Posted on by Nancy Atkinson

Flags Still Standing at Several Apollo Landing Sites on the Moon

Caption: LROC image showing the illuminated side of the still standing American flag to be captured at the Apollo 17 landing site. Credit: NASA/GSFC/Arizona State University.

Mark Robinson, Principal Investigator of the Lunar Reconnaisance Orbiter Camera (LROC) says the most often-asked questions he gets about the images LRO has taken of the Moon are about pictures of the Apollo landing sites and what is visible. Especially, Robinson said, people want to know if the flags are still standing.

Previously, Robinson has said that while the flag poles are likely still standing, he didn’t think the flags themselves survived the harsh radiation of the lunar surface environment. But new images and video show that at some of the landing sites – Apollo 12, Apollo 16, and Apollo 17 – the flags must still be intact, because they are creating shadows on the surface.

“Personally I was a bit surprised that the flags survived the harsh ultraviolet light and temperatures of the lunar surface, but they did,” Robinson wrote on the LROC website. “What they look like is another question (badly faded?).”


Caption: The flag was captured in this image of the Apollo 16 site with the spacecraft slewed 15° towards the Sun; the shadowed side of the flag is seen by LROC. Credit: NASA/GSFC/Arizona State University.

James Fincannon, a NASA engineer from Glenn Research Center, combined LROC images of each Apollo site taken at roughly the same orientation but with different Sun angles to show the travel of shadows.

“Combined with knowledge of the Apollo site maps which show where the flag was erected relative to the Lander, long shadows cast by the flags at the three sites show that the these flags are still “flying”, held aloft by the poles,” Fincannon wrote.

And so, from the LROC images it is now certain that the American flags are still standing and casting shadows at all of the sites, except Apollo 11. Astronaut Buzz Aldrin reported that the flag was blown over by the exhaust from the ascent engine during liftoff of Apollo 11, and Robinson said that from the images of the Apollo 11 landing site, it looks like he was correct.


Caption: Enlargement of area surrounding Apollo 11 landing site. Credit: NASA/GSFC/Arizona State University

Robinson added that the most convincing way to see that the flags are still there, is to view a time series of LROC images taken at different times of day, and watch the shadow circle the flag (see movie below; the flag is just above the LM descent stage).

Read Fincannon’s story of his research on the flags.

Source: LROC website.

Posted on by Nancy Atkinson

Guest Post: Our Explosive Sun

Editor’s note: Pål Brekke is a Norwegian solar physicist with a doctorate from the University of Oslo in astrophysics and is now a senior advisor for the Norwegian Space Centre. He has written a new popular science book about the Sun, titled Our Explosive Sun; A Visual Feast of Our Source of Light and Life. Find out how you can win a copy of book here. Brekke has written this guest post for Universe Today.

The Sun has fascinated me for many years. This is perhaps not so strange since I walked my first steps at the solar observatory at Harestua, just north of Oslo. My dad worked there then. During my studies at the University in Oslo my advisors inspired me to spend time doing public outreach. And so it was my interest for sharing knowledge about the mysteries of the Sun that led to my writing this book.

This book presents the properties of the Sun, how it has fascinated humans for thousands of years, and how it affects our technological society. My hope is that this book will inspire an increased interest in the Sun and for natural science in general. The Sun is a perfect entrance to natural science, since it affects the Earth and humans in so many ways. Solar physics interacts with many other scientific fields, such as physics, chemistry, biology, and meteorology to mention a few.

The Sun


Caption: The Sun affects Earth in many ways. Image courtesy of Springer.

The Sun provides energy to all life on Earth and drives the climate system and is therefore very important to all of us. It powers photosynthesis in plants and is the ultimate source of all food and fossil fuel. However, storms on the Sun can also interfere with systems on Earth that our society depends upon.

Looking at the sky with the naked eye, the Sun seems static, placid, and constant. From ground the only noticeable variation in the Sun is its location (where it will rise and set today?). But the Sun gives us more than just a steady stream of warmth and light.

