I'm Your Moon

The logical followup to my post about the Guitar Nebula is something with actual guitar in it. Thankfully I have a perfect astronomy song to kick off your weekend.

As I mentioned earlier in the week we are coming up on the three year anniversary of the IAU's decision to demote Pluto from planet to dwarf planet.

Shortly after that event Jonathan Coulton wrote this song. He explains it better than I can. So watch and listen to this clip from his DVD BEST. CONCERT. EVER.

I know of lots of love songs that mention our moon, but this is the only one that I know of that was written as one celestial body singing to another. It is really masterful and the most creative thing I know of to come as a result of the IAU's decision. You should enjoy this song no matter which side you are on of the Pluto dwarf planet debate.

Tip of the dome to Jeff P. who alerted me to this.

Guitar Hero

The supernova explosion of a star is sometimes symmetrical and sometimes not. When the explosion is not symmetrical some of the energy of the explosion gives the resulting neutron star a kick sideways. The results of that can be spectacular.

The Guitar Nebula is indeed a spectacular example of what can happen when a neutron star gets a sideways kick:


Back in 1992 a group of researchers from Cornell University used the Hale Telescope at Palomar Observatory to discover a unique nebula associated with a high-velocity spinning neutron star (also called pulsar) known as PSR 2224 + 65. This pulsar is flying through a gas cloud and producing shock wave in the gas very much like the wake of a boat moving through water. The result is the Guitar Nebula.

The pulsar is flying through a gas cloud at an amazing speed of about 800 km/s (1.8 million miles per hour!), fast enough that it will eventually escape the Milky Way galaxy. It is also fast enough that it is possible to watch the neutron star move in just a few years time.

Given the Guitar Nebula's distance (about 6,500 light years away, in the constellation of Cepheus) and apparent size in the sky (1 arc minute) astronomers estimate that the neutron star has been traveling for 300 years.

Palomar in Ads - II

It has been a while since I posted an advertisement featuring Palomar Observatory.

This full-page magazine ad for Kodak film ran in back in 1948 or 1949 sometime after the dedication of the 200-inch telescope.

Kodak produced the photographic plates that were used at Palomar for years. The last photographic plate shot with the Hale Telescope was taken in 1989. We continued to use Kodak plates for the Second Palomar Observatory Sky Survey, performed with the 48-inch Schmidt (aka the Samuel Oschin Telescope) all the way up to the year 2000.

The first CCD photography at Palomar began in the 1970s and everything is 100% digital now. Of course our reach into space is a lot farther now than the "billion light years" quoted in the ad.

Rawhide

People often ask me about the cattle guards and the cattle signs up on Palomar Mountain. They are often astonished to hear that there are real, live cows up here. Once in a while the evidence is obvious:

About twice a year the ranchers on Palomar Mountain put on a real cattle drive. The last one took place just about 2 weeks ago. I managed to miss it completely, but did see the after affects lying in the road to the observatory.

Thankfully, the folks at HPWREN captured the above image on their way home after a meeting with me and made it their Image of the Week for July 18, 2009.

First Light for Cosmic Web Imager

Back at the end of May Cosmic Web Imager, the newest instrument for the 200-inch telescope, got a test fit. Actually, back then it wasn't even built. Last night the finished instrument achieved first light.

The Cosmic Web Imager (CWI) was built to help astronomers explore the intergalactic medium. It will be used to map ultraviolet emissions from the low surface brightness universe and tell us where gas is located out between galaxies. Up until now, astronomers have had narrow keyhole-like views into the universe where they have been able to map intergalactic matter. By studying how the light from a distant quasar is affected as it passes through clouds of matter located between Earth and the quasar, astronomers have been able to map the location of these clouds, but only those in the same line of sight as a quasar. CWI should provide astronomers with a much richer view of where this material is and provide new insights on the formation of galaxies and the presence of dark matter.

The image above shows the new instrument mounted in the Hale Telescope's Cassegrain cage. Congratulations to Chris Martin and his team at Caltech for bringing this new instrument to life! They have 2 more nights of commisioning before the instrument returns again in October.

Daytime Open Dome

It isn't often that the dome of the 200-inch telescope is open in the daytime. Normally, the dome is sealed up tight so that we can maintain nighttime temperature inside the dome. This keeps the telescope and its instrumentation at the temperature it will be used during the night.

