by Paul Gilster | Dec 24, 2008 | Culture and Society |
By Larry Klaes
Years after Apollo, I ran into Frank Borman in a pilot’s lounge at a southern airport. I was waiting for a student who wanted to use the lowering weather to practice instrument approaches. Borman was just passing through. Then CEO of Eastern Airlines, he was accompanied by lawyers and was busy signing papers. I wanted to tell Apollo 8’s commander what that mission had meant to me, but I found myself completely tongue-tied. How to even begin to express what that first human presence around the Moon meant to all of us, and how to say it in ways that hadn’t been said a thousand times before? Larry Klaes is, fortunately, at no such loss of words as he describes what many still see as the most daring mission ever flown, and the stunning images and audio it sent back on that Christmas Eve forty years ago.
On Christmas Eve in 1968, three men took turns reading aloud from the Book of Genesis in the Bible. Such an event might not be terribly unusual then or now, considering the time of year in which it took place.
But the three people in question were no ordinary men, and they were speaking in no ordinary place. They were astronauts, and they were reading the ancient Christian story of the creation of heaven and Earth while in the heavens themselves aboard a silvery, conical spacecraft, with a view no other human being had ever witnessed in person before – from the vicinity of the Moon a quarter of a million miles away.
Image: The flight crew of the Apollo 8 mission, Commander Frank Borman, Command Module Pilot James A. Lovell, Jr., and Lunar Module Pilot William A. Anders, hold a replica of the Collier Trophy awarded for their historic first flight to the Moon. Credit on this and photos below: NASA.
Forty years ago this month, American astronauts Frank Borman, Jim Lovell, and William Anders were launched aboard a spacecraft named after an ancient god of many talents to become the first humans to ever leave low Earth orbit, where all previous manned space missions had stayed since the first one just seven years earlier, and venture to our planet’s only natural satellite.
It would be nice to say the mission of Apollo 8 was done purely in the spirit of adventure to gain new knowledge about the Universe. Certainly there was that element to this space expedition. However, Apollo was also created to best a rival nation with its own space program that had beaten the United States with numerous firsts into the void.
America’s chief opponent of the Cold War, the Soviet Union, had, in just over one decade, placed into Earth orbit the first satellite, living creature (a dog), man, woman, and conducted the first spacewalk. Further out, the Soviets also claimed the first robot spacecraft to land on the Moon and Venus. The communist nation had even sent a collection of plants and animals around the Moon aboard a spacecraft named Zond 5 just months before the launch of Apollo 8, returning them safely to Earth.
Image: A launch like no other, one that suddenly expanded our thinking beyond Earth orbit with a single, daring thrust.
The Zond vessel was a modified version of the Soviets’ then-new Soyuz manned spacecraft. It was evident to Western analysts that the Soviets were getting ready to send several cosmonauts to the Moon with their Zond, certainly to circle the distant globe and perhaps even to land upon it. With the prospect of the foreign superpower outdoing the Americans yet again with another and quite major space first, Apollo 8’s original mission to fly in a high Earth orbit was dramatically changed.
The new goal of Apollo 8 was to have three astronauts travel approximately 240,000 miles across space to orbit the Moon at least ten times before returning to our planet. Apollo had flown only once before with a human crew, orbiting just a few hundreds miles above our blue and white globe. The Lunar Module, the component of Apollo that would take two astronauts all the way to the lunar surface, was not ready yet to accompany the Command/Service Module (CSM) portions of the mission, so the astronauts would be traveling to the Moon without what would later become known as a “lifeboat” for the spacemen. Ironically, Command Module Pilot Lovell would have his life saved by a Lunar Module just two years later when a CSM oxygen tank exploded during the Apollo 13 mission, aborting the planned lunar landing and forcing the crew to use their Lunar Module to help get them home alive.
Image: Apollo 8 was all about changes in perspective. Suddenly we were seeing the Earth whole. Look closely and you can see nearly the entire Western Hemisphere, from the mouth of the St. Lawrence River, including nearby Newfoundland, to Tierra del Fuego at the southern tip of South America. Central America is clearly outlined. Nearly all of South America is covered by clouds except the high Andes mountain chain along the west coast.
Apollo 8 lifted off from Cape Kennedy in Florida on December 21, 1968 with the help from one of the most powerful rockets ever built, the Saturn 5. Three hundred and sixty-three feet tall, the Saturn rocket weighed over six million pounds and could loft 100,000 pounds to the Moon. No humans had ever ridden on such an incredible booster before, but thankfully the Saturn 5 worked as planned, sending Borman, Lovell, and Anders on a three day journey across space to Earth’s nearest neighbor.
When Apollo 8 arrived at the Moon on Christmas Eve, the astronauts began taking hundreds of images of the lunar surface, which Lovell described as “essentially gray, no color, looks like plaster of Paris or sort of a grayish beach sand.” Fascinating as it was to be orbiting an alien world closer than anyone had done before, the Moon was clearly a place where unprotected life from Earth would have no chance of surviving.
It was during this day of historical accomplishment and the reading of Genesis from the Bible that the crew of Apollo 8 made another important contribution to the uplifting of their species. The astronauts became the first people to witness the rising of their home planet above the lunar surface. The seemingly small orb with its bright blue oceans and white clouds stood out in stark contrast with the grayish Moon and the utter blackness of space all around. The photographs taken by the astronauts of that incredible sight did much to bring home to the people living on Earth of the finite nature of their world that they all shared. These images of our planet from deep space taken by Apollo 8 and subsequent lunar missions have often been credited with being the catalyst for the modern environmental movement.
Image: One of humanity’s most famous images, this one caught a contrast that highlighted what it means to be a living world.
“We came all this way to explore the Moon, and the most important thing is that we discovered the Earth,” remarked Anders on the images he took during the mission.
Apollo 8 returned to that “meadow in the sky,” as Earth would later be called on December 27, splashing down in the Pacific Ocean. The space capsule is now on display at the Chicago Museum of Science and Industry.
Though humans stopped going to the Moon in person after Apollo 17 in late 1972, there are plans for new manned expeditions in the coming decades, including permanently manned bases on the lunar surface. Those future explorers will have to thank the bold mission that paved the way for them four decades ago.
by Paul Gilster | Dec 23, 2008 | Exoplanetary Science |
A new camera called OPTIC (Orthogonal Parallel Transfer Imaging Camera), built at the University of Hawaii, has clarified our view of the distant world known as WASP-10b. Transits are helpful because they allow us to measure the size of the observed planets, and in this case, WASP-10b turns out to be not one of the most bloated exoplanets yet found, as once thought, but one of the densest. Orbiting some 300 light years from Earth, the planet’s diameter is now known to be only six percent larger than Jupiter’s, although it is three times more massive, with a corresponding density three times that of Jupiter.
OPTIC is mounted on the University of Hawaii’s 2.2-meter telescope on Mauna Kea. If you compare what it can do with its highly sensitive and stable detector to the best results from charge-coupled devices (CCDs), you find a photometric precision two to three times higher. According to this news release from the university’s Institute for Astronomy, that’s comparable to the most recent results from the Hubble Space Telescope for stars of the same brightness. Says team member Joshua Winn (MIT), “This new detector design is really going to change the way we study planets. It’s the killer app for planet transits.”
Image: When the planet WASP-10b crosses the disk of its star, WASP-10, the brightness of the star decreases, allowing scientists to measure the precise size of the planet. Credit: UH/IfA.
WASP-10 is a K-class star about 75 percent as massive as the Sun, one of only nine known low-mass planet host stars within 200 parsecs. More on the WASP-10b findings in Johnson et al., “A Smaller Radius for the Transiting Exoplanet WASP-10b,” available online.
by Paul Gilster | Dec 22, 2008 | Exotic Physics |
“It’s no longer completely crazy to ask what happened before the Big Bang,” says Caltech’s Marc Kamionkowski. A good thing, too, for this is an absorbing subject, one I’ve been interested in ever since reading Poul Anderson’s 1971 novel Tau Zero, in which the crew of the runaway starship Leonora Christine punches through into another universe. That novel assumed a cyclic universe, a collapse and a rebound, naturally making one ask whether a universe hadn’t existed before our own. If so, could we learn anything about it?
I would always have assumed the answer is no, but Kamionkowski’s work, and that of collaborators Adrienne Erickcek and Sean Carroll, at least opens the possibility that we might see an ‘imprint’ of that earlier universe in data we can collect today. The work grows out of measurements of the cosmic microwave background (CMB), as examined by the Wilkinson Microwave Anisotropy Probe. Temperature differences in the CMB can be used to study the theory of inflation, the idea that the universe went through a dramatic expansion immediately after the Big Bang, which would explain why it appears identical in all directions.
The problem is that the CMB isn’t as uniform as once thought. The Big Bang’s afterglow is more mottled in one half of the sky than the other. Exploring an energy field called the curvaton, which had been proposed to explain CMB fluctuations, Kamionkowski’s team tweaked the field so that its effects would more adequately explain the temperature variations. This theoretical tweak is, fortunately, subject to testing by the Planck satellite, which will launch in 2009. Says Erickcek:
“Inflation is a description of how the universe expanded. Its predictions have been verified, but what drove it and how long did it last? This is a way to look at what happened during inflation, which has a lot of blanks waiting to be filled in.”
Looking at the inflation era is itself extraordinary, but there is also the possibility that the perturbation the scientists introduced into the inflation picture is an imprint from whatever came before inflation. This is heady stuff, but it’s clear that Kamionkowski isn’t alone in thinking that we can perhaps glimpse some of these early mechanisms.
For a new paper by Jean-Luc Lehners and Paul Steinhardt (both at Princeton) looks first at cyclic universe models in which the universe undergoes periods of expansion and contraction, with a big crunch followed by a big bang marking the transition between the two, and then goes on to posit a ‘phoenix universe’ in which a tiny part of the universe survives the cataclysmic cycling but manages to become the basis for everything in the next universe. Steinhardt has been a major player in so-called ‘ekpyrotic universe’ models (a term meaning ‘out of the fire’), which offer alternatives to standard inflation.
Intriguingly, Lehners and Steinhardt see a role for dark energy in managing the survival of at least some of the earlier universe. This is dense and challenging reading, but the paper is well worth your time in its examination of this transformative process. A snippet:
…without adding some mechanism to force the universe to begin very close to the classical track, an overwhelming fraction of the universe fails to make it all the down the classical trajectory simply due to quantum ?uctuations. This fraction is transformed into highly inhomogeneous remnants and black holes that do not cycle or grow in the post-big bang phase. However, …something curious happens if the dark energy expansion phase preceding the ekpyrotic contraction phase lasts at least 600 billion years. Then, a sufficiently large patch of space makes it all the way down the classical trajectory and through the big bang such that, fourteen billion years later, it comprises the overwhelming majority of space. This surviving volume, which grows in absolute size from cycle to cycle, consists of a smooth, ?at, expanding space with nearly scale-invariant curvature perturbations, in accordance with what is observed today. As with the mythical phoenix, a new habitable universe grows from the ashes of the old.
A third way of poking into the early universe is Abhay Ashtekar’s work on a recycled universe that can be explained through loop quantum cosmology (LQC), a universe that works its way through an eternal series of expansions and contractions. New Scientist wrote this up in a recent article, examining the notion that space itself comes in the form of indivisible quanta 10-35 square meters in size. Martin Bojowald, working with Ashtekar at Penn State, used loop quantum gravity to create a model of the universe that has been the subject of much modification ever since. A singularity-free universe results, one in which universal collapse is reversed and the infinitely dense singularity disappears:
If LQC turns out to be right, our universe emerged from a pre-existing universe that had been expanding before contracting due to gravity. As all the matter squeezed into a microscopic volume, this universe approached the so-called Planck density, 5.1 × 1096 kilograms per cubic metre. At this stage, it stopped contracting and rebounded, giving us our universe.
The Planck density itself cannot be reached, as the New Scientist story goes on to explain:
According to Bojowald, that is because an extraordinary repulsive force develops in the fabric of space-time at densities equivalent to compressing a trillion solar masses down to the size of a proton. At this point, the quanta of space-time cannot be squeezed any further. The compressed space-time reacts by exerting an outward force strong enough to repulse gravity. This momentary act of repulsion causes the universe to rebound. From then on, the universe keeps expanding because of the inertia of the big bounce. Nothing can slow it down – except gravity.