Situated 150 million kilometers away from us, the Sun is a huge thermonuclear reactor, fusing hydrogen atoms into helium and producing million degree temperatures and intense magnetic fields. Near the surface, the Sun is like a pot of boiling water, with bubbles of hot electrified gas. The steady stream of particles blowing away from the Sun is known as the solar wind. Blustering at 1.5 million kilometers per hour the solar wind carries a million tons of matter into space every second (that’s the mass of Utah’s Great Salt Lake).

Every 11 year the Sun undergoes a period of activity called the “solar maximum”, followed about 5 years later by a period of quiet called the “solar minimum”. During solar maximum there are many sunspots, and during solar minimum there are few. Thus, one way of tracking solar activity is by observing the number of sunspots. Sunspots are dark patches like freckles on the solar surface formed when magnetic field lines just below the Sun’s surface are twisted and poke through the solar surface. Sunspots can last from a few hours to several months, and a large sunspot can grow to several times the size of Earth. Though the Chinese recorded some observations as early as 28 B.C., scientists have been observing and recording sunspots since about 1610 when Galileo Galilei pointed his telescope towards the Sun.

Why do scientists care about Sunspots? Because they are visible signs of the turmoil inside the Sun that lead to space weather effects on Earth. Coronal mass ejections (CMEs) and solar flares are often associated with sunspot groups.

Over the next few years more solar storms will occur as the Sun approaches maximum activity in 2013.

Space Weather

Over the next few years more solar storms will occur as the Sun approaches maximum activity in 2013. And that sometimes these storms can cause damages here on Earth? In addition to creating the beautiful aurora, solar storms have many negative effects. The aurora is a manifestation of something violent happening in our atmosphere, where sometimes 1,500 gigawatts of electricity is generated. This is almost double the energy production in Europe!

Solar storms send out large amount of radiation, particles, gas, and magnetic fields into space, sometimes directly towards Earth. We are lucky that we are shielded from most of the hazardous radiation and particles. This is due to our atmosphere that is preventing UV and X-rays from reaching the ground, and our magnetosphere that is deflecting particles. The effects from solar storms are called space weather.

Until about 100 years ago solar storms could pass by without humans noticing much. However, today more than 1,000 satellites are operating in space. Our society depends on having these satellites work properly all the time. We use satellites for weather forecasts, communication, navigation, mapping, search and rescue, research, and military surveillance. The loss of a satellite and its signals can have serious consequences.

Solar storms affect important navigation systems and crucial radio communication. Passenger planes flying over the polar regions can lose radio contact with the flight controller. Satellite phones may stop working, and solar storms can knock out some electricity grids.

About the Author:

Pål Brekke has worked with state-of-the-art space-based solar telescopes since 1985 and has published over 40 peer-reviewed articles, 70 proceeding papers, and more than 30 popular science articles. For six years he was the ESA Deputy Project Scientist for the SOHO spacecraft.

Posted on by Nancy Atkinson

Win a Copy of “Our Explosive Sun”

For us humans, the Sun as seen with the naked eye appears as a static and quiet yellow disk in the sky. However, it is in fact a stormy and variable star and contributes much more than only light and heat. It is the source of the beautiful northern and southern lights and can affect our technology-based society in many ways. Want to find out more?

Thanks to Springer, Universe Today has 10 copies to give away of Pål Brekke’s book, Our Explosive Sun; A Visual Feast of Light and Life. To enter the contest, just send us an email with the subject line “Explosive Sun” and Fraser will choose 10 winners randomly from the all the entries received. The contest is open to anyone, from anywhere in the world.

The book provides a detailed introduction to the dynamics of the Sun and how it affects Earth, both physically and culturally. It includes stunning visuals and
several images never published before. Also included are animations, videos and a PowerPoint presentation as part of SpringerExtras.

