Apollo 8 Astronaut Bill Anders Reflects on Earthrise Picture

Earthrise Apollo 8. Image Credit: Bill Anders, NASA

In December of 1968, the Apollo 8 capsule had successfully gone into orbit around the moon and the crew was busy taking pictures of the lunar surface. On the third orbit, as the Apollo spacecraft was coming around from behind the moon, commander Frank Borman lookup up and called out, “Wow! Look at that!” The Earth was “rising” over the stark lunar horizon. Borman had a camera with black and white film, and he actually took the first picture of Earth rising over the moon. But Bill Anders had a color camera with a long lens, and he took the color photo that’s become an icon, known simply as “Earthrise.”

On Earth Day, Bill Anders reflected on the famous picture that’s become one of the most frequently used images ever.

Anders said even though it wasn’t in the original flight plan to take pictures of Earth, it didn’t take much time for him to realize how striking this view of the Earth was, and quickly snapped the celebrated image.

“I instantly thought it was ironic; we had come all this way to study the moon, and yet it was this view of the Earth that was one of the most important events for Apollo 8,” said Anders in an interview on NASA TV.

“There are basically two messages that came to me,” Anders said of the picture. “One of them is that the planet is quite fragile. It reminded me of a Christmas tree ornament. But the other message to me, and I don’t think this one has really sunk in yet, is that the Earth is really small. We’re not the center of the universe; we’re way out in left field on a tiny dust mote, but it is our home and we need to take care of it.”

Anders said it didn’t take long after the crew had returned home for this photograph to become iconic for the environmental movement.

“Back in the 60’s it gave us a sense that the world was a place we all shared together,” Anders said. “We couldn’t see any boundaries from space.”

In addition to the important pictures of Earth, the Apollo 8 crew also photographed many smaller lunar features, that were previously undiscovered. Those features are located principally on the farside of the Moon in areas that had been photographed only at much greater distances by early robotic spacecraft. The Apollo 8 mission yielded more than 150 photographs of the Earth and more than 700 photographs of the Moon.

Original News Source: NASA TV

It’s That Time of the Month for the Moon

Moon in Earths Magnetic tail. Image Credit: Science @ NASA

It happens every month and specifically every time the moon is full. According to scientists, for about three days on both sides of a full moon, the lunar surface could transform from a tranquil, inert landscape to an electrically charged, potentially dangerous environment. During this time, the moon ploughs through Earth’s magnetic “tail” — an extension of Earth’s magnetic field. Out in space, the solar wind stretches out the magnetic bubble that surrounds our planet, creating a long “magnetotail” in the downwind direction. When the moon comes in contact with this field, it could cause lunar dust storms and discharges of static electricity. Future lunar explorers might possibly have to take extra precautions during that time of the month.

“Earth’s magnetotail extends well beyond the orbit of the Moon and, once a month, the Moon orbits through it,” said scientist Tim Stubbs from the Goddard Space Flight Center. “This can have consequences ranging from lunar ‘dust storms’ to electrostatic discharges.”

When the moon crosses this magnetotail, it comes in contact with a gigantic “plasma sheet” of hot charged particles trapped in the tail. The lightest and most mobile of these particles, electrons, pepper the Moon’s surface and give the Moon a negative charge.

Scientists say that on the Moon’s dayside this effect is neutralized somewhat by sunlight. The ultraviolet photons knock electrons back off the surface, keeping the build-up of charge at relatively low levels. But on the nightside of the Moon, where it’s cold and dark, electrons accumulate and voltages can climb to hundreds or thousands of volts.

Stubbs said that astronauts walking across the dusty charged-up lunar terrain may find themselves crackling with electricity like “a sock pulled out of a hot dryer.” Touching another astronaut, a doorknob, a piece of sensitive electronics—any of these simple actions could produce an unwelcome zap. “Proper grounding is strongly recommended,” Stubbs said.

Moon dust could become charged enough to actually lift from the surface. There’s evidence from the Surveyor 7 lunar lander that when sufficiently charged-up, lunar dust particles could actually float above the lunar surface. This dust could cause problems as it clings to spacesuits, clogs machinery, scratches helmet faceplates (moondust is very abrasive) and generally make life difficult for astronauts.

Much of this is pure speculation, however, Stubbs said, as no one has been on the moon during this time. “Apollo astronauts never landed on a full Moon and they never experienced the magnetotail.”

The best direct evidence of this event comes from NASA’s Lunar Prospector spacecraft, which orbited the Moon in 1998-99 and monitored many magnetotail crossings. During some crossings, the spacecraft sensed big changes in the lunar nightside voltage, jumping from -200 V to -1000 V, according to Jasper Halekas of UC Berkeley who has been studying the data.

Scientists also say this phenomenon would be worse during a solar storm.

More research will have to be done regarding this monthly cycle and how it might affect those living on the moon in the future.

Original News Source: Science @ NASA

The Debate Continues: Water or Land Landings for Orion

The development of Constellation is continuing, the U.S. program that will replace the shuttle and send astronauts back to the moon. Two unresolved issues have stood out specifically for the Orion crew vehicle: Orion is currently too heavy for the Ares vehicle to launch it from Earth, and the decision on whether Orion will land in water or on land has yet to be determined. Originally, land landings were the preferred choice, but last December, it appeared program managers were leaning towards returning to the water landings seen during the Apollo era. But recently NASASpaceflight.com reported on a possible solution for the weight problem that could potentially provide an improved capacity for landing on land as well.

Needing to save mass on Orion to make it lighter prompted engineers to re-design the airbags that would be part of the vehicle to as a “contingency Land Landing requirement,” according to the article on NASASpaceflight.com. The new airbag system uses a smaller number of airbags than the original concept. As a result, the new airbag system is lighter. Engineers believe the new “back-up” system could possibly work well enough to be the primary system and allow land landings to be what NASA calls “nominal,” or the primary, preferred means of landing.

The upside of landing on land is that there’s a better chance of being able to reuse the command module, as opposed to landing in the ocean. Additionally, there’s some who believe returning to water landings is a step backwards for human spaceflight.

The airbags in the proposed new design are deployed out of the lower conical backshell on the Orion vehicle. Just before landing , the airbags would inflate and wrap around the low hanging corner of the heat shield. Upon landing, the airbags are vented at a specific pressure so that they collapse at a controlled rate to ease off the energy load of the spacecraft.

Although this new system has yet to undergo detailed analysis, initial results are viewed as promising on the ability to reduce crew loads to an acceptable level.

NASASpaceflight.com reported that another notable challenge for the Orion vehicle relates to maintaining the spacecraft’s orientation to minimize chance of tumbling during descent. A Reaction Control System (RCS) is being developed, which supposedly is preferred by engineers over retro rockets.

NASA did report last week the successful first full-scale rocket motor test for Orion’s launch abort system. This system would separate the crew module from Ares if an emergency occurred during launch.

Original News Source: NASASpaceflight.com

The Odds of Intelligent Life in the Universe

Tropical Saturn. Image credit: Columbia University

When it comes to contemplating the state of our universe, the question likely most prevalent on people’s minds is, “Is anyone else like us out there?” The famous Drake Equation, even when worked out with fairly moderate numbers, seemingly suggests the probable amount of intelligent, communicating civilizations could be quite numerous. But a new paper published by a scientist from the University of East Anglia suggests the odds of finding new life on other Earth-like planets are low, given the time it has taken for beings such as humans to evolve combined with the remaining life span of Earth.

Professor Andrew Watson says that structurally complex and intelligent life evolved relatively late on Earth, and in looking at the probability of the difficult and critical evolutionary steps that occurred in relation to the life span of Earth, provides an improved mathematical model for the evolution of intelligent life.

According to Watson, a limit to evolution is the habitability of Earth, and any other Earth-like planets, which will end as the sun brightens. Solar models predict that the brightness of the sun is increasing, while temperature models suggest that because of this the future life span of Earth will be “only” about another billion years, a short time compared to the four billion years since life first appeared on the planet.

“The Earth’s biosphere is now in its old age and this has implications for our understanding of the likelihood of complex life and intelligence arising on any given planet,” said Watson.

Some scientists believe the extreme age of the universe and its vast number of stars suggests that if the Earth is typical, extraterrestrial life should be common. Watson, however, believes the age of the universe is working against the odds.

“At present, Earth is the only example we have of a planet with life,” he said. “If we learned the planet would be habitable for a set period and that we had evolved early in this period, then even with a sample of one, we’d suspect that evolution from simple to complex and intelligent life was quite likely to occur. By contrast, we now believe that we evolved late in the habitable period, and this suggests that our evolution is rather unlikely. In fact, the timing of events is consistent with it being very rare indeed.”

Watson, it seems, takes the Fermi Paradox to heart in his considerations. The Fermi Paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.

Watson suggests the number of evolutionary steps needed to create intelligent life, in the case of humans, is four. These include the emergence of single-celled bacteria, complex cells, specialized cells allowing complex life forms, and intelligent life with an established language.

“Complex life is separated from the simplest life forms by several very unlikely steps and therefore will be much less common. Intelligence is one step further, so it is much less common still,” said Prof Watson.

Watson’s model suggests an upper limit for the probability of each step occurring is 10 per cent or less, so the chances of intelligent life emerging is low — less than 0.01 per cent over four billion years.

Each step is independent of the other and can only take place after the previous steps in the sequence have occurred. They tend to be evenly spaced through Earth’s history and this is consistent with some of the major transitions identified in the evolution of life on Earth.

Here is more about the Drake Equation.

Here is more information about the Fermi Paradox.

Original News Source: University of East Anglia Press Release

Stellar Birth in the Galactic Wilderness

This just in from the pretty pictures department at NASA. NASA’s Galaxy Evolution Explorer (GALEX) shows young stars sprouting up in a relatively desolate region of space more than 100,000 light-years from the galaxy’s bustling center. This striking image is a composite of ultraviolet data from GALEX and radio data from the Very Large Array in New Mexico, and shows the Southern Pinwheel galaxy, also known simply as M83. “It is absolutely stunning that we find such an enormous number of young stars up to 140,000 light-years away from the center of M83,” said Frank Bigiel, lead investigator of the new Galaxy Evolution Explorer observations. For comparison, the diameter of M83 is only 40,000 light-years across.

M83 is located 15 million light-years away in the southern constellation Hydra. The ultraviolet image was taken by NASA’s Galaxy Evolution Explorer between March 15 and May 20, 2007.

In this view, the main spiral, or stellar, disk of M83 looks like a pink and blue pinwheel, while its outer arms appear to flap away from the galaxy like giant red streamers. It is within these so-called extended galaxy arms that, to the surprise of astronomers, new stars are forming.

This side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy’s long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms.

Astronomers speculate that the young stars seen far out in M83 could have formed under conditions resembling those of the early universe, a time when space was not yet enriched with dust and heavier elements.

“Even with today’s most powerful telescopes, it is extremely difficult to study the first generation of star formation. These new observations provide a unique opportunity to study how early generation stars might have formed,” said co-investigator Mark Seibert of the Observatories of the Carnegie Institution of Washington in Pasadena.

Original News Source: NASA GALEX press release

Mars Express: Looking Beneath Mars’ Surface

MARSIS
MARSIS fully deployed orbiting Mars. Image credit: ESA

To truly know and understand another world, planetary scientists need to look beneath the surface of that planet. This has been done on a small scale by looking inside impact craters, a la Opportunity and Spirit on Mars. But that only provides information for one area on a big planet. To get the global picture of the subsurface, a radar sounder instrument was developed for ESA’s Mars Express spacecraft. The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) experiment has now been successfully used for the first time to look beneath Mars’ south polar ice cap, opening up the third dimension for planetary exploration. “We have demonstrated that the polar caps at Mars are mostly water ice, and produced an inventory so now we know exactly how much water there is,” says Roberto Orosei, MARSIS Deputy Principal Investigator.

The data from MARSIS’ probe of the ice cap is still being analyzed, but scientists say they expect some surprising results to be revealed.

MARSIS is built to map the distribution of liquid and solid water in the upper portions of the Martian crust, and can investigate Mars’ subsurface up to a depth of 5 km. If reservoirs of water are detected, it will help us understand the hydrological, geological, climatic and possibly biological evolution of Mars. “At the south pole of Mars, we are seeing through ice 3.7 km thick. A small calculation shows that we could see through ice down to 20 km or more thick at Mars,” says Ali Safaeinili, MARSIS co-investigator.

No one had ever used a radar sounder from orbit on another planet before. So the team was uncertain it would work as planned. The subsurface of the planet might have been too opaque to the radar waves or the upper levels of Mars’ atmosphere (ionosphere) might have distorted the signal too much to be useful.

But, the instrument worked perfectly.

Every time a radar wave crosses a boundary between different substances, it generates an echo that the orbiter detects.

See ESA’s 3-D simulation of the radar instrument.

While MARSIS is still collecting data, a follow-up instrument is already operating at Mars. The Shallow Subsurface Radar (SHARAD) on NASA’s Mars Reconnaissance Orbiter works at higher frequencies than MARSIS and can see more details in the signals it receives from the underground layers, but it can’t penetrate the surface quite as far.

The technique’s success is prompting scientists to think of all the other places in the Solar System where they would like to use radar sounders. One obvious target is Jupiter’s icy moon, Europa. There, a radar sounder could probe the moon’s icy crust to help understand the puzzling features we see on the surface. It may even see the interface at the bottom of the ice where an ocean is expected to begin.

Asteroids and comets could be thoroughly scanned by a radar sounder, producing three-dimensional maps of their interior– perhaps exactly the data we will need if, one day, we have to nudge one out of Earth’s way. Also, this type of radar instrument could be used on our own planet to look inside Earth’s polar caps and ice sheets to determine their stability.

Mars Express has been orbiting the Red Planet since December 2003. It carries seven scientific experiments, including MARSIS, which was built by the Italian Space Agency with cooperation from JPL and the University of Iowa.

Original News Source: ESA press release

Inflation Theory Takes a Little Kick in the Pants

Inflation theory proposes that the universe underwent a period of exponential expansion right after the Big Bang. One of the key predictions of inflation theory is the presence of a particular spectrum of “gravitational radiation”—ripples in the fabric of space-time that are really hard to detect but thought to exist. But a team of researchers has now found that gravitational radiation can be produced by a mechanism other than inflation. So this type of radiation, if eventually detected, won’t provide the conclusive evidence for inflation theory that was once was thought to be a certainty.

“If we see a primordial gravitational wave background, we can no longer say for sure it is due to inflation,” said noted astronomer Lawrence Krauss, from Case Western Reserve University.

Inflation theory first was proposed by cosmologist Alan Guth in 1981 as a means to explain some features of the universe that had previously baffled astronomers, such as why the universe is so close to being flat and why it is so uniform. Today, inflation remains the best way to theoretically understand many aspects of the early Big Bang universe, but most of the theory’s predictions are somewhat vague enough that even if the predictions were observed, they probably wouldn’t provide a clear-cut confirmation of the theory.

But gravitational radiation was considered one of the key predictions of inflation theory, and detection of this spectrum was regarded among physicists as “smoking gun” evidence that inflation did in fact occur, billions of years ago.

Gravitational radiation is a prediction of Einstein’s Theory of General Relativity. According to the theory, whenever large amounts of mass or energy are shifting around, it disrupts the surrounding space-time and ripples emanate from the region where the shift occurs. These ripples aren’t easily detected, but there is one experiment designed to look directly for this radiation, the Laser Interferometer Gravitational Wave Observatory (LIGO) in Livingston, Louisiana. The upcoming Planck Mission, set to launch in 2009 will look for it indirectly by looking at the cosmic microwave background.

Until now it was widely believed that detecting gravitational radiation in the form of polarized light from the CMB would confirm inflation theory, since it was thought inflation would be the only way this radiation could be produced. But Krauss and his team have raised the issue of whether this radiation can be unmistakably tied to inflation.

Krauss’s team proposes that a phenomenon called “symmetry breaking,” can also produce gravitational radiation. Symmetry breaking is a central part of fundamental particle physics, where a system goes from being symmetrical to a low energy state that is not symmetrical. Krauss’s explanation is that a “scalar field” (similar to an electric or magnetic field) becomes aligned as the universe expands. But as the universe expands, each region over which the field is aligned comes into contact with other regions where the field has a different alignment. When that happens the field relaxes into a state where it is aligned over the entire region and in the process of relaxing it emits gravitational radiation.

This is all fairly confusing, but the sweetened condensed version is that if gravitational radiation is ever detected, that event won’t necessarily verify inflation theory. Therefore, whether inflation theory can ever be confirmed remains to be seen.

Krauss’s paper “Nearly Scale Invariant Spectrum of Gravitational Radiation from Global Phase Transitions” is published in the Aprill 2008 Physical Review Letters.

Original News Source: Case Western Reserve University press release

Latest News on Apophis: 13 -year-old Boy Corrects NASA’s Estimates of Earth Impact — Not! (Update)

Annimation of Apophis.  Image Credit:  Osservatorio Astronomico Sormano
Update: It turns out this story is a fabrication and AFP didn’t check the facts with NASA as I suspected. According to the blog Cosmos4u, they talked with Don Yeomans at NASA’s NEO office and this is what Yeoman’s said about the news story of a 13-year old boy correcting NASA’s estimates of Apohpis impacting earth: “We have not corresponded with this young man and this story is absurd, a hoax or both. During its 2029 Earth close approach, Apophis will approach the Earth to about 38,900 km, well inside the geosynchronous distance at 42,240 km. However, the asteroid will cross the equatorial belt at a distance of 51,000 km – well outside the geosynchronous distance. Since the uncertainty on Apophis’ position during the Earth close approach is about 1500 km, Apophis cannot approach an Earth satellite. Apophis will not cross the moon’s orbital plane at the Moon’s orbital distance so it cannot approach the moon either.”

Also, the scientist mentioned in AFP’s story said he wasn’t conferred with either by the news agency. So don’t give any heed to this story that has been running amok around the internet.

But here’s our story on this as it originally ran: Here’s a story that supports the value of science fairs. And it also makes one wonder where else NASA’s decimal points might be off by a couple of places. One caveat on this news piece, however: as far as I know there hasn’t been an official NASA press release on this.

Reportedly, a 13-year-old German schoolboy doing research for a science competition found errors in NASA’s estimates on the chances of the asteroid Apophis colliding with Earth. The boy, Nico Marquardt used data from the Institute of Astrophysics in Potsdam to calculate that there was a 1 in 450 chance that the Apophis asteroid will collide with Earth. NASA had previously estimated the chances at only 1 in 45,000, but according to an AFP news release, NASA now acknowledges the kid is right. (Actually, no they don’t.)
Continue reading “Latest News on Apophis: 13 -year-old Boy Corrects NASA’s Estimates of Earth Impact — Not! (Update)”

Where In The World (and What World) Is This?

Anyone care to guess what orbiting spacecraft is responsible for taking this image, or even what world this is a picture of? At first glance, with all those craters, it could be Mars. However, the coloring isn’t quite right for the Red Planet. Is it a photograph of Mercury or an image of the moon?

OK, yes, this is an image of Earth, but you were wondering there for awhile, weren’t you! Interestingly enough, the white area is not snow, and the craters are not impact craters, but volcanic. And what spacecraft gets credit for the image? The International Space Station. This is one of the most recent images taken by the astronauts on board the ISS as part of the Earth Observatory program. A wonderful website, NASA’s Gateway to Astronaut Photography of Earth, hosts an incredible collection of photographs that astronauts have taken of our home planet.

Beginning with the Mercury missions in the early 1960s, astronauts have taken photographs of the Earth. As of April 7, 2008, this website has 759,527 views of the Earth, which includes 315,923 from the ISS. The site processes images coming down from the International Space Station on a daily basis, so the database is continually growing. The U.S. Destiny Laboratory module has a science window with high optical quality, which usually faces the Earth, and most of the ISS’s images are taken from that window on the world. On board the ISS is a nice selection of professional digital cameras, and a variety of lenses. One could spend hours (or days or a lifetime!) browsing through the striking photographs of Earth the astronauts have taken. The website also includes lots of information about each of the images, and a fun Where In the World quiz to test your geographical knowledge.

The image above is of the Harrat Khaybar volcanic field, a 14,000-square-kilometer area located in the western Arabian peninsula. The volcanic field was formed by eruptions along a 100-kilometer, north-south vent system over the past 5 million years. The most recent recorded eruption took place between 600-700 AD.

Harrat Khaybar contains a wide range of volcanic rock types and spectacular landforms, several of which are represented in this astronaut photograph. There are dark, fluid basalt lava flows, and the white deposits are sand and silt that accumulate in the depressions. There are lava domes and cones from the past volcanic activity.

The ISS astronauts take images daily of our planet. The image of Harrat Khaybar was taken on March 31, 2008, with a Kodak 760C digital camera fitted with a 400 mm lens, and is provided as part of the the ISS Crew Earth Observations experiment.

Original News Source: Earth Observatory website

New Technique Can Estimate Size and Frequency of Meteorite Impacts

News today from the National Science Foundation will have an impact on how scientists are able to study…. well, impacts. A team of geologists has developed a new way of determining the size and frequency of meteorites that have collided with Earth in the past. By studying sediments found on the ocean floor and looking for isotopes of the rare element osmium, scientists can now figure out not only when a meteorite impact occurred in Earth’s history, but also the size of the meteorite. One of the most exciting benefits of this new technique is the potential for identifying previously unknown impacts.

When meteorites collide with Earth, they carry a different osmium isotope ratio than the levels normally seen throughout the oceans.

“The vaporization of meteorites carries a pulse of this rare element into the area where they landed,” says Rodey Batiza of the National Science Foundation, which funded the research. “The osmium mixes throughout the ocean quickly. Records of these impact-induced changes in ocean chemistry are then preserved in deep-sea sediments.”

François Paquay, a geologist at the University of Hawaii at Manoa analyzed samples from two sites where core samples of the ocean floor were taken, one near the equatorial Pacific and another located off of the tip of South Africa. He measured osmium isotope levels during the late Eocene period, a time during which large meteorite impacts are known to have occurred.

“The record in marine sediments allowed us to discover how osmium changes in the ocean during and after an impact,” says Paquay.

The scientists believe this new approach to estimating impact size will become an important complement to a more well-known method based on iridium.

Paquay’s team also used this method to make estimates of impact size at the Cretaceous-Tertiary (K-T) boundary 65 million years ago. Since the osmium carried by meteorites is dissolved in seawater, the geologists were able to use their method to estimate the size of the K-T meteorite as four to six kilometers in diameter. The meteorite was the trigger, scientists believe, for the mass extinction of dinosaurs and other life forms.

But Paquay doesn’t believe this method will work for events larger than the K-T impact. With such a large meteorite impact, the meteorite contribution of osmium to the oceans would overwhelm existing levels of the element, making it impossible to sort out the osmium’s origin.
But it will be interesting to follow this to see if new, unknown impacts in Earth’s history can be discovered.

Original News Source: Eureka Alert