Thursday, June 30, 2005
Comets, Asteroids, And Brown Dwarfs, O My!
The 200 inch Big Eye is the signature scope at Mt. Palomar (click here for website) but there are other scopes at the observatory that contribute as much or more to science. They are just a lot smaller. For instance, there's the next largest scope, the 60 inch "Pig Eye." (The photo above is the scope's base.)
Besides rhyming with Big Eye, the 60 inch scope's nickname, Pig Eye, is an affectionate reminder of its origin. The scope was donated to the observatory in 1970 by the Oscar Mayer Company at a ceremony attended by the company's namesake. Who knew the company was named after an actual person? (Here's a full picture of the scope.)
Pig Eye's most notable achievement came in 1994 with the discovery of the first brown dwarf, Gliese 229B, located 19 light years from Sol in the Gliese 229 system. The brown dwarf is 20 to 50 times more massive than Jupiter, too big and hot to be a planet but too small and cool to be a star. (Click here for more info on these unusual heavenly bodies.)
Pig Eye is mostly used to observe planets within the Heliosphere and distant planetary nebulae. The 60 inch scope has only a 4 month waiting list for use as opposed to the 200 inch scope's 4 year wait. The small room (pictured at left) on the second floor of the dome is the control room.
It's not always used because Pig Eye can be operated remotely. It recently had a new operating system and camera installed so that astronomers at Cal Tech and elsewhere could use the scope without having to make the long trip to Mt Palomar.
Another scope at the observatory is the 48 inch Samuel Oschin. (The scope's dome is pictured at right.) The dome looks like any other dome at the observatory but the scope inside is very important to the safety of all humankind.
The Samuel Oschin is used in the Near Earth Asteroid Tracking project (NEAT, click here for website)
The NEAT project tracks the asteroids that circle the Earth near the Earth's orbit. There are 3440 know asteroids whose orbits are near to Earth's. In 1900 only 18 had been discovered. NEAT's goal is to find 90 percent of the near-Earth asteroids with diameters greater than 1 kilometer by 2008. An asteroid of that size could cause really serious problems for humans if it were to collide with the Earth. So every night the Samuel Oschin takes 200 pictures of the night sky with its 16 megapixel camera and computers compare the photographs against images of known fixed stars in the sky. The extra specks of light in the photographs are the asteroids. NEAT astronomers then track these asteroids to plot their orbits to determine whether any of them pose a risk of collision now or into the future.
Another scope on site is the 18 inch Schmidt. The Schmidt is the oldest scope at the observatory. It became operational in 1936. Its most notable achievement was the discovery of Shoemaker-Levy. In its history the scope discovered 50 comets but it is no longer used for scientific research. (The Schmidt's dome is pictured below.)
Come back tomorrow for more Open House photos.
Labels: Palomar Open House 2005
Tuesday, June 28, 2005
Light Pollution Or Civilization?
As at every astronomy event there was information about light pollution. Astronomers spend their lives trying to find places with clear skies and near total darkness. Mt. Palomar itself was chosen as an observatory earlier this century because the light pollution from Los Angeles was becoming too bright for good observation at Mt. Wilson.
Even Mt. Palomar is encountering light pollution. San Diego for years used low sodium lights to help keep the skies dark for astronomy at Mt. Palomar. Recently the city has gone away from those lights. As a night owl and a San Diego resident I have to say I hated the low sodium lights. A city illuminated at night with low sodium lights is an ugly city. There's hardly anything more beautiful than a modern city lit up at night.
This map was displayed at the Open House to show the area where light pollution affects astronomy at Mt. Palomar. (Click photo to enlarge.)
The light pollution zone encompasses a huge area of Southern California. It includes San Diego, a city of over 1 million people, and a county of over 2 million, and the southern part of Riverside County, perhaps the fastest growing region in California. There were some reasonable suggestions given about trying to limit the amount of light that spills up into the sky by hooding lights so the illumination is directed to the ground not the sky. (Click here for more information on limiting light pollution.) But ultimately Southern California, home to millions now and millions more in the future, can only do so much to reduce lighting in order to accomodate an observatory. Astronomy at Mt. Palomar is doomed.
There still remain large areas on Earth where the skies at night are dark. But the future of astronomy is in the sky, in Earth orbit, on the moon, or elsewhere. This famous NASA photograph of the Earth shows where the sky is lit up at night and where it is dark. (Click photo to enlarge.)
(Photo credit to C. Mayhew & R. Simmon (NASA/GSFC), NOAA/NGDC, DMSP.)
The photograph is a visible and striking illustration of where technological civilization exists and where it does not. It also reveals the irony of astronomy, perhaps the first science of civilized humanity. Today the best place to put an observatory is far away from civilization. In terms of light pollution, in fact, the ideal place for an observatory appears to be that patch of utter darkness in East Asia, just north of Seoul and just south of Manchuria: North Korea; about as far from civilization as a person can go in the modern world.
