anniversary-buhl-planetarium.html

 
Source: Glenn A. Walsh, Reporting for SpaceWatchtower, a project of Friends of the Zeiss.

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Upcoming Event:
DEC. 4 – PUBLIC VIEWING, VIA WEB-CAST, OF 1st NASA TEST LAUNCH
OF NEW ORION DEEP-SPACE VEHICLE AT MT. LEBANON PUBLIC LIBRARY


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Thursday, November 20, 2014

Kickstarter: Lunar Mission One



A British-led consortium has announced an ambitious space mission named Lunar Mission One that plans to land a robotic probe in the southern polar region of the moon in about a decade. The announcement continues a stream of innovative space developments.

The Lunar Mission One is unique, in that the project will be funded by money raised solely through donations from the public. In order to achieve this, the project is using the funding platform Kickstarter to finance the next phase of development. Kickstarter supporters will become inaugural members of the Lunar Missions Club and will be rewarded with a range of involvement, information and rewards including their own “digital memory box”. These memory boxes will eventually go on sale to the general public and all of them will be included in a time capsule to be buried on the moon as part of the mission.

Alongside these individual archives, the project is creating a public archive to go in the capsule: a digital record of life on Earth – of human history and civilisation and a scientific description of the biosphere with a database of species. Publicly owned and accessible to all, this archive is a hugely ambitious plan that could only be resourced by a project of this scale.

The scientific and technological rewards from Lunar Mission One will be many. It is backed by leading space scientists, such as Monica Grady at the Open University and Richard Holdaway at the Rutherford Appleton Laboratory. The mission is planning to land in the southern polar region of the Moon – a feat that has never been achieved before. Also, there is tantalising evidence in the polar regions of the Moon of huge reservoirs of water-ice – potentially delivered by comets and asteroids during 4.5 billion years of the moon’s geological history. Collecting and analysing material from lunar polar regions will contribute to our understanding of the sources of water on Earth.

More - Link >>> http://theconversation.com/british-choose-to-go-to-the-moon-with-kickstarter-crowdfunding-34103

Source: TheConversation.com .

Lunar Mission One Kickstarter Project:
Link >>> https://www.kickstarter.com/projects/lunarmissionone/lunar-mission-one-a-new-lunar-mission-for-everyone?ref=nav_search

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Upcoming Event:
DEC. 4 – PUBLIC VIEWING, VIA WEB-CAST, OF 1st NASA TEST LAUNCH
OF NEW ORION DEEP-SPACE VEHICLE AT MT. LEBANON PUBLIC LIBRARY


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Monday, November 17, 2014

Leonid Meteor Shower Peaks Tonight


Photograph of a meteor during the 2009 Leonid Meteor Shower. (Image Source: Wikipedia.org )

By Glenn A. Walsh
Reporting for SpaceWatchtower

The annual Leonid Meteor Shower peaks tonight, and skywatchers could be treated to 10 to 15 meteors per hour, weather permitting. Of course, with the polar vortex making an early visit to much of the country, sky conditions may not be optimal for skywatching  tonight.

Some people may decide it is just too cold to look for meteors tonight, even if skies are clear. In the Pittsburgh region, the low temperature is predicted to be +13 degrees Fahrenheit / -10.6 degrees Celsius, Monday night--early Tuesday morning. Also, in Pittsburgh winds are predicted to come from the west at 15 to 20 miles-per-hour / 24 to 32 kilometers-per-hour, with possible wind gusts up to 30 miles-per-hour / 48 kilometers per hour; predicted wind chill temperatures could reach 0 degree Fahrenheit / -18 degrees Celsius. And, considering that Pittsburgh is only about 75 miles / 121 kilometers north of the Mason-Dixon Line, areas of the country further north will likely be even colder.

However, if your sky is clear tonight, and it is not too cold, the best time to view meteors is between local midnight and dawn. While the actual meteor shower peak this evening is 6:00 p.m. EST / 23:00 UTC, it is always best to look for meteors after local midnight, when the Earth is actually rotating into the meteor shower.

Meteors from the Leonid Meteor Shower emanate from remnants of Comet Tempel-Tuttle. Leonid Meteor Storms occur once each 33 years (the last one was in 2009), when many meteors are visible. Other years, such as this year, the peak rate of meteors would be about 10 (to possibly 15) meteors per hour, under ideal conditions.

The Leonids are so named because most meteors appear to radiate from the Constellation Leo the Lion. However, during any meteor shower, meteors can appear in any part of the sky at any time.

