Astronomy is enjoying a golden age and the W M Keck Observatory is a world leader in cosmic exploration. With generous support from Rob and Terry Ryan, Keck Observatory invites you to take a journey beyond this world to the frontiers of discovery. Your guides are Keck’s astronomers. They will bring you a rich and varied Universe and an evening filled with beauty, drama, mystery and surprise.
Tom Soifer is professor of physics at the California Institute of Technology and the Director of the Spitzer Science Center. He is also the Chair of the Division of Physics, Mathematics and Astronomy at Caltech and a member of the Board of Directors of the W. M. Keck Observatory. The Spitzer Space Telescope is NASA’s latest Great Observatory, designed to explore the infrared portion of the electromagnetic spectrum. Spitzer was launched in August of 2003. In his talk, Soifer will describe some of the most exciting results from the Spitzer mission, among its many discoveries have been measuring the thermal emission and spectra from hot Jupiters orbiting other stars, finding “Fullerene (buckyball)” molecules in space, observing prebiotic molecules in galaxies seen less than 3 billion years after the big bang, and measuring the masses of the most distant and youngest galaxies known.
There is no charge for admission to any events in the Makana series.
Astronomy is enjoying a golden age and the W M Keck Observatory is a world leader in cosmic exploration. With generous support from Rob and Terry Ryan, Keck Observatory invites you to take a journey beyond this world to the frontiers of discovery. Your guides are Keck’s astronomers. They will bring you a rich and varied Universe and an evening filled with beauty, drama, mystery and surprise.
Tom Soifer is professor of physics at the California Institute of Technology and the Director of the Spitzer Science Center. He is also the Chair of the Division of Physics, Mathematics and Astronomy at Caltech and a member of the Board of Directors of the W. M. Keck Observatory. The Spitzer Space Telescope is NASA’s latest Great Observatory, designed to explore the infrared portion of the electromagnetic spectrum. Spitzer was launched in August of 2003. In his talk, Soifer will describe some of the most exciting results from the Spitzer mission, among its many discoveries have been measuring the thermal emission and spectra from hot Jupiters orbiting other stars, finding “Fullerene (buckyball)” molecules in space, observing prebiotic molecules in galaxies seen less than 3 billion years after the big bang, and measuring the masses of the most distant and youngest galaxies known.
There is no charge for admission to any events in the Makana series.
Four previous times we have attempted to do this, hold a star party for the students of Waikoloa Elementary School. Four times it has been either cloudy, or outright raining. Yes, raining in one of the driest areas of the island, a place that gets, maybe, ten inches of rain each year.
We even had clear skies!
It was a great event, perfect skies, several big telescopes, and hundreds of eager eyes.
Students of Waikoloa Elementary School enjoying the night with Mr. OEarly in the evening I was worried that it was all for naught. About 7:30pm we were all set up and had a total of two guests, a mother and her daughter. They were getting a private showing of the sky at my telescope, with good views of Saturn, star clusters and nebulae. But where was everyone else? Classroom announcements had been made. Flyers had been sent home with every student. Two people?
They hit us just after 8:00pm, a steady stream of students and parents drawn to see the sky. I would guess that well over two hundred folks came by the star party. The skies in Waikoloa are wonderful for this sort of thing. Nice and dark, with the summer Milky Way glowing brightly overhead. We slewed from globulars to nebulae, to binary stars. Steady lines of folks waiting to look through each telescope. I have never gotten tired of the reaction when someone sees something spectacular through the eyepiece for the first time.
Cliff used his 24″ ‘scope to hunt down the new supernova in M101, visible as a small star like object at the edge of a faint halo. I was wondering which star was actually the supernova. Examining some photos afterwards I realized we were looking at the correct object. It will be interesting to observe this event over the coming week, as a nearby Type 1A supernova it should get quite bright.
My thanks to the guys from WHAC who supported this event. Mr. O, our school contact had everything perfectly arranged, from the flyers, to insuring the lights and sprinklers were off for the night. It was a great event, I expect we will do this again.
Sounds like someone acting very foolishly has pointed a green laser at aircraft around the Hilo airport. Thanks to Baron for noting the HPD press release on the issue. I wonder if there is someone out there who is unaware that aiming a laser at an aircraft is a violation of federal law.