Photos Of The "Big Eye" At Mt. Palomar Observatory.
The large telescope's dome is the dominant feature on the 200 acre observatory site. The dome is 135 feet tall by 137 feet in diameter and weighs 1,000 tons. From a distance the dome is obviously a large structure. But it's a close-up view that drives home the dome's enormous size. The picture below shows just how big the dome is. Note the tiny people walking along the catwalk that encircles the dome.
Big Eye's enormous size is revealed inside the dome where the scope has made its home since 1948. The scope is so large that a small cage-enclosed control room is attached to the bottom it. The control room hangs about 8 feet or so above the floor. The picture below is a shot of the bottom of the scope and the cage hanging above the floor.
Most telescopes give the impression of fragility. Not this one. Big Eye's 200 inch mirror alone weighs 40 tons. Its huge size requires massive machinery to move it about inside the dome and position it for viewing. The impression is not of a delicate instrument at all. Instead the scope's steel framework and machinery creates an impression of massive strength. Almost like a very large cannon. This next picture was taken from the floor and shows part of the mechanism that controls the scope's movement.
This next picture was taken from an inside second-story catwalk and shows more of the machinery that holds the scope and moves it around.
This picture is once again taken in near darkness. It's also taken from the second story catwalk. It shows the scaffolding that holds the telescope nestled in the machinery. You can click on the image to increase its size. With luck this may make it easier to view.
Back on the floor for a shot of the astronomers in the cage preparing for the night's viewing. There's up to a four-year waiting list for telescope time on Big Eye. Bad weather or technical difficulties can ruin an observation run. There's no do-overs, either. If the run is ruined the astronomers have to get back on the waiting list and hope that next time the weather is clear. The weather was good on this day so nobody in the control cage appeared particularly nervous. They were spending a lot of time huddled around the computers, however.
Like any machine the 200 inch telescope at Palomar needs maintenance. The mirror has to be cleaned and re-aluminized every two years or so. (Click here for website showing that process.) Besides the telescope and its machinery, there were two structures used in the aluminizing process. The first picture shows the unit that holds the mirror when it is removed from the scope for cleaning.
This next picture shows the re-aluminizing unit. During re-aluminization the 17.5 ton unit is lifted by a crane to the top of the unit holding the mirror. Air is evacuated and tungsten coils with aluminum draped on them are heated, which vaporizes the aluminum and coats the mirror leaving it shiny and new. The mirror just happened to have been re-aluminized the week before the open house.
Finally, the picture below shows a small replica of the 200 inch telescope. The replica is controlled by an electric motor that visitors can operate to learn how the scope moves. Unfortunately, this is probably the best photograph of what the scope looks like that I was able to take.
That's it for today's photographs. Come back again for others, including the 60 inch scope, the Palomar Testbed Interferometer, and more.
Labels: Palomar Open House 2005
Friday, June 24, 2005
We Don't Need No Stinkin' Tax Dollars!
Somebody did not do their research for this one. In fact, NASA had nothing to do with the building of the MDRS, as it's called, and NASA doesn't maintain it either.
Sure, there are NASA scientists and employees who serve there as crew sometimes. On their vacations! But MDRS is not a NASA facility, and it never has been one.
Who built it, who maintains it, who crews it, and who pays for it?
The volunteers and members of the Mars Society with their dues and hard work, me among them, and there's nary a government bureaucrat for miles around and no tax dollars either. And that's the way we like it.
If you want to know more go to the Mars Society's website. (Click here.)
UPDATE: I've been told that some of the NASA employees who go to MDRS get paid to go there.
Thursday, June 23, 2005
Palomar Observatory Open House
This Saturday, June 25, 2005, I'll be attending the open house at Mt. Palomar Observatory in the mountains east of San Diego. Look for pictures and stories on this website next week. This photo is taken from the Palomar Observatory home page. For more information on the open house go to http://www.astro.caltech.edu/palomarnew/friends/openhouse.html.
Labels: Palomar Open House 2005
What Did Tolkien Know And When Did He Know It?
This is an image of the star Fomalhaut and its ring of dust particles taken by Hubble. (NASA, ESA, Kalas/Graham/UCB, Clampin/NASA/GSFC.) It is the first visible light image of Fomalhaut's ring of dust particles. It's strikingly beautiful. Fans of Lord of the Rings will recognize its similarity to the Eye of Sauron. Face on Mars types are bound to have a field day with this coincidence. Read more about the discovery at http://www.newscientistspace.com/article.ns?id=dn7564.
Wednesday, June 22, 2005
These Are The Voyages Of The White Knight.