Telescopes and binoculars are of little use for finding meteors. Such optical devices restrict the field-of-view, thus that you could easily miss a lot of meteors, and the chance that you could observe a meteor with a telescope or binoculars is not very good. The best way to look for meteors is to lie down on the ground, in an area with an unobstructed view of most of the sky. Then, just keep scanning throughout the sky until you see a meteor.

More on tonight's Leonid Meteor Shower, from Scientific American Magazine and Space.com :
Link >>> http://www.scientificamerican.com/article/leonid-meteor-shower-peaks-tonight-how-to-see-it/

More on the Leonid Meteor Shower:
Link >>> http://en.wikipedia.org/wiki/Leonid_meteor_shower

More on Comet Tempel-Tuttle:
Link >>> http://en.wikipedia.org/wiki/55P/Tempel-Tuttle

Source: Glenn A. Walsh, Reporting for SpaceWatchtower, a project of Friends of the Zeiss.

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Saturday, November 15, 2014

New Laser System Could Provide Mini Atomic Clocks


The Master Atomic Clock ensemble at the U.S. Naval Observatory in Washington DC, which
provides the time standard for the U.S. Department of Defense and provides precise time for
the general public at: Link >>> http://tycho.usno.navy.mil/cgi-bin/timer.pl
(Image Source: Wikipedia.org )

By MIT, Jennifer Chu

What time is it? The answer, no matter what your initial reference may be — a wristwatch, a smartphone or an alarm clock — will always trace back to the atomic clock.

The international standard for time is set by atomic clocks — room-sized apparatuses that keep time by measuring the natural vibration of atoms in a vacuum. The frequency of atomic vibrations determines the length of one second — information that is beamed up to GPS satellites, which stream the data to ground receivers all over the world, synchronizing cellular and cable networks, power grids and other distributed systems.

Now, a group at MIT and Draper Laboratory has come up with a new approach to atomic timekeeping that may enable more stable and accurate portable atomic clocks, potentially the size of a Rubik’s cube. The group has outlined its approach in the journal Physical Review A.

While chip-sized atomic clocks (CSACs) are commercially available, the researchers say these low-power devices — about the size of a matchbox — drift over time, and are less accurate than fountain clocks, the much larger atomic clocks that set the world’s standard. However, while fountain clocks are the most precise timekeepers, they can’t be made portable without losing stability.

The most accurate atomic clocks today use cesium atoms as a reference. Like all atoms, the cesium atom has a signature frequency, or resonance, at which it oscillates. Since the 1960s, one second has been defined as 9,192,631,770 oscillations of a cesium atom between two energy levels. To measure this frequency, fountain clocks toss small clouds of slow-moving cesium atoms a few feet high, much like a pulsed fountain, and measure their oscillations as they pass up, and then down, through a microwave beam.

Instead of a microwave beam, the group chose to probe the atom’s oscillations using laser beams, which are easier to control spatially and require less space — a quality that help in shrinking atomic clock apparatuses. While some atomic clocks also employ laser beams, they often suffer from an effect called “AC Stark shift,” in which exposure to an electric field, such as that produced by a laser, can shift an atom’s resonant frequency. This shift can throw off the accuracy of atomic clocks.

To avoid this problem, most standard fountain clocks use microwave beams instead of lasers. However, Kotru and his team looked for ways to use laser beams while avoiding AC Stark shift.

In laser-based atomic clocks, the laser beam is delivered at a fixed frequency and intensity. Kotru’s team instead tried a more varied approach, called Raman adiabatic rapid passage, applying laser pulses of changing intensity and frequency — a technique that is also used in nuclear magnetic resonance spectroscopy to probe features in individual molecules.

“For our approach, we turn on the laser pulse and modulate its intensity, gradually turning it on and then off, and we take the frequency of the laser and sweep it over a narrow range,” Kotru explains. “Just by doing those two things, you become a lot less sensitive to these systematic effects like the Stark shift.”

In fact, the group found that the new timekeeping system suppressed the AC Stark shift by a factor of 100, compared with a conventional laser-based system.

More - Link >>> http://www.laboratoryequipment.com/news/2014/11/pocket-sized-atomic-clocks?et_cid=4262739&et_rid=544605860&location=top

Sources: Massachusetts Institute of Technology, LaboratoryEquipment.com .