You can read a guest post here on UT about the Sun by Brekke.

Thanks again to Springer for sponsoring this contest.

Posted on by Nancy Atkinson

Fish in Space: Space Station Gets an Aquarium

Caption: The Aquatic Habitat will enable the study of fish aboard the International Space Station. Credit: JAXA.

How does microgravity impact marine life? One of the more unique experiments on board the Japanese HTV-3 supply ship, scheduled to be berthed to the International Space Station’s Harmony node at 12:00 UTC on July 27, 2012, is the Aquatic Habitat, or AQH. It is basically an aquarium designed to function in space, complete with fish called Medaka. While there are several experiments planned for the AQH, surely the astronauts will enjoy watching their newest “pets” on the ISS.

Sponsored by the Japanese Space Agency, or JAXA, the AQH is a closed-water circulatory system, which provides a new facility option for station research. Scientists will use the habitat to study small, freshwater fish on orbit, the Medaka (Oryzias latipes).

This is not the first time fish have been part of a space mission. Versions of the AQH flew on space shuttle missions STS-47, STS-65, and STS-90. The current system’s design upgrades are based on lessons learned from these missions.

Scientists have multiple studies planned to look at the impacts of radiation, bone degradation, muscle atrophy, and developmental biology. The investigations could last up to 90 days and provide data that may lead to a better understanding of related human health concerns here on Earth.

“We think studies on bone degradation mechanisms and muscle atrophy mechanisms are applicable to human health problems, especially for the aging society,” said Nobuyoshi Fujimoto, associate senior engineer at JAXA’s Space Environment Unitization Center.

Fujimotoe said the Medaka fish are ideal specimens for many reasons. They are transparent, making it easy to view the inner workings of their organs. They also breed quickly and easily in microgravity environments, enabling multi-generation studies. Researchers can take advantage of a variety of genetic modifications to these fish, as well. Finally, scientists already have all of the Medaka genome identified, which makes it easier to recognize any alterations to the fishes’ genes, due to factors like space radiation.

The AQH will reside in the Japanese Experiment Module, or JEM, which is also known as Kibo, or “hope” in Japanese. It will attach to a multipurpose small payload rack for power and housing.

This habitat will provide automatic feeding for the fish, air-water interface, temperature control, and a specimen sampling mechanism. There will be two chambers for habitation, each sized at 15 by 7 by 7 cm, holding about 700 cc water and a stabilized area for oxygen that will enable fish to “peck” air. LED lights will simulate day and night cycles, while two video cameras record images of the fish to downlink to the ground, upon request.

This facility includes an improved water circulation system that monitors water conditions, removing waste while ensuring proper pressure and oxygen flow rates.

“In order to keep water quality in good condition for the health of the fish, we had to do many tests on the filtration system, especially the bacteria filter,” said Fujimoto. “The special bacteria filter purifies waste materials, such as ammonia, so that we can keep fish for up to 90 days. This capability will make it possible for egg-to-egg breeding aboard station, which means up to three generations may be born in orbit. This would be a first for fish in space.”

Hopefully the crew will enjoy viewing and monitoring the fish, and those of us on Earth look forward to some live views of the fish in microgravity.

Source: NASA

Posted on by Jason Major

Europe’s Plans to Visit the Moon in 2018

The European Space Agency is aiming for the Moon with their Lunar Lander mission, anticipated to arrive on the lunar surface in 2018. Although ESA successfully put a lander on Titan with the Huygens probe in 2005, this will be the first European spacecraft to visit the surface of Earth’s Moon.

Although Lunar Lander will be an unmanned robotic explorer, the mission will be a forerunner to future human exploration of the Moon as well as Mars. Lunar Lander will use advanced technologies for autonomous landing and will be able to determine the best location for touchdown on its own, utilizing lasers to avoid obstacles on the Moon’s surface.

With no GPS on the Moon, Lunar Lander will navigate by digitally imaging the surface on the fly. Landing will be accomplished via thrusters, which were successfully tested earlier this year at a test chamber in Germany.