Cosmos 1 Likely Crashed During Boost Phase
Here's the word from the planetary society.
Look for 24 hour coverage of the "Search for Cosmos 1" on cable news with interviews of the worried parents at the Planetary Society.
Sunday, June 19, 2005
Take A Sub-Orbital Tourism Survey
Thursday, June 16, 2005
Why Life Must Have Been On Mars Long Ago.
Peterson turned to his lifetime of studying geology here on Earth to Mars to make his case. Peterson took as his bedrock (it's a pun, I know, live with it) three assumptions that all terrestrial planets in the solar system formed at the same time, the same way, and from the same materials, through a long process of asteroid and comet collisions. The differences among the terrestrial planets today are due to their different masses and distances from the sun, which have affected their evolution over time.
All things being equal Mars should be like Earth. But Earth's mass has enabled it to hold on to most gases during its long life and given us our present atmosphere dominated by nitrogen and oxygen. The lighter mass of Mars on the other hand has caused it to lose most of its atmosphere except for the heavy gas carbon dioxide, and has left it with less than one percent oxygen. It also means that the pressure of the red planet's atmosphere today is less than one percent that of Earth's. That lower pressure, and the red planet's farther distance from the Sun, causes Mars to have an average temperature well below zero.
But the planet's red face means that some time in its distant past, Mars must have had oxygen levels as high as Earth's today, tropical temperatures, flowing water, and a thick atmosphere. According to Peterson, that red face also means that life probably existed on Mars when the Earth-like conditions existed there.
Red rock is hematite, which is made when basalt oxidizes, which requires moisture and oxygen. Basalt only turns red during oxidation in tropical temperatures. In colder temperatures, basalt oxidizes into a darker rust color. But what about red rock in St. George, Utah? That's nowhere near the tropics now but Peterson pointed out that during the Triassic period the area that eventually became St. George was below 20 degree north latitude in the tropics.
Mars has red rock on a global scale, which means that for a long time in its distant past, Mars was a tropical planet.
As Peterson put it, basalt on Earth oxidizes into hematite "reluctantly" despite a level of atmospheric oxygen at 21 percent. At some time in its past, up to 40 percent of Earth's atmosphere was oxygen. The less than one percent level of oxygen on Mars today is not sufficient to have oxidized the planet on a global scale. Thus, at one time in its past, Mars had to have oxygen levels similar to Earth's.
How does an atmosphere get oxygen? According to Peterson, oxygen is created two ways, either by photochemical dissociation, when sunlight reacts with water vapor to free the oxygen. The other source is life's process of photosynthesis. The interaction of sunlight and water vapor does not create the amounts of atmospheric oxygen needed to enable basalt to oxidize into hematite. Here on Earth, our atmosphere contains only one percent oxygen created by sunlight and water vapor. Twenty percent of our atmosphere is oxygen created by photosynthesis, mostly from bacterial life.
Thus, Peterson concludes, for Mars to have rusted red on a global scale it must have had a high percentage of oxygen in its atmosphere at one time. Since photochemical dissociation doesn't create enough atmospheric oxygen to turn basalt to hematite over an entire planet, photosynthesis, probably from bacterial life, must have filled the Martian atmosphere with the oxygen that eventually turned Mars into the rusted red rock it is today.
After the formal talk, Peterson speculated that the atmospheric methane on Mars could come from long-dead Martian life in oil shale. Oil shale is formed on Earth from deposits of silt and organic debris on lakebeds and sea bottoms. Heat and pressure change the deposits into a stable mixture of inorganic minerals and solidified organic sludge, known as oil shale. (Click here for Wikipedia article.)
If Peterson's correct that there's shale oil in them thar former lake bed craters on Mars, the US has just the right president in office today to lead the way. Operation Martian Freedom, anybody?
Friday, June 10, 2005
Terraforming Is Nothing To Sneeze At.
The story gives new relevance to W.C. Fields' remark that he wouldn't drink water because fish swim in it.
It's also a humbling lesson for would-be terraformers about the immense complexity involved in creating new ecosystems on other planets.
To cite one example, it's gonna take a lot more than melting the ice caps and planting some hardy vegetation to make a living planet out of Mars. If the theory that Mars started out warm and wet and wonderful is true then God was the first terraformer of Mars. Looking at the results today, it's hard to judge that he did a very good job of it. I wonder how much better a job we can do. I mean, who'd have thought there'd be a need in the life-cycle for giant floating snot balls?
Sunday, June 05, 2005
Better Dead And Red
These stories in Nature and New Scientist suggest that the methane could be produced by a mineral that we know is very common on Mars: olivine. (Click here and here for stories.)
This is probably a minority view but I, for one, would be very pleased if the methane turns out to come from olivine and not from life.