Related Blog Posts ---

New U.S. Atomic Clock World's Most Accurate (2014 April 26):
Link >>> http://spacewatchtower.blogspot.com/2014/04/new-us-atomic-clock-worlds-most-accurate.html

Even More Accurate Atomic Clock (2014 Jan. 27):
Link >>> http://spacewatchtower.blogspot.com/2014/01/even-more-accurate-atomic-clock.html

 

Laser Pulses Create More Accurate Atomic Clocks (2013 June 21):
Link >>> http://spacewatchtower.blogspot.com/2013/06/laser-pulses-create-more-accurate.html


2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Thursday, November 13, 2014

Supersonic Laser Propulsion

The effectiveness of current laser-propulsion techniques is limited by the instability of supersonic gas flow, caused by shock waves that “choke” the inlet of the nozzle, reducing thrust. Those effects can be reduced with the help of laser ablation, redirecting the plasma plume so that it flows close to the interior walls of a supersonic nozzle and significantly improving the overall thrust. Courtesy of Y.Rezunkov/IOIE The effectiveness of current laser-propulsion techniques is limited by the instability of supersonic gas flow, caused by shock waves that “choke” the inlet of the nozzle, reducing thrust. Those effects can be reduced with the help of laser ablation, redirecting the plasma plume so that it flows close to the interior walls of a supersonic nozzle and significantly improving the overall thrust. Courtesy of Y.Rezunkov/IOIE





 

 

 

 

 

 

 

 

 

 

 

 

Scientists and science fiction writers alike have dreamed of aircraft and spacecraft that are propelled by beams of light rather than conventional fuels. Now, a new method for improving the thrust generated by such laser-propulsion systems may bring them one step closer to practical use.

 

Currently, the maximum speed of a spacecraft is limited by the amount of solid or liquid fuel that it can carry. Achieving higher speeds means that more fuel must be burned — fuel that, inconveniently, has to be carried by the craft and hefted into space. These burdensome loads can be reduced, however, if a laser — one located at a remote location, and not actually on the spacecraft — were used to provide additional propulsive force.

 

A number of systems have been proposed that can produce such laser propulsion. One of the most promising involves a process called laser ablation, in which a pulsed laser beam strikes a surface, heats it up, and burns off material to create what is known as a plasma plume. The outflowing of that plasma plume — essentially, exhaust — generates additional thrust to propel the craft.

 

More - Link >>> http://www.scientificcomputing.com/news/2014/10/supersonic-laser-propelled-rockets-may-enable-aircraft-exceed-mach-10?et_cid=4240734&et_rid=544605860&location=top 

 

Sources: The Optical Society, ScientificComputing.com .

 

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >

Tuesday, November 11, 2014

WWII Medals Return to Earth in Time for Veterans' Day

Astronaut Reid Wiseman tweets from space | Video
Photograph of Ralph Sweitzer's Purple Heart and
Bronze Star medals from World War II, which
flew with his great-nephew, NASA Astronaut Reid
Wiseman, on the International Space Station.
(Image Source: E.W. Scripps Co.)

By Glenn A. Walsh
Reporting for SpaceWatchtower

Just in time for Veterans' Day, two World War II medals returned to Earth yesterday from spending several months on the International Space Station. The medals belong to 94-year-old Ralph Sweitzer of Vero Beach, Florida and were included in the small box of possessions taken aboard the Space Station by Mr. Sweitzer's great-nephew, NASA Astronaut G. Reid Wiseman.

U.S. Navy Commander Wiseman, Flight Engineer for Space Station Expedition 41, returned to Kazakhstan yesterday at 9:58 a.m. (Nov. 9, 10:58 p.m. EST / Nov. 10, 3:58 UTC) along with Expedition 41 Commander Max Suraev of the Russian Federal Space Agency and Alexander Gerst of the European Space Agency.

Back in May, just before Commander Wiseman prepared for launch to the Space Station, he asked his great-uncle, Ralph Sweitzer, to allow him to take two of Mr. Sweitzer's several World War II medals into outer space: Mr. Sweitzer's Purple Heart and Bronze Star.

Mr. Sweitzer fought in the Battle of the Bulge in Germany in 1945, near the end of the War. Mr. Sweitzer and two other soldiers were pinned-down in a fox-hole, enduring German bombing. Mr. Sweitzer was the only one who survived the ordeal, but he was badly injured.

During Commander Wiseman's time on the Space Station, he and the other crew members participated in research focusing on Earth remote sensing, advance manufacturing, and bone and muscle physiology studies. Human health management for long duration space travel was a key focus, as NASA and Russia prepare for two astronauts to spend an entire year on the Space Station beginning in 2015.

Commander Wiseman took two spacewalks outside of the Space Station. The first, with Mr. Gerst, was to relocate a failed pump module and configure the station for upcoming additions. The second spacewalk was completed with fellow NASA Astronaut Barry Wilmore.

During the mission on the Space Station, Commander Wiseman became well known to followers of social media for his many Twitter posts and his many photographs taken of Earth and celestial objects.

This was the first flight in space for Commander Wiseman, who received a Bachelor of Science degree in Computer and Systems Engineering from Rensselaer Polytechnic Institute in 1997 and a Master of Science degree in Systems Engineering from Johns Hopkins University in 2006.


More about Commander Wiseman: Link >>> http://www.jsc.nasa.gov/Bios/htmlbios/wiseman.html

Source: Glenn A. Walsh, Reporting for SpaceWatchtower, a project of Friends of the Zeiss.

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


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Glenn A. Walsh, Project Director,
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Electronic Mail - < gawalsh@planetarium.cc >
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Saturday, November 8, 2014

CMU Moon Robot to Send Virtual Reality Back to Earth

Daniel  Shafrir and robot Andy Daniel Shafrir hopes Andy can transform education about space.



Scientists at Carnegie Mellon University have developed a robot which they plan to land on the Moon to act as eyes for Earth-bound space enthusiasts.

The scientists from Carnegie Mellon have teamed up with space firm Astrobotic to compete for the Google Lunar XPrize, which requires a team to land a robot on the Moon, move it 500 meters and send back video to Earth.

The robot has already been shown to potential investors, including Apollo 9 astronaut Rusty Schweickart.

It works in tandem with an Oculus Rift virtual reality headset.

"The vision was simple - let anyone on Earth experience the Moon live through the eyes of a robot," explained team leader Daniel Shafrir.

"We weren't just going to go to the Moon. We are going to bring the Moon back," he added.

The telepresence robot, nicknamed Andy after university founder Andrew Carnegie, can be controlled by an operator's head.

Working with games designer Ben Boesel and Slippery Rock University Planetarium Director Dan Arnett, the team put Andy through his paces in a demo last month.

Slippery Rock University
Slippery Rock University
More - Link >>> http://www.bbc.com/news/technology-29704953

Source: British Broadcasting Corporation.

2014: 75th Year of Pittsburgh's Buhl Planetarium Historic Zeiss II Planetarium Projector at Pittsburgh's original Buhl Planetarium and Institute of Popular Science.


Want to receive SpaceWatchtower blog posts in your inbox ?
Send request to < spacewatchtower@planetarium.cc >..

gaw

Glenn A. Walsh, Project Director,
Friends of the Zeiss < http://buhlplanetarium.tripod.com/fotz/ >
Electronic Mail - < gawalsh@planetarium.cc >
SpaceWatchtower Blog: < http://spacewatchtower.blogspot.com/ >
Also see: South Hills Backyard Astronomers Blog: < http://shbastronomers.blogspot.com/ >
Barnestormin: Writing, Essays, Pgh. News, & More: < http://www.barnestormin.blogspot.com/ >
About the SpaceWatchtower Editor / Author: < http://buhlplanetarium2.tripod.com/weblog/spacewatchtower/gaw/ >
SPACE & SCIENCE NEWS, ASTRONOMICAL CALENDAR:
< http://buhlplanetarium.tripod.com/#news >
Twitter: < https://twitter.com/spacewatchtower >
Facebook: < http://www.facebook.com/pages/SpaceWatchtower/238017839577841?sk=wall >
Author of History Web Sites on the Internet --
* Buhl Planetarium, Pittsburgh:
  < http://www.planetarium.cc >
* Adler Planetarium, Chicago:
  < http://adlerplanetarium.tripod.com >
* Astronomer, Educator, Optician John A. Brashear:
  < http://johnbrashear.tripod.com >
* Andrew Carnegie & Carnegie Libraries:
  < http://www.andrewcarnegie.cc >
* Civil War Museum of Andrew Carnegie Free Library:
  < http://garespypost.tripod.com >
* Duquesne Incline cable-car railway, Pittsburgh:
  < http://inclinedplane.tripod.com >
* Public Transit:
  < http://andrewcarnegie2.tripod.com/transit >