Once in a while, if there has been a big swing in temperature, we need to open in the day to allow for the telescope and dome air to equalize in temperature with the outside air.

Today, we opened the dome to allow our crew to perform maintenance on the rails that the dome shutters ride on.

For me that meant that I had another opportunity to take photos of the Hale Telescope in lighting that is different from what is normally found in the dome. Below are some of my favorite photos from today. Remember you can click on them to enlarge the view.

Here is the view from the catwalk south of the telescope with the dome fully open and the shutters pointed just east of north:


This image is from the catwalk, positioned just south of west of the telescope, with shutters fully open:

For scale, note the person walking across the dome floor. He is a little to the left of the telescope and a bit further away.

It seems that my favorite lighting is with the shutter only partially open. That way there is some natural light, but the lights within the dome add some color to the view. For this photo I was again on the catwalk, but directly southwest of the telescope. As you can see the shutter is just cracked open a little bit:


This photo was taken from the east side of the telescope, directly above the visitors' gallery. It was also taken with the dome just barely open:


This shot was taken from the dome floor and is perhaps my favorite from this morning. The shutter is cracked open a little bit giving a nice mix of natural and artificial lighting:

In this shot you can see what looks like a human figure on the observing floor. That is actually one of the heated electric flight suits that the astronomers used to wear when riding in prime focus. We have it on display for our many visitors.

Finally, the experience would not be complete without showing you the view from outside the dome. This was taken along the visitors path that leads up to the dome:


The time to perform the maintenance was limited because we do not allow direct sunlight to fall onto the telescope. When the Sun is high enough in the sky it is time to close the dome. Because of that the work is not yet finished.

We do expect to have the dome open again on Thursday, July 30 from about 8 to 10 a.m. PDT. It might make for a nice time to plan a visit or to look in via our webcam.

Video Tour pt. 2

Here is part 2 of my tour with Thunderf00t. This one covers aluminizing the 200-inch mirror. You can watch it here or embedded below.



You might also enjoy his video visit to Mt. Wilson Observatory.

Eris Anniversary

Four years ago today the discovery of dwarf planet Eris was announced. Eris was found using Palomar's Samuel Oschin Telescope. Of course back then it didn't even have a proper name. Eris helped to push the issue of Pluto's planetary status forward and nearly three years ago the International Astronomical Union (IAU) decided to create the new dwarf planet category and put both Pluto and Eris into to it (along with the asteroid Ceres).

The IAU meets again this summer. While the issue of Pluto may not come up again there, it certainly hasn't gone away. NewScientist has as story Is Pluto a planet after all? that is worth reading if you are interested in this issue.

Also Mike Brown, the discoverer of Eris, has some book reviews on his blog that cover the events related to the whole dwarf planet / Pluto issue. Click on over to see what he has to say about The Pluto Files: The Rise and Fall of America's Favorite Planet by Neil DeGrasse Tyson and The Hunt for Planet X: New Worlds and the Fate of Pluto by Govert Schillng. Both books are on my reading list, but I haven't gotten around to them yet.

Video Tour pt. 1

Last week I got to meet Thunderf00t, a YouTube broadcaster with a channel known as beautyinthuniverse. I gave him an inside look at the Hale Telescope and you can see his first of two videos here or below.

Lost History?

Years ago the late Walter Cronkite had a TV series called You Were There. In the show important events from history were recreated but with modern reporters on hand to ask questions and bring the accounts to listeners (when it was on radio) and to viewers (when it was on TV). The first run of the series ended before I was born, but it came back in the early 70s on Saturday mornings and at least once I turned my head away from the Bugs Bunny Roadrunner Show to watch Walter Cronkite as he brought me back to 1609-10 and the discoveries Galileo made with his new telescope.

It was a great show and just perfect for me as I was already very interested in astronomy. The show attempted to capture and show in a modern format what could not have been captured as it happened.

Thankfully, in modern times we have many ways of recording history as it happens. It has been my pleasure working at Palomar to receive examples of this from the observatory's past. Many photos and other accounts have come my way in recent years and each of them is a treasure.

June 3, 1948 was the dedication of the 200" telescope, naming it for the late George Ellery Hale.

On the reviewing stand was Ira Bowen. In an oral history recorded 21 years later this is part of what he had to say about that day:

We had a thousand people seated on the main floor of the dome, with a speakers’ stand to the west. We could get in a thousand chairs, we found, on the main floor without using the balcony; and they were practically all filled.