Lunar Lander’s destination will be the Moon’s south pole, where no exploration missions have ever landed. Once on the lunar surface, the Lander will investigate Moon dust using a robotic arm and a suite of onboard diagnostic instruments, sending data and images back to scientists on Earth for further study.

Watch a video of the Lunar Lander mission below, from launch to landing.

Read more about Lunar Lander on the ESA site here.

Images and video: ESA

Posted on by Nancy Atkinson

DARPA Moving Ahead with Building Zombie Frankensatellites

Caption: Phoenix satellite concept. Credit: DARPA

“Alien” meets “Bride of Frankenstein” and “Night of the Living Dead?” Straight from a possible sci-fi/horror movie mashup, the Defense Advanced Research Projects Agency (DARPA) wants to harvest components from dead, non-working “zombie” satellites to build new ones in space, all done remotely via a grasping, mechanical arm.

The agency would like to have the first keystone mission of what is called the Phoenix Program up and running by 2015, and they recently announced that several companies and NASA’s Jet Propulsion Lab have won a share of a $36 million contract award to help develop the technology to assemble new satellites from old, dead ones.

This project would harvest larger working parts, such as antennas and solar arrays from satellites that have otherwise have failed and are still in geosynchronous orbit, 35,000 kilometers (22,000 miles) above Earth. DARPA envisions robotically removing and re-using these parts from decommissioned satellites by developing a new class of very small ‘satlets,’ similar to nano satellites, which could “ride along” other commercial satellite launches, greatly reducing launch costs, DARPA says.

The satlets would attach themselves to the antenna or solar array of a non-functional satellite, remove the part and move it to a different orbit where a satellite servicing spacecraft is waiting to robotically operate on and build a new satellite while in orbit. The servicing satellite would be equipped with grasping mechanical arms for removing the satlets and components. These unique space tools are what needs to be developed for the program.

The robotic arms/grappling tools will be controlled remotely from Earth. The pieces will then be reconfigured into a new free-flying space system and operated independently to demonstrate the concept of space re-use.

DARPA is interested in building communication satellites to provide 24-hour communication capabilities for the military.

“Today, when a communication satellite fails, it usually means the expensive prospect of having to launch a brand new replacement communication satellite,” DARPA’s Phoenix Program webpage says. “The goal of the Phoenix program is to develop and demonstrate technologies to cooperatively harvest and re-use valuable components from retired, nonworking satellites in GEO and demonstrate the ability to create new space systems at greatly reduced cost.”

Among the companies that have a share in creating the components needed to make Phoenix a reality are Altius Space Machines, Space Systems/Loral; Intelsat; MacDonald, Dettwiler and Associates; Honeybee Robotics; and JPL.

Some of the technology DARPA expects to be built for the Phoenix program include:

Radiation tolerant micro-electronics and memory storage
Industrial robotics end effectors and tool changeout mechanisms and techniques
Computer-assisted medical robotics micro-surgical tele-presence, tools and imaging
Remote imaging/vision technologies

Watch DARPA’s video on the Phoenix Program:

For more information, see the DARPA Phoenix webpage.

Posted on by Nancy Atkinson

Bright Stars Don’t Like to Be Alone

Caption: New research using data from European Southern Observatory telescopes, including the Very Large Telescope, has revealed that the hottest and brightest stars, known as O stars, are often found in close pairs. Credit: ESA, NASA, H. Sana (Amsterdam University), and S.E. de Mink (STScI)

Like humans, stars seem to prefer the company of companions. A new study using the Very Large Telescope reveals that most very bright, high-mass O-type stars do not live alone. Surprisingly, almost three-quarters of these stars have a close companion star, far more than previously thought. But sometimes – also like humans – the relationship between companion stars can turn a little ugly, with one star becoming dominant and even disruptive by stealing matter from the other, or doing a hostile takeover.