How far we have to go in all this, but what fascination in the attempt! The mind sometimes boggles, but Anil Ananthaswamy’s article in New Scientist is a major help at untangling what Ashtekar is doing. Caltech offers a helpful news release on Kamionkowski’s work on asymmetry in the early universe; the paper itself (abstract here) is Kamionkowski et al., “A hemispherical power asymmetry from inflation,” Physical Review D Vol. 78, Issue 12 (16 December 2008). Lehners’ and Steinhardt’s paper is “Dark Energy and the Return of the Phoenix Universe,” available online.
by Paul Gilster | Dec 20, 2008 | Exoplanetary Science |
The Kepler mission launches March 5, a date to circle on your calendar. Kepler may become the first instrument to detect an Earth-size planet in the habitable zone of another star, using the transit method to examine 100,000 stars in its 3.5 year mission. The 0.95-meter diameter telescope is now at Ball Aerospace & Technologies (Boulder, CO), having passed the necessary environmental tests that demonstrate its space-worthiness. And word has just come that it has also passed the necessary ‘pre-ship review’ for transit to Florida in January.
Image: An artist’s rendering of what our galaxy might look like as viewed from outside. Our sun is about 25,000 light years from galactic center. The cone illustrates the neighborhood of our galaxy that the Kepler Mission will search to find habitable planets. Credit: Jon Lomberg.
The image above, the work of the fine space artist Jon Lomberg, gives an idea of where Kepler will be looking. As always, Lomberg (creator of the gorgeous Galaxy Garden in Hawaii) manages to put things in perspective. The 100,000 stars Kepler will examine seem a vast number, but note the size of the cone covered by these observations when played out against the galactic disk. Note, too, the relatively spare star fields out in our part of the galaxy, with the tightly packed core and its teeming stellar billions not in Kepler’s view.
I wish I could catch a glimpse of the container housing Kepler somewhere along its route to Florida. When I was researching my Centauri Dreams book, I was out at the Jet Propulsion Laboratory just before Spirit and Opportunity were shipped off for launch. I’ll never forget looking at the rovers and thinking that the next time I saw them, it would be through cameras mounted on each, capturing their shadows and tire tracks in the Martian terrain. Riding a Delta II rocket into space in a mere seventy-five days, Kepler promises just as stirring an outcome, one that should give us insight into how common terrestrial worlds really are.
by Paul Gilster | Dec 19, 2008 | Deep Sky Astronomy & Telescopes |
Give a young star two or three million years and planets are likely to emerge from the dust and gas surrounding it. But note the wild card shown in the image below, the danger of proximity to more massive stars. In the image, several stars not so different from our Sun at that stage of its evolution are shown with streams of material flowing away from them. We’re seeing their outer disk material blown away by nearby class O stars, while inner materials might still survive to form rocky, terrestrial worlds close to the parent star.
Image: This image from NASA’s Spitzer Space Telescope shows the nasty effects of living near a group of massive stars: radiation and winds from the massive stars (white spot in center) are blasting planet-making material away from stars like our Sun. The planetary material can be seen as comet-like tails behind three stars near the center of the picture. The tails are pointing away from the massive stellar furnaces that are blowing them outward. Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA.
This is a star forming region known as W5, 6500 light years from us in the constellation Cassiopeia, as seen in a composite of infrared data from the Spitzer Space Telescope. The massive stars involved are each about twenty times as massive as the Sun; the stars they are swamping with radiation and solar wind are about one light year away. And in astronomical terms, we’re looking at a short-lived phenomenon. JPL’s Xavier Koenig, lead author of a recent paper on this work, says these much abused disks will be gone in a million years.
It’s interesting to speculate on our Sun’s own origins given images like these. Surely it was born into a massive star-forming cloud which, over the eons, was dispersed as the stars it spawned moved away from each other. These are disruptive environments that eventually put the brakes on further star formation, but not before producing multiple stellar generations, as shown in the second infrared image of W5 from Spitzer below. Koenig and team have been studying W5 extensively with regard to this ‘triggering’ phenomenon.
Image: Generations of stars can be seen in this new infrared portrait from NASA’s Spitzer Space Telescope. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Younger stars line the rims of the cavities, and some can be seen as pink dots at the tips of the elephant-trunk-like pillars. The white knotty areas are where the youngest stars are forming. Red shows heated dust that pervades the region’s cavities, while green highlights dense clouds. Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA.
The paper on disk disruption is Koenig et al., “Dusty Cometary Globules in W5,” accepted for publication in Astrophysical Journal Letters (abstract). An earlier paper on ‘triggered’ star formation through the effects of massive stars is “Clustered and Triggered Star Formation in W5: Observations with Spitzer,” Astrophysical Journal Letters Volume 688, Number 2 (December 1, 2008), pp. 1142-1158. Available online.