The photographers were out in force that day and many fine photos of the day still exist and should continue to for years and years to come. But the photos taken that day reveal that moving pictures and audio recordings were made too. Where are they?

A closer look at the photo above reveals a movie camera on the observing floor pointed at the speakers' stand:


In a second photo you can see that there was also a movie camera on the catwalk:



Here's the chairman of the Board of Trustees of the California Institute of Technology, Mr. James R. Page, giving one of the speeches at Palomar on June 3, 1948:


In front of him are a few microphones, including one from KFI in Los Angeles. KFI was also on hand the day the 200-inch mirror made its way up Palomar Mountain. You can read about it here. One of the observatory's docents recently contacted KFI to see if any tapes remain from either event. It seems that they are quite likely lost.

KWKW from LA was also on hand and from this photo they obviously made a recording of the speeches given during the dedication.

Google tells me that they are now a Spanish language station. They have not yet been contacted, but who knows what may have been tossed out duirng the conversion.

I know that the producers of The Journey to Palomar documentary performed an extensive search and came up empty handed, but it may be that somone out there knows where some of these things are. If so, I would certainly love to be in contact with them.

It would be a terrible tragedy if they were recorded for history and then lost. The media was there. The people and their voices should be heard. Walter Cronkite would have wanted it that way.

The New World's Largest Telescope

On Friday, July 24 the 10.4-meter Gran Telescopio Canarias (GTC) or Great Canary Telescope will be inaugurated. The GTC is slightly larger than Hawai'i's twin 10-meter Keck telescopes and will now hold the title of world's largest optical telescope.

I had the chance to visit the telescope when I attended the Starlight Conference in 2007.

Unfortunately I did not have a wide-angle lens with me.

That's the view from the observing floor looking up into the dome and the telescope's primary mirror.


Unlike the Hale's monolithic mirror the GTC's primary mirror (like those at Keck) is made up of 36 segments. The segments are just over 3 inches (8 cm) thick. Each of the 36 mirrors must remain properly aligned. Everything that's below the mirror segments in the photo above (except what is red) is part of the GTC active optics system which continuously adjusts the position of the segments to keep them perfectly aligned. Palomar's 200-inch mirror has a primitive version of the same thing. In our case the mirror has 36 supports which are passively controlled. As the telescope moves to a different position they gravitationally readjust their push or pull on the glass to keep it in the proper shape.

Last Saturday Night

I love the summer Milky Way. This is how it looked the evening of July 18th during a star party for the Friends of Palomar Observatory.

Yes, Palomar still has dark skies, but the affects of sky glow are keenly felt by those performing research and those who want to enjoy the Milky Way on a summer evening. That is why working to fight light pollution is so vital.

TMT Goes to Hawai'i

It was announced yesterday that the Thirty Meter Telescope's board of directors has selected Mauna Kea on the Big Island of Hawai'i as the site for the project.

Rendering of the TMT from Todd Mason Graphics

When completed in 2018 the TMT will have a primary mirror made up of 492 segments that will gather 36 times more light than Palomar's Hale Telescope.

I have not heard when the project is expected to begin construction, but they still need to obtain a Conservation District Use Permit from the Hawaiian Department of Land and Natural Resources.

40 Years Ago

Graffiti on the 200-inch Mirror

Once every 18 - 24 months the 200-inch mirror is pulled from the telescope to be re-aluminumized. When that happens the old coating of aluminum is removed and the mirror's honeycombed underside is revealed.

Apparently on July 20, 1936 someone wrote on the underside of the glass. Have a look at this unusual looking down through the glass to the underside:


The photo was reversed to make it easier to read the writing. I can't quite make out the first line. The second one reads:

July 20 - 1936

and the third says:

Russ Allen

and I am not sure about the 4th. Any ideas?


Of course, this isn't the only example of graffiti on the 200-inch mirror.

Remembering Apollo, a Comet Crash & Eugene Shoemaker

Yesterday, July 16th was the 40th anniversary of the liftoff of the Apollo 11 Mission. NPR had a wonderful story on the role of the USGS's astrogeology team in the training of the Apollo astronauts. Click on over to see and hear One Small Town's Big Role In The Apollo Missions.

Some of the time in the story is devoted to Eugene Shoemaker, the father of astrogeology. Gene was an astronaut hopeful, but a medical condition kept him grounded, but without his hard work and guidence the Apollo missions would not have been as scientifically productive as they were. If you visit the NPR page, in addition to listening to or reading the story, be sure to watch the USGS film on rocketpacks. It is fantastic.

Running the story on July 16th, not only marked the Apollo 11 anniversary, but also the anniversary of the first impact of the fragments of Comet Shoemaker-Levy 9 with Jupiter back in 1994. Comet Shoemaker-Levy 9 was discovered at Palomar in 1993 with the 18-inch Schmidt.


The impact of the cometary fragments with Jupiter was one of more important astronomical events of the 20th Century. This animation gives a rapid look at the comet crashes which lasted from July 16 - 22, 1994. The animation does indeed give a proper sense of the affects of the impacts that resulted in Jupiter's atmosphere. Many of the dark clouds that appeared from the impacts were larger than Earth.



If you want to learn more about the amazing life of Eugene Shoemaker, I highly recommend David H. Levy's book Shoemaker By Levy. It is a wonderful, personal look at Gene and his scientific career.

Haumea in the News

Dwarf planet Haumea was discovered at Palomar by Mike Brown and his colleagues back in 2003. Earlier this week the Ethiopian Review put out a story on it: The Weirdest Object in the Solar System. Also, Centauri Dreams, the news forum of the Tau Zero Foundation, posted Fast Orbiter to Haumea and Haumea: Technique and Rationale. While you are over there you might also be interested in reading Cryovolcanism on Charon (Pluto's largest moon) which suggests that liquid water volcanoes could still erupt on Charon and another Palomar discovered world Quaoar.

Hot on Palomar

The National Weather Service is forecasting temperatures to be in the low 90s on Palomar Mountain through the weekend. Visitors to the mountains will not find much escape from the even higher temperatures that will bake the inland valleys.

Be sure to drink plenty of water for your travels.

Personally, I long for cooler weather and could even handle a light dusting of snow, like the one seen in this photo taken around 1960.

Asteroid Update

Once a month the Minor Planet Center updates their list of Minor Planet Discovery Sites. The total number of minor planets, which most people call asteroids, discovered at Palomar Observatory is split between those found through the Near-Earth Asteroid Tracking program and others found here on site. The total between the two, which was updated just last week, now stands at 21,609.

A Work of Art - II

Back in late May I posted about Mark Peiser's glass art based on Palomar's 200-inch mirror.

I just had some questions come my way concerning his work, so I thought I would post some photos of another piece. It's called Section 1, Detail 1 and was purchased by the Museum of Art and Design (MUDAC) in Lausanne, Switzerland.



I think that this piece really captures the flavor of our mirror's honeycombed underside. You can read more about Mark's project here from the Glass Quarterly blog and you can find Mark's website here.

Galileo, Neptune & Palomar

Neptune imaged in 2006 with the Hale Telescope & adaptive optics by Don Banfield of Cornell University

There are some stories in the news this week about the fact that Galileo spotted Neptune back in 1613. I didn't think that this was news. Former Palomar astronomer Charles Kowal made that discovery thirty years ago.

You can read his paper on this here and see that he and Stillman Drake published this in Nature back in 1980. Thanks to Palomar Skies commenter Anonymous for prodding me to post this for all.

Oscar Mayer & Palomar Observatory

Earlier this week I learned of the passing of Oscar G. Mayer, of meat-processing fame. I was a bit confused as I confess that I had already thought that Oscar G. Mayer had passed years ago. Why? Because at Palomar Observatory our 60-inch telescope resides in the Oscar G. Mayer Memorial Building. Here is the plaque that is inside the building:

As it turns out our building is named for Oscar G. Mayer, Sr. who passed in 1965. It was the younger Oscar G. Mayer who died this week.

Here is a short obituary from Google News:

Oscar Mayer

MADISON, Wis. (AP) — Oscar G. Mayer, retired chairman of the Wisconsin-based meat processing company that bears his name, died Monday. He was 95.

Mayer died of old age at Hospice Care in Fitchburg, said his wife, Geraldine.

He was the third Oscar Mayer in the family that founded Oscar Mayer Foods, which was once the largest private employer in Madison. His grandfather, Oscar F. Mayer, died in 1955 and his father, Oscar G. Mayer Sr., died in 1965.

Mayer retired as chairman of the board in 1977 at age 62 soon after the company recorded its first $1 billion year. The company was later sold to General Foods and is now a business unit of Kraft.

Our condolences go out to the Mayer family. The 60-inch telescope continues to generate impressive results. All these years later we still very much appreciate the Mayer Family's gift to astronomy. Here is the Oscar G. Mayer Memorial Building:


And the Hot Wheels version of the famed Oscar Mayer Weinermobile that resides on my desk:

There's No Place Like Dome

A week ago, I was waiting around at the observatory's visitor center to meet a reporter (who incidentally didn't show up) when I happened to meet a group of people with some amazing connections to the observatory.

I had no idea when I met them that they had ties to Corning Glass Works, James "Jimmie" Fassero (Author of The Photographic Giants of Palomar), 1930's Palomar plumber Thomas Young, and to the construction of our big dome. As the conversation went on I became more amazed. One of the ladies mentioned that she and her sister had even been here at the observatory and had their photo taken with the dome while it was under construction. Wow!

Thankfully, Betty and Ethel were kind enough to share that photo with me and have allowed me to share it with you.
That's Betty Dixon on the left and Ethel Dixon on the right. The photo was taken by their father Ralph E. Dixon, an Escondido citrus rancher.

For me this photo is unique of all the dome construction photos that I have ever seen at Palomar. It is not that I haven't seen people posing with the dome before. That's been going on since construction began in 1936.

To prove it, here's Edwin Hubble posed with the dome in 1936 1937:

Photo from the Journal of San Diego History

Note the Betty & Ethel had their photo taken with the dome before Edwin Hubble did. (Of course, Dr. Hubble did make sure the camera got his good side.)

I have also seen many unidentified people posing in front of the dome. Here is an example of a nice group photo from the past (possibly 1938):

The picture is one the photos of Thomas R. Young that were donated to the observatory in 2005. I love this photo, but I have no idea who any of the people are.

What makes the photo of Betty and Ethel so special for me is that they are the only people who I have actually met who were here to witness the event and have had their picture taken with the dome in the background. (For the sake of total disclosure, I have met Thomas Young's son, Hugh, and I do have a construction-era photo of him taken during construction from inside the dome.)

No one else is going to have the chance to have their photo taken in the same way the Betty & Ethel did, but the tradition of having your picture taken in front of the dome continues and has now spanned 73 years. On your next visit, be sure to have your picture taken here. Remember, we want everyone to have a chance to get into the shot. That's why we installed camera posts earlier this year.

In Case of Emergency . . .

What's that hanging on the wall of the 200-inch Hale Telescope's Data Room between the video monitor and the white board?

It is a Galileoscope!

Deer in the Ferns

Palomar Observatory is home to a great variety of wildlife. Like our visiting astronomers, many of the animals are nocturnal. Deer are very common, but usually only sighted during dusk and during the night.

Once in a while I seen them during the daytime, as I did earlier today:

Can you spot the deer in the ferns? There were actually two of them, but only one was visible when I took this photo. Here's a cropped version showing the one that was visible:

And the Winning Thesis is . . . . .

I just learned that the Astronomical Society of the Pacific is presenting their 2009 Robert J. Trumpler Award to Kevin Bundy. The Robert J. Trumpler Award is given each year to a recent recipient of the PhD degree in North America whose research is considered unusually important to astronomy.

From the ASP:

In his Caltech thesis, Dr. Bundy used observations with the Wide Field Infrared Camera (WIRC) at Palomar Observatory to quantify the galactic process called "downsizing," in which the sites of active star formation shift from high-mass galaxies early in the history of the universe to lower mass galaxies as time goes on. His study indicated that there is a galaxy mass limit beyond which some mechanism inhibits star formation so that massive galaxies become quiescent. Bundy's analysis of the evolution of the star formation rates and of galaxy morphology has been widely cited and is considered an important constraint on theories of early galaxy formation.

Congratulations Dr. Bundy! He is currently continuing his research at UC Berkeley.

Here is an image on edge-on spiral galaxy NGC 891 that Kevin helped obtain a few years ago using the Hale Telescope's Wide-field Infrared Camera (WIRC). It is a composite image from Palomar (Bundy) and the 10-meter W.M. Keck Observatory (Patrick Shopbell and Judy Cohen). Yellow colors in this composite correspond to the near-infrared image which was obtained at Palomar. The blue colors correspond to the visible light image which was obtained at Keck.

Ferns, Dome & Sky

Here's a nice shot of the Hale Telescope's dome taken last month. It was sent in to me by a recent visitor, Angela from Baja California, Mexico.


Gracias Angela!

Fred Givant: 1943 - 2009

I have the sad task of announcing that Fred Givant, one of the Palomar Observatory’s docents, passed away on Sunday June 28.

We only had the pleasure of knowing Fred for just a year and a half, but he certainly left his mark on the outreach program. Fred felt passionately about the observatory and especially the need to educate young people about science. He backed up that passion with frequent visits to the observatory to help with our public outreach program.

In spite of the fact that Fred had a fulltime job (working as a risk manager for a company building the next generation of GPS satellites) he was very committed to making the trek to Palomar Mountain to volunteer much of his limited free time. It has been a record-breaking year for tours at the observatory and Fred was a big part of that. He was volunteering here three of the four weekends in June and four of the five in May!

The staff and docents of the observatory will miss Fred’s enthusiasm and dedication.

A memorial service for Fred will be held on July 10 at the Miller-Jones Mortuary in Sun City, CA. Fred’s wife Carole has asked that instead of flowers donations be made to Palomar Observatory.

Anyone wishing to make a donation can send it to:

Palomar Observatory
Fred Givant Fund
P.O. Box 200
Palomar Mountain, CA 92060

100% of the donations to the fund will be used to help kids to learn about astronomy. Fred would have wanted it that way.

Here's a docent group photo from last year. Fred is second from the left.

Anniversary of Newton's Principia

Perhaps the most important book in science, Isaac Newton's Principia was published on this date (July 5) in 1687.

The folks over at Jodrell Bank have a nice video celebration of Isaac Newton and Principia in their latest Jodcast.

If you are looking for a good read on Sir Isaac Newton, you might try the book I am currently reading, Newton and the Counterfeiter: The Unknown Detective Career of the World's Greatest Scientist by Thomas Levenson.

To tie this all back to Palomar (after all that's what this blog is about) here is Palomar's 200-inch mirror with the crew of opticians who ground and polished the glass. In the center of the disc is a full-sized replica of the first reflecting telescope ever built, constructed by Sir Isaac Newton in 1671.

Galileoscopes: Delivered!

Check it out, our Order of Galileoscopes has arrived!


Hopefully I'll have a real review of them posted in the next week or so.

4th of July Fireworks in 1054 A.D.

Some people are going to experience some big Independence Day fireworks shows tonight. None of them will rival the one that the Chinese saw on July 4, 1054 A.D. They witnessed the explosive (supernova) death of a massive star. The "guest star" that they saw was so bright that it became visible in the daytime for 23 days and at night it cast shadows!

The remnant of this colossal event is now known as the Crab Nebula(also called as M1 and NGC 1952).

Hundreds of years after the event was seen observations by Mt. Wilson/Palomar astronomer Walter Baade helped to tie the nebula to the eyewitness reports from the Chinese astronomers.

In honor of the 955th anniversary of the supernova being seen on Earth I give you 2 photos of the Crab Nebula.

This first image is a vintage (possibly 1959) photo from the 200-inch Hale Telescope.

Contrasting the vintage shot is a modern image, again taken using the Hale Telescope.


The modern image looks pretty different, that mostly because it was taken in near infrared light. So the colors seen in the image are not at all what your eyes would see because your eyes can't see into the near infrared.

The Crab Nebula is located approximately 6,300 light years away. It is some 10 light years across and is expanding at about 1,800 km/sec.

At the heart of the nebula lies the Crab Nebula pulsar. The pulsar is neutron star that spins 30 times per second. It is heavier than our Sun but only about 20 kilometers (12.4 miles) across! That makes the diameter of the pulsar a little bigger than the length of Palomar Mountain, yet it weighs more than the Sun.

The pulsar is arrowed in the zoomed version below.

Palomar Skies on twitter (finally)

Palomar Skies is finally on twitter.

Three Cheers for the Red, White & Blue

It is nearly Independence Day, so (here in the U.S. anyway) it is time to show off patriotic colors.

To celebrate here's a vintage shot of the Trifid Nebula (M20) as shot from the 200-inch Hale Telescope:

The reddish portions are ionized light from an emission nebula and the blue is from reflection nebula (starlight scattering off of dust).

I am reasonably sure that this shot was from 1961. Imaging at the professional and amateur levels has leaped far beyond what could be done by anyone 40-50 years ago.