An international team of astronomers have found that some stars will virtually suck the life out of another, and about one-third of the time, a pair of stars will ultimately merge to form a single star.

The stars included in this study are some of the biggest, brightest stars which have very high temperatures. They live fast and die young, and in their lives play a key role in the evolution of galaxies. by, which drive the evolution of galaxies. They are also linked to extreme phenomena such as gamma-ray bursts.

“These stars are absolute behemoths,” said Hugues Sana, from the University of Amsterdam, The Netherlands, lead author of the study. “They have 15 or more times the mass of our Sun and can be up to a million times brighter. These stars are so hot that they shine with a brilliant blue-white light and have surface temperatures over 54,000 degrees Fahrenheit (30,000 degrees C).”

The astronomers studied a sample of 71 O-type single stars and stars in pairs (binaries) in six nearby young star clusters in the Milky Way.
By analyzing the light coming from these targets in greater detail than before, the team discovered that 75 percent of all O-type stars exist inside binary systems, a higher proportion than previously thought, and the first precise determination of this number. More importantly, though, they found that the proportion of these pairs that are close enough to interact (through stellar mergers or transfer of mass by so-called vampire stars) is far higher than anyone had thought, which has profound implications for our understanding of galaxy evolution.

O-type stars make up just a fraction of a percent of the stars in the universe, but the violent phenomena associated with them mean they have a disproportionate effect on their surroundings. The winds and shocks coming from these stars can both trigger and stop star formation, their radiation powers the glow of bright nebulae, their supernovae enrich galaxies with the heavy elements crucial for life, and they are associated with gamma-ray bursts, which are among the most energetic phenomena in the universe. O-type stars are therefore implicated in many of the mechanisms that drive the evolution of galaxies.

“The life of a star is greatly affected if it exists alongside another star,” said Selma de Mink of the Space Telescope Science Institute, in Baltimore, Md., a co-author of the study. “If two stars orbit very close to each other they may eventually merge. But even if they don’t, one star will often pull matter off the surface of its neighbor.”

Mergers between stars, which the team estimates will be the ultimate fate of around 20 to 30 percent of O-type stars, are violent events. But even the comparatively gentle scenario of vampire stars, which accounts for a further 40 to 50 percent of cases, has profound effects on how these stars evolve.

Until now, astronomers mostly considered that closely orbiting massive binary stars were the exception, something that was only needed to explain exotic phenomena such as X-ray binaries, double pulsars, and black hole binaries. The new study shows that to properly interpret the universe, this simplification cannot be made: these heavyweight double stars are not just common, their lives are fundamentally different from those of single stars.

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For instance, in the case of vampire stars — where the smaller, lower-mass star is rejuvenated as it sucks the fresh hydrogen from its companion — its mass will increase substantially and it will outlive its companion, surviving much longer than a single star of the same mass. The victim star, meanwhile, is stripped of its envelope before it has a chance to become a luminous red supergiant. Instead, its hot, blue core is exposed. As a result, the stellar population of a distant galaxy may appear to be much younger than it really is: both the rejuvenated vampire stars, and the diminished victim stars become hotter, and bluer in color, mimicking the appearance of younger stars. Knowing the true proportion of interacting high-mass binary stars is therefore crucial to correctly characterize these faraway galaxies.

“The only information astronomers have on distant galaxies is from the light that reaches our telescopes. Without making assumptions about what is responsible for this light we cannot draw conclusions about the galaxy, such as how massive or how young it is. This study shows that the frequent assumption that most stars are single can lead to the wrong conclusions,” said Sana.

Understanding how big these effects are, and how much this new perspective will change our view of galactic evolution, will need further work. Modeling binary stars is complicated, so it will take time before all these considerations are included in models of galaxy formation.

The paper was published in the July 27 issue of the journal Science.