Green lasers in use at the Mauna Kea VIS nightly observing with the Milky Way high overheadGreen lasers have been in the news quite a bit over recent years, ever since they became inexpensive enough that people buy them on a whim. Lasers in the under 100mW range used to cost hundreds of dollars, can now be ordered on-line for less than fifty dollars. There have been multiple incidents of these lasers pointed at commercial and law enforcement aircraft. Fortunately the usual result is simply distraction for the pilot and no accidents have been reported from laser interference with flight operations.
These lasers are also immensely useful. At the VIS and other local star parties we use green lasers to point out the constellations and to educate our visitors about the sky. There is nothing like being able to point out a specific star, nebula or galaxy directly, you can instantly connect an entire audience with the sky without the usual confusion. Friday night it was a green laser that served as a link to the stars when I used it on the patio of the Mauna Kea VIS.
I use a laser under 30mW, bright enough to be seen by a large crowd, as well as being visible with a bright Moon in the sky, but with a low enough power to be reasonably safe. Above about 50mW these laser pointers become much more dangerous as the laser can inflict injury to the eye faster than you can blink and turn away. Fortunately there is almost no air traffic over Mauna Kea making this a place where you can use the lasers with little worry. Another personal rule I follow is to never let kids handle this laser, even though they always clamor to see this bright wonder of technology.
I can only hope this issue does not attract the attention of our reactionary county council, they have a tendency to ban anything that even seems dangerous. This would be another classic case of one stupid person creating problems for those of us who use a technology responsibly.
Last night was the sort of evening we love, and the reason we volunteer at the Mauna Kea Visitor Information Station. One of those nights where the stars seem close enough to touch, we bring them within reach of those who came to the mountain to learn about the universe.
The Mauna Kea VIS at night with a crowd at the telescopesConditions were near perfect, a dark, clear sky with no Moon, it would rise later. Not only was it dark, but the air was steady, allowing nice high magnification views of Jupiter and other objects. The air was still, it was cold, but without the wind that can make conditions miserable at 9,200ft. The result was a beautiful night that everyone cold enjoy to the fullest.
Joining us were visitors from around the world, I met people speaking German, Spanish and Czech, a British family living in Japan, and more. About fifty people were to be found on the patio when I did the evening star talk. Not only did they come, but they came with curious minds and a will to learn. The questions came from all sides, fast and furious, a constant stream of information.
With such beautiful sights in the telescope to see, the questions just come naturally. I used a C-14 on the Astro-Physics mount to jump from object to object, the Swan Nebula, the globular cluster of M22, the Andromeda Galaxy, the Wild Duck Cluster, the Ring Nebula, the Dumbell Nebula, Alberio. Everything looked so nice that even as jaded observer, I found myself lingering at the eyepiece to enjoy the view.
The evening was a series of personal conversations with one group or family. I would try to use little vignettes to put the knowledge in context, the shape and size of our galaxy, or the story of star birth and death. Trying to convey, in a few minutes, a little glimpse of a bigger picture and not just a mess of gee-whiz information. Sometimes this works, and you are rewarded with a moment of connection, where your audience suddenly understands.
Waimea was living up to reputation with a gusty wind and blowing mist. But this did little to dampen the Waimea Planet Walk sponsored by Keck and CFHT Observatories. A steady stream of parents and kids walked the length of the main street to visit the booths representing a scale model of the solar system.
Keck Observatory’s Ashley Yeager answers questions about the Sun at the Waimea Planet Walk
The Sun and the inner solar system… Mercury, Venus Earth and Mars, all occupied the lawn directly in front of the Keck lobby. Each location was measured properly to achieve the correct position, each booth had a scale model of the planet to correctly interpret the scale of the entire solar system. This meant the Sun was about 8 inches (20cm) in diameter and the Earth a small dot mounted to a piece of wood. In the far corner of the Keck lawn, several hundred feet from the Sun, sat Jupiter represented by a 1/2-inch (1cm) ball bearing.
To visit the remainder of the solar system it was necessary to walk down Mamalahoa highway. Saturn sat in the upper corner of the KTA parking lot, beside the historic cemetery. Uranus was located in the lower corner of the KTA parking lot. Neptune in the park across the street from the library. At the end of the walk, Pluto and the rest of the TNO’s in the lawn of CFHT.
Everyone, volunteers and guests, seemed to be having a great time learning. All up and down the street walked parents and kids from station to station. It is always interesting to see the entire solar system represented to scale like this, even if you have seen it before. The experience is the first step to seeing just how big space is…
How bright a laser beam is needed to allow good public presentations and a good astronomy education experience? In the United States legal green lasers are limited to 5 milliwatts (mW) by the Food and Drug Administration. Many of the lasers sold as 5mW are actually 3-4mW as it is necessary to stay below that limit if you wish to import the laser into the United States or to sell the laser across state lines. 5mW units are fine if you are under fully dark skies, but often you are not, there are city lights, or moonlight and the 5mW beam ceases to be usably visible. This is worse if you are working with a larger group and the distance from the presenter is larger, also making the beam less visible. In practice I have found a beam in the 20-30mW range is about ideal. These lasers are available from a number of sources for around $100. Good visibility in moonlight, good visibility in light polluted surroundings and good large group utility. But importantly, not powerful enough to be truly dangerous.
Deb pointing out the star βPhoenicis to VIS volunteer Joe McDonoughWhere does the 5mW limit come from? The FDA, being a very conservative organization, set the safety threshold at 5mW based on animal and human studies and medical injury data. The 5mW limit is a national standard and applies to interstate or customs transactions, not all states have adopted it. Hawai’i does not appear to have strict laws regarding lasers, licensing or use, so my 30mW unit is legal. This contrasts with my previous home in Arizona, which is more typical of many states. The use of a class IIIb device was subject to licensing, training requirements, and yearly fees. The agency responsible being the Arizona nuclear regulatory office. Sheer bureaucratic overkill that made it practically impossible to legally use a device in the power range I needed, just a few milliwatts over the limit. I am always surprised there is no intermediate class, that a 20-30mW device is classed with devices of up to half a watt, devices that are quite dangerous.
How do I come up with the 20-30mW number as being relatively safe? Being an engineer I understand safety margins and over specification and figured there must be a compromise. The trick was to find undistorted data, without the bias of overcautious bureaucrats. The data is out there on the web, but took some digging to find, many medical journal articles are hidden behind subscription services. Fortunately there are sources like PubMed that are freely and publicly accessible. Eventually I found and read several very informative papers on lasers and eye damage, looked at pictures of laser damage on monkey retinas and looked a damage done by visible lasers in the same sort of power class as those available for public work. I was surprised by actual human damage studies, done on patients who were having eyes removed due to conditions like cancer, where the researcher could do damage without harming the patient. What I was looking for was just what level of laser radiation is dangerous in practical use.
Green lasers in use at the Mauna Kea VIS nightly observing with the Milky Way high overheadThe conclusion I came to was that a 20-30mW unit could cause damage, but was not excessively risky. The data in the papers showed you could generate damage to a retina with even a 5mW device given a long (60s) exposure. But there were a lot of caveats, the beam had to be well focused, the eye could not be moving and it had to be focused for a substantial length of time. In reality a number of things protect the human eye, the first is the fact that the eye is constantly moving, this spreads the power over more than one spot, not allowing cumulative damage at one site. The second is that a bright visible laser will initiate a blink reflex, keeping any exposure in the tens of milliseconds time scale. To prevent these protective effects the tests in the references were sometimes done with anesthetized subjects. At the 100mW power level damage occurred with very short exposures and was quite dramatic.
A 20-30mW laser needs to be treated with respect as injury is possible, but no more than any other dangerous tool we use every day. In practice damage with a laser at a sensible power level (20-30mW) would require prolonged exposure (>0.5sec) on a single site on the retina, requiring staring into the beam. The bright green light would elicit both a blink response and an aversion of the head and eye, particularly in a visually dark adapted environment. I would strongly discourage use of any laser 50mW or greater for public astronomy work. Some of the references showed significant damage inflicted with 50mW lasers and sub second exposures. Lasers at all power levels should be kept out of the hands of anyone too young to understand the implications of the danger posed by a laser.