The possibility of life on Mars is very much a two-edged sword for human exploration. On the one hand, the discovery of Martian life is a very good reason to spend the money needed to go to Mars. Finding life on Mars would be the greatest scientific discovery ever with implications for all of society. On the other hand, the risk of "contaminating" the planet is often used as an excuse not to send humans at all. In addition, the fear of back-contamination of Earth by Martians microbes is very real.
If the long-term objective of going to Mars is to create another home for humanity, it's better if Mars were dead not alive.
A living Mars is a Mars with owners. Owners who will have no shortage of people here on Earth willing to speak on their behalf to protect them from a human invasion. A Mars with life is a Mars that will be reserved for the Martians alone or for a select group of scientists. A Mars with life is a Mars that is likely to be off limits to settlement.
A dead Mars is a Mars without owners. It's a new world open for the taking. And if the olivine theory is correct, it's also a world with lots of subsurface water. The cost of space travel eventually will become affordable for ordinary people. It'd be a tragedy if the planet were off-limits to human occupation when that day comes. This blog's motto is "one day all this will be ours" for a reason. The heliosphere is our home. We just haven't moved into all the rooms yet. So I'm rooting for the olivine.
Thursday, June 02, 2005
Leave The Driving To Us?
"A new cargo-only module could be employed to replace the lost shuttle missions, [new NASA head Mike] Griffin said. The Agency [NASA] is currently examining proposals from 26 companies who want to ship cargo to the space station."
This quote illustrates a crossroads for NASA. The first sentence seems to describe an alternative to using the shuttle to supply the space station but one that still relies on a government owned and flown spaceship. Cheaper than the shuttle but not necessarily the cheapest or best way to go. The second sentence in the quote holds more promise for developing space. What that sentence means is there are a host of companies who are willing to tell NASA to "leave the driving to us" if NASA will pay them. This is evidence that a private space industry is poised to fly. It's also evidence that a lucrative market in the near term for that industry is likely to rely on the government as a customer.
The GAO has issued a short report (click here) criticizing NASA for failing to examine all alternatives to the shuttle for supplying the ISS. That report touts commercial launch options while also acknowledging there is a several year lead time for getting off the ground.
Still the exploration of space is a long-term project. If one compares how long it took humans to spread from Africa and cover the Earth to how long we've been in space, it's clear we are in the infancy of our migration off our home planet. NASA could bring down future costs enormously for doing the ordinary things in space in Low Earth Orbit if it would purchase services for those things. Transporting cargo to LEO should be done using the cheapest possible method of transportation. The competition inherent in the private sector is an effective way to find that cheaper road to space.
A speaker at this year's Space Access Conference in Phoenix cited the development of the North Slope in Alaska as an example. That development required transporting large amounts of material and smaller numbers of people to a distant and inhospitable location. Safety concerns and the profit motive meant that people were sent using more expensive transportation but supplies were sent using the cheapest transportation they could find. There is no reason why the same principle should not apply to the development of space.
Let's hope that under Mike Griffin and the Space Vision Thing NASA finally begins to rely on one of this country's guiding principles, a belief in free markets, to get us off the ground and into the cosmos.
Wednesday, June 01, 2005
Reader Comments On NASA's Slow Walk To Mars
This is a point that was made several times at the Space Access Society Conference in Phoenix this year. Cost-plus contracting puts creative people to work figuring out ways to increase the expense of not making things whereas operating under a fixed-price forces creative people to actually make things and do it cheaper. Mealing seems to be on to something with his comment.
Like Mealing, I too wonder what the business plan would be for a private mission to Mars. Space exploration advocates worry about the prospect of a government mission to Mars that is nothing more than a flags and footprints mission in which astronauts go to Mars, plant some flags, leave, and never come back. Sort of like Apollo.
I wonder if private missions to Mars, or even the Moon, could end up being nothing more than "boots and billboards" missions (to coin a phrase) without any plans for follow-on missions either. Perhaps it's my own limited imagination but I find it hard to envision a realistic business plan for profitable private space missions to the Moon or Mars in the near future. Anybody have a suggestion or two they'd like to share?
Science fiction author Brian Enke looks at the cost side of the equation rather than the benefit side and says he'll list some ways to reduce the cost of missions to Mars on his own website (ShadowsOfMedusa.com). His comment about the expense associated with current technology reminds me of a point I've heard made by Dr. Michael Caplinger, a scientist at Malin Space Science Systems (MSSS.com) here in San Diego. Caplinger makes the point that given current technology we won't be sending humans to Mars unless we have a really good reason to justify the expense of sending people there, or we'll send humans when we have a propulsion method cheap enough to operate that we can go there for no reason at all. I'm hoping for something somewhere in the middle and sooner rather than later.