Paper by: Sana, de Mink, et al. (PDF document)

Sources: ESO, HubbleSite

Posted on by Jenny Winder

Beneath the Mask, Titan looks Surprisingly Smooth and Youthful

Images from the Cassini mission show river networks draining into lakes in Titans north polar region. Credit: NASA/JPL/USGS.

Caption: Images from the Cassini mission show methane river networks draining into lakes in Titan’s north polar region. Credit: NASA/JPL/USG

Saturn’s largest moon, Titan has long been hidden beneath the thick shroud of its methane- and nitrogen-rich atmosphere. That all changed in 2004 when NASA’s Cassini mission was able to penetrate the haze and sent back detailed radar images of the surface. These showed an icy terrain, carved over millions of years, by rivers similar to those found here on Earth. However, Titan’s surface doesn’t look as old and weather-beaten as it should. The rivers have caused surprisingly little erosion and there are fewer impact craters than would be expected. So what is the secret to Titan’s youthful complexion?

Titan is around four billion years old, roughly the same age as the rest of the solar system. But the low number of impact craters put estimates of its surface at only between 100 million and one billion years old.

Researchers at MIT and the University of Tennessee at Knoxville have analyzed images of Titan’s river networks and suggest two possible explanations: either erosion on Titan is extremely slow, or some recent phenomena has wiped out older surface features.

Taylor Perron, the Cecil and Ida Green Assistant Professor of Geology at MIT explains, “It’s a surface that should have eroded much more than what we’re seeing, if the river networks have been active for a long time. It raises some very interesting questions about what has been happening on Titan in the last billion years.”

Perron suggests that geological processes on Titan may be like those we see here on Earth. Here too, impact craters are scarce, as plate tectonics, erupting volcanoes, advancing glaciers and river networks reshaped our planet’s surface over billions of years, so, on Titan, tectonic upheaval, cryovolcanic eruptions, erosion and sedimentation by rivers could be altering the surface.

Discovering which processes are at work is not easy. The images from Cassini are like aerial photos but with much coarser resolution. They are flat, with no information about a surface elevation or depth.

Perron and MIT graduate student Benjamin Black analyzed the images and mapped 52 prominent river networks from four regions on Titan. They then compared the images with a model of river network evolution developed by Perron. Their data depicts the evolution of a river over time, taking into account variables such as the strength of the underlying material and the rate of flow through the river channels. As a river erodes, it transforms from a long, spindly thread into a dense, treelike network of tributaries. Titan’s river networks have maintained their long and spindly composition. They compare with recently renewed landscapes here including volcanic terrain on the island of Kauai and recently glaciated landscapes in North America.

Besides Earth, Titan is the only world with an active hydrologic cycle forming active river networks. Titan’s surface temperature may be about 94 K and its rivers run with liquid methane but as Perron says “It’s a weirdly Earth-like place, even with this exotic combination of materials and temperatures, and so you can still say something definitive about the erosion. It’s the same physics.”

Below is a video of Black and Perron explaining their research:

Find out more

Posted on by Jason Major

Mercury’s Many Colors

Although composited from expanded wavelengths of light, this wide-angle image from NASA’s MESSENGER spacecraft shows the amazing variation of colors and tones to be found on Mercury’s Sun-scoured surface.


This scene lies between Mercury’s Moody and Amaral craters, spanning an area of about 1200 km (745 miles). The patch of dark blue Low Reflectance Material (LRM) in the upper left of the image and the bright rayed crater on the right make this a diverse view of Mercury’s surface. Note the curious small, dark crater just below the bright rayed crater on the right.

Dark LRM material is thought to indicate the presence of a mineral called ilmenite, which is composed of iron and titanium and has been revealed through volcanic, cratering and erosion processes.

More Mercury images: Postcards from the (Inner) Edge

Did you know that until MESSENGER arrived in 2008 half of Mercury had never been seen? And that although Mercury is the closest planet to the Sun there may still be water ice on its surface? Learn more about these and other fascinating facts about Mercury here.

Image: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington