Posted on by Fraser Cain

Mars Reconnaissance Orbiter Ready for Thursday Launch

The Mars Reconnaissance Orbiter. Image credit: NASA Click to enlarge
NASA’s Mars Reconnaissance Orbiter is ready for a morning launch on Thursday, Aug. 11. The spacecraft will arrive at Mars in March 2006 for a mission to understand the planet’s water riddles and to advance the exploration of the mysterious red planet.

The mission’s first launch opportunity window is 4:50 to 6:35 a.m. PDT, Thursday. If the launch is postponed, additional launch windows open daily at different times each morning through August. For trips from Earth to Mars, the planets move into good position for only a short period every 26 months. The best launch position is when Earth is about to overtake Mars in their concentric racing lanes around the Sun.

“The teams preparing this orbiter and its launch vehicle have done excellent work and kept to schedule. We have a big spacecraft loaded with advanced instruments for inspecting Mars in greater detail than any previous orbiter, and we have the first Atlas V launch vehicle to carry an interplanetary mission. A very potent and exciting combination,” said NASA’s Mars Exploration Program Director Doug McCuistion.

The mission will lift off from Launch Complex 41, Cape Canaveral Air Force Station, Fla. It is the first government launch of Lockheed Martin’s Atlas V launch vehicle. “We’re ready to fly, counting down through final procedures,” said Chuck Dovale, director for expendable-launch-vehicle launches at NASA Kennedy Space Center, Fla.

When the Mars Reconnaissance Orbiter arrives in March, it begins a half-year “aerobraking” process. The spacecraft will gradually adjust the shape of its orbit by using friction from carefully calculated dips into the top of the Martian atmosphere. The mission?s primary science phase starts in November 2006.

“Mars Reconnaissance Orbiter will give us several times more data about Mars than all previous missions combined,” said James Graf, project manager for the mission at NASA’s Jet Propulsion Laboratory, Pasadena Calif.

Researchers will use the data to study the history and distribution of Martian water. Learning more about what has happened to the water will focus searches for possible past or present Martian life. Observations by the orbiter will also support future Mars missions by examining potential landing sites and providing a communications relay between the Martian surface and Earth.

The craft can transmit about 10 times as much data per minute as any previous Mars spacecraft. This will serve both to convey detailed observations of the Martian surface, subsurface and atmosphere by the instruments on the orbiter and enable data relay from other landers on the Martian surface to Earth. NASA plans to launch the Phoenix Mars Scout in 2007 to land on the far northern Martian surface. NASA is also developing an advanced rover, the Mars Science Laboratory, for launch in 2009.

The mission is managed by JPL, a division of the California Institute of Technology, Pasadena, Calif., for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft and is the prime contractor for the project.

NASA’s Launch Services Program at the Kennedy Space Center is responsible for government engineering oversight of the Atlas V, spacecraft/launch vehicle integration and launch day countdown management.

For more information about the Mars Reconnaissance Orbiter on the Web, visit: http://www.nasa.gov/mro.

Original Source: NASA News Release

Posted on by Fraser Cain

Tiny Epimetheus Outside the Rings

Saturn’s moon Epimetheus just beneath the ring. Image credit: NASA/JPL/SSI Click to enlarge.
Saturn’s moon Epimetheus is seen here from just beneath the ring plane, along with Saturn’s intriguing F ring. The bright, knotted core of the F ring is flanked on both sides by thin, dusty strands. The outer part of the A ring is visible at the left. Epimetheus is 116 kilometers (72 miles) across.

Part of the little moon’s night side is illuminated by reflected light from the planet. For a closer view of Epimetheus see Epimetheus: Up-Close and Colorful.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 30, 2005, at a distance of approximately 1.8 million kilometers (1.1 million miles) from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 93 degrees. Resolution in the original image was 11 kilometers (7 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Original Source: NASA/JPL/SSI News Release

Posted on by Fraser Cain

Delays for the Earth’s Oxygen Atmosphere

Looking down on Earth. Image credit: NASA Click to enlarge
A number of hypotheses have been used to explain how free oxygen first accumulated in Earth’s atmosphere some 2.4 billion years ago, but a full understanding has proven elusive. Now a new model offers plausible scenarios for how oxygen came to dominate the atmosphere, and why it took at least 300 million years after bacterial photosynthesis started producing oxygen in large quantities.

The big reason for the long delay was that processes such as volcanic gas production acted as sinks to consume free oxygen before it reached levels high enough to take over the atmosphere, said Mark Claire, a University of Washington doctoral student in astronomy and astrobiology. Free oxygen would combine with gases in a volcanic plume to form new compounds, and that process proved to be a significant oxygen sink, he said.

Another sink was iron delivered to the Earth’s outer crust by bombardment from space. Free oxygen was consumed as it oxidized, or rusted, the metal.

But Claire said that just changing the model to reflect different iron content in the outer crust makes a huge difference in when the model shows free oxygen filling the atmosphere. Increasing the actual iron content fivefold would have delayed oxygenation by more than 1 billion years, while cutting iron to one-fifth the actual level would have allowed oxygenation to happen more than 1 billion years earlier.

“We were fairly surprised that we could push the transition a billion years in either direction, because those levels of iron in the outer crust are certainly plausible given the chaotic nature of how Earth formed,” he said.

Claire and colleagues David Catling, a UW affiliate professor in atmospheric sciences, and Kevin Zahnle of the National Aeronautics and Space Administration’s Ames Research Center in California will discuss their model tomorrow (Aug. 9) in Calgary, Alberta, during the Geological Society of America’s Earth System Processes 2 meeting.

Earth’s oxygen supply originated with cyanobacteria, tiny water-dwelling organisms that survive by photosynthesis. In that process, the bacteria convert carbon dioxide and water into organic carbon and free oxygen. But Claire noted that on the early Earth, free oxygen would quickly combine with an abundant element, hydrogen or carbon for instance, to form other compounds, and so free oxygen did not build up in the atmosphere very readily. Methane, a combination of carbon and hydrogen, became a dominant atmospheric gas.

With a sun much fainter and cooler than today, methane buildup warmed the planet to the point that life could survive. But methane was so abundant that it filled the upper reaches of the atmosphere, where such compounds are very rare today. There, ultraviolet exposure caused the methane to decompose and its freed hydrogen escaped into space, Claire said.

The loss of hydrogen atoms to space allowed increasingly greater amounts of free oxygen to oxidize the crust. Over time, that slowly diminished the amount of hydrogen released from the crust by the combination of pressure and temperature that formed the rocks in the crust.

“About 2.4 billion years ago, the long-term geologic sources of oxygen outweighed the sinks in a somewhat permanent fashion,” Claire said. “Escaping to space is the only permanent escape that we envision for the hydrogen, and that drove the planet to a higher oxygen level.”

The model developed by Claire, Catling and Zahnle indicates that as hydrogen atoms stripped from methane escaped into space, greenhouse conditions caused by the methane blanket quickly collapsed. Earth’s average temperature likely cooled by about 30 degrees Celsius, or 54 degrees Fahrenheit, and oxygen was able to dominate the atmosphere because there was no longer an overabundance of hydrogen to consume the oxygen.

The work is funded by NASA’s Astrobiology Institute and the National Science Foundation’s Integrative Graduate Education and Research Traineeship program, both of which foster research to understand life in the universe by examining the limits of life on Earth.

“There is interest in this work not just to know how an oxygen atmosphere came about on Earth but to look for oxygen signatures for other Earth-like planets,” Claire said.

Original Source: UW News Release

Posted on by Fraser Cain

Heavy Bombardments Make the Best Homes… for Microbes

Hills of impact melt breccias. Image credit: Gordon Osinski/CSA Click to enlarge
Meteor impacts are generally regarded as monstrous killers and one of the causes of mass extinctions throughout the history of life. But there is a chance the heavy bombardment of Earth by meteors during the planet’s youth actually spurred early life on our planet, say Canadian geologists.

A study of the Haughton Impact Crater on Devon Island, in the Canadian Arctic, has revealed some very life-friendly features at ground zero. These include hydrothermal systems, blasted rocks that are easier for microbes to inhabit, plus the cozy, protected basin created by the crater itself. If true, impact craters could represent some of the best sites to look for signs of past or present life on Mars and other planets.

A presentation on the biological effects of impacts is scheduled for Monday, 8 August, at Earth System Processes 2, a meeting co-convened by the Geological Society of America and Geological Association of Canada this week in Calgary, Alberta, Canada.

The idea that meteor impacts could benefit or even create conditions suitable for the beginning of early life struck Canadian Space Agency geologist Gordon Osinski while he and colleagues were conducting a geological survey of the 24-kilometer (15-mile) diameter Haughton Crater. Along the rim of the crater they noticed what looked like fossilized hydrothermal pipes, a few meters in diameter.

“That set the bells ringing about possible biological implications,” said Osinski. Hydrothermal systems are thought by many people to be the favourable places for life to evolve.”

Detailed mineralogical analyses have since revealed that when the Haughton meteor smacked into the icy ground 23 million years ago it created not only a crater, but fractured the ground in such a way as to create a system of steamy hydrothermal springs reaching temperatures of 250 degrees C. The heat appears to have gradually dropped over a period of tens of thousands of years, the researchers report.

Besides providing heat and cracking the ground, the impact also created pore spaces in otherwise dense granitic rocks, giving microbes more access to the minerals and the surfaces inside the rocks ? basically more real estate and more supplies.

The shocked rocks are also more translucent, which would be beneficial to organisms that possessing with any photosynthetic capabilities.

A crater shape itself also might serve as a protective environment, says Osinski. As such, impact craters are also good places to store evidence of past life. On Earth many craters fill with water and become lakes. Lakes accumulate sediments, the layers of which are a geological archive of the time after the crater formed. The Haughton Impact crater, for instance, contains the only Miocene-age sediments in the entire Canadian Arctic.

“One of the most interesting aspects of the Haughton Impact Crater is that it’s in a polar desert,” said Osinski. The dry, frigid weather makes for a barren landscape that’s easy to study, he said. The same features make it one of the more Mars-like places on Earth.

“Most people put impacts with mass extinctions,” said Osinski. “What we’re trying to say is that following the impact, the impact sites are actually more favorable to life than the surrounding terrain.”

It’s interesting to note, says Osinski, that on Earth the heaviest meteor bombardment of the planet happened at about the same time as life is believed to have started: around 3.8 billion years ago. Impact craters of that age were long ago erased on Earth by erosion, volcanic resurfacing and plate tectonics.

But other planets and moons – including Mars – still bear the cosmic scars of that early debris-clogged period in the solar system. It may be possible, therefore, that the best places to look for at least fossil evidence of life on Mars is inside those very same craters, he said.

“What we’re doing is trying to narrow down the search area,” said Osinski.

Original Source: GSA News Release

Posted on by Fraser Cain

10th Planet Controversy

Artist illustration of the newly discovered 10th planet. Image credit: NASA/JPL. Click to enlarge.
At the same time, another team led by astronomer Mike Brown of Caltech reported they had been observing 2003 EL61 for almost a year, but were waiting to analyze data from the Spitzer Space Telescope before announcing the discovery.

“There is no question that the Spanish group is rightly credited with discovery,” Brown stated on his personal website. “Even if they had found the object only this year and announced its existence, they would still be considered the rightful discovers. We took a chance that no one else would find it while we were awaiting our observations from the Spitzer Space Telescope. We were wrong! And we congratulate our colleagues on a very nice discovery.”

But just hours after that, Brown announced to the media the discovery of two other big TNOs, designated as 2003UB313 and 2005 FY9. Regarding the first one, he stated that it’s about three times as far from the Sun as Pluto, and “it’s definitely bigger” than the ninth planet.

Brown’s team discovered 2003 ub313 on January 8th, but wanted to further analyze their observations. However, they “were forced to announce their results on Friday evening because word had leaked out” he said.

“In mid-July, short abstracts of scientific talks to be given at a meeting in September became available on the web. We intended to talk about the object now known as 2003 EL61, which we had discovered around Christmas of 2004, and the abstracts were designed to whet the appetite of the scientists who were attending the meeting. In these abstracts we call the object a name that our software automatically assigned, K40506A -the first Kuiper belt object we discovered in data from 2004/05/06, May 6th-. Using this name was a very very bad idea on our part.”

“Unbeknownst to us, some of the telescopes that we had been using to study this object keep open logs of who has been observing, where they have been observing, and what they have been observing. A two-second Google search of “K40506A” immediately reveals these observing logs”.

According to Brown, from the moment the abstracts became public, anyone with an Internet connection and a little curiosity about the “K40506A” object could have found out where it was.

Brown was quick to point that he believes the fact that this discovery happened days after the data were potentially available on the Web is a coincidence. But “some people in the community privately expressed their concerns to me that this coincidence was too good to be true and wanted to know if there was any possible way that anyone could have found out the location of our object,” he added.

At this point, Brown contacted Brian Marsden at the International Astronomical Union’s Minor Planet Center (MPC). Brown told him confidentially about the two objects not yet announced (2003 UB313 and 2005 FY9), expressed his concerns that someone might be able to find their data and attempt to claim credit for discovering these objects, and sought advice.

Marden found that someone had already used the website of the MPC to access past observations of one of the objects and predict its location for that night. The past observations were precisely the logs from the telescope that Brown’s group had been using. “We had no choice but to hastily pull together a press conference which was held at 4pm on the last Friday in July, perhaps the single best time to announce news that you want no one to hear”, said Brown.

However, some astronomers have a very different opinion about Brown’s announcement.

“The group of Dr. Brown decided, as in previous cases, not to make public its detection until they finished their observations and their research work, and until the object was in conjunction with the Sun so that other people couldn’t observe it,” stated Dr. Javier Licandro in an e-mail sent to a Spanish-speaking astronomy mailing list. Licandro works at the Isaac Newton Group of Telescopes and the Instituto de Astrof?sica de Canarias, in Spain.

“They did it before with Sedna. But this time, by taking this ‘doubtful’ risk, they lost all the rights on the discovery of that object. Even more, their policy is, at least, criticizeable.”

“Due to the detection of 2003 EL61 by Ortiz et. al., and because of the fiasco that this has represented for Brown et. al., they decided to go public ‘ipso factum’ with their discoveries of two other objects that they knew at least from six months ago, 2005 FY y 2003 UB313,” said Licandro.

Contacted by AstronomiaOnline.com, Brown wouldn’t want to elaborate on Licandro’s comments. “I like Javier. It is unfortunate he feels the need to make such remarks,” he said.

But it didn’t take long for Ortiz to air his own feelings about the situation. “With technology many times more advanced than our own, Brown’s team had discovered three big objects many months ago, but they were hiding their findings from the international scientific community, as they did before with Quaoar and Sedna,” he declared to the Spaniard paper ABC.

“This secrecy was useful to Brown, as it allowed him to study the object in detail and exclusively. But his actions harm science and don’t follow the established procedures that imply notifying the existence of a new object to the astronomical community as soon as it’s discovered,” added Ortiz.

Brown indicated that he didn’t get that statement from Ortiz himself, so he would not want to comment on it directly. However, asked again by AstronomiaOnline.com, he said: “In general, there certainly are people who have that opinion, to which they are entitled. I, however, cannot think of any area of science in which an ‘established procedure’ is to announce a discovery with no time for thought and analysis. Anyone who feels otherwise is welcome to go and find these objects themselves -as did Ortiz- and get the credit for their own discoveries.”

Written by Ricardo J. Tohmé for Astronom?aOnline. If you want to read the original article in Spanish, click here.

Posted on by Mark Mortimer

Book Review: Defining NASA

Most people know that NASA is the agency of the United States that pursues space activities. Though sounding simple enough, this statement can lead to pitfalls just like in moving mountains. First off, what, or more precisely, where exactly does space begin and end? Further, what are the space activities and equipment for which NASA is responsible? Should this include all launch vehicles, launch pads, and space stations? Are only they responsible for earth observation, travelling to other planets and understanding the meaning of life? As Kay succinctly points out, there is a fine and constantly changing line that delegates duties to NASA, other parties, or to no one at all.

In support of the discussion of space policy, Kay begins by defining elements of his craft. Within his analytical framework, a government policy includes definition and information (e.g. what is a mountain), ownership (e.g. who’s responsible for the mountain) and goals (e.g. move what to where). In developing this framework he then continually refers back to it while discussing the policies of NASA from inception to about the year 2000.

Kay begins with assessing Eisenhower’s interests. His considered space solely as another theatre of warfare. He raises the subterfuge regarding the use of the International Geophysical Year as evidence. Also he draws on the administration’s apparent lack of interest in Soviet progress with Sputnik and Gagarin. Kay then argues that public perception, massage and crafted by political leaders, turned this situation into a nation security issue. With the horrific spectre of space based weapons breathing down their necks, people’s pocket books opened and the ‘space race’ arose. Further, Kay demonstrates how space achievements were even a noticeable gauge in the opinions of third world countries. That is, by being aligned with national security, space activities could also be justified as a means of foreign diplomacy.

This big change in space policy, as Kay notes, came about due to outside events, principally the advances of the Soviets. The next change occurred because the space program met its objectives. National and world opinion considered the US to have a better space program, hence the space race was won and national security no longer drove space policy. Kay argues that this began in 1965 and supports this with discussions about budgets, appropriations and directives from the political leaders. The consequence was that NASA became a fully operative program without a policy.

Here Kay demonstrates the main challenges of crafting policy in a democracy. In returning to his analytical framework, he shows that programs bereft of policy become unfocused and are primarily subject to political and budgetary forces. Because of this new direction, the space shuttle was born as it was to dramatically lower the cost to access space. Next, the space station was born due to political issues. Then, Kay leaves the reader hanging as he quite rightly points out that NASA still is without an effective policy.

There is nothing new in Kay’s historical view of space activities. Its values is in the novel assessment of space policy purely from a political science perspective. Kay’s writing is very clear and his arguments are well supported with reason and references. There may be too many references for some as it, together with the indices and table of contents, add up to almost a third of the book. Still, the text appears as a very open, honest and accurate assessment of the United State’s space policy through the previous fifty years.

The space agency NASA has a carefully constructed image of being an expert on space. In so doing they expect that anyone interested in space would come to their door. However as shown in W.D. Kay’s book, Defining NASA – The Historical Debate Over the Agency’s Mission, this is not sufficient. As he writes, NASA, like any government program, must continually have a viable, effective policy to be as effective a program as it was in its early years.

Read more reviews online, or purchase a copy from Amazon.com.

Review by Mark Mortimer.

Posted on by Fraser Cain

Discovery Lands Safely at Edwards

Discovery’s touchdown. Image credit: NASA Click to enlarge
Discovery glided to a pre-dawn landing at Edwards Air Force Base in California this morning concluding a journey of 5.8 million miles, touching down at 7:11 a.m. CDT.

The landing marked the sixth night landing at Edwards Air Force Base, and the 50th time overall that a Shuttle concluded its mission in the California desert.

Commander Eileen Collins and Pilot Jim Kelly, assisted by Mission Specialist Steve Robinson, began Discovery?s return to earth by firing the spacecraft’s orbital maneuvering system engines to slow its speed and begin its descent. Discovery’s ground track took it from the firing of the 2 minute, 42-second deorbit burn at 6:06 a.m. over the western Indian Ocean, traveling in a loop around Australia, then northeast across the Pacific, across the California coast north of Los Angeles and then to Edwards.

Persistent thunderstorms at the primary landing site in Florida resulted in a wave-off of two opportunities to return to the launch site today.

The STS-114 flight of Discovery with Collins, Kelly, Robinson and Mission Specialists Soichi Noguchi of the Japanese Aerospace Exploration Agency, Andy Thomas, Wendy Lawrence and Charlie Camarda provided unprecedented information on the condition of an orbiter in space. Noguchi and Robinson did three successful spacewalks at the International Space Station and Discovery transported tons of equipment and supplies to and from the Station.

From the Station, Commander Sergei Krikalev and NASA Science Officer John Phillips sent their congratulations to Discovery?s crew and the flight control team in Houston.

Discovery?s crew will have a welcome home ceremony at 3 p.m. Wednesday at Houston?s Ellington Field.

Original Source: NASA News Release

Posted on by Fraser Cain

What’s Up This Week – August 8 – August 14, 2005

The Moon and Venus Credit: Robert Sandy
Monday, August 8 – About an hour after sunset, look for the crescent Moon low in the west/southwest for northern hemisphere viewers. Check out Venus less than a fist’s width to its lower right and Jupiter less than a handspan to upper left. We’ll keep watch this week as the Moon passes by Jupiter and bright stars – Spica and Antares.

For viewers in Alaska, here’s a unique opportunity… Tonight you’ll have a chance to see the Moon occult Venus! Need a time for your location? Then look no further than this IOTA webpage. For our friends in the UK, you will have the opportunity to watch the Moon occult Beta Virginis tonight. Please check this IOTA webpage for listings of times and cities in your area. Wishing you both clear skies…

For the rest of us, take the time tonight to really study the fully emerged Mare Crisium region telescopically. Look for the small punctuation of craters Pierce toward the northwestern area and Pickard to its south. Can you make out the bright peninsula of Promentorium Agarum on the eastern shore?

Tuesday, August 9 – Tonight after sunset, look again at the crescent Moon and you’ll discover that Jupiter now sits a few scant degrees above its left shoulder. When the stars begin to appear, look for bright Spica about a fist width south of Jupiter.

Tonight we’ll have a look at the smooth sands of Mare Fecunditatis to the lunar south. Binoculars will see the bright, shallow ring of Langrenus on its eastern shore. For telescopic users, this is a great opportunity to pick up two small challenge craters located just northwest of central in Fecunditatis – crater Messier to the east and its companion crater Messier A to the west.

Wednesday, August 10 – For viewers along the eastern sections of both Canada and the US, get your binoculars out and have a look at the Moon right after sunset. Just below the southern cusp you will spot Spica. Watch over the next two hours as the skies fully darken and the distance between them widens as the pair sets.

On the lunar surface, look for the three rings of Theophilus, Cyrillus and Catherina on the edge of Mare Nectaris to the south. A bit further south, you will note a long bright feature known as Rupes Altai, or commonly referred to as the Altai Scarp. This 967 km (600 mile) long feature stretches in an arc from crater Piccolomini through the south shore of Mare Tranquillitatus. While its height doesn’t exceed more than 1.6 – 3.2 km (1 to 2 miles), lunar sunrise highlights it to perfection and you will notice that it is much stronger to the south.

Thursday, August 11 – On this date in 1877, Asaph Hall of the U.S. Naval Observatory was very busy. Tonight would be the first time he would first see Mars’ outer satellite Deimos! Six nights later, he observed Phobos, giving Mars a grand total of two moons. Be sure to watch as Mars begins rising around midnight.

Tonight is the peak of the Perseid meteor shower, but we’ll need to kill about three hours until the Moon sets. If you can’t nap, then look for Venus low on the horizon and notice that Jupiter and Spica are slightly closer together. On the lunar surface, binoculars will see the central Mare Tranquillitatus. For telescope users, on its eastern shore you will see the small bright ring of crater Arago – but don’t stop there. Continue east towards the terminator and watch for a thin, black line that cuts through the foothills. While most rilles are usually within mare areas, the Rimae Ariadaeus is one of the few sufficiently wide enough to be spotted against such a bright background. Running around 233 km (145 miles) long, this is known as a Graben type depression and it only averages around 1.6 – 3.2 km (1 – 2 miles) wide. Although it appears relatively straight, it’s actually a collection of offset segments.

Now let’s sit back and talk about the Perseids while we watch…

The Perseids are undoubtedly the most famous of all meteor showers and never fail to provide an impressive display. Its activity appears all the way back to 36 AD in Chinese history. In 1839, Eduard Heis was the first observer to give an hourly count and discovered their maximum rate was around 160 per hour at that time. He, and other observers, continued their studies in subsequent years to find that number varied.

Giovanni Schiaparelli was the first to relate the orbit of the Perseids to periodic comet Swift-Tuttle (1862 III). The fall rates have both risen and declined over the years as the Perseid stream was studied more deeply and many complex variations discovered. There are actually four individual streams derived from the comet’s 120 year orbital period which peak on slightly different nights, but tonight is our accepted peak.

Meteors from this shower enter Earth’s atmosphere at a speed of 60 km/sec (134,000 miles per hour), from the general direction of the border between the constellations Perseus and Cassiopeia. While they can be seen anywhere in the sky, if you extend their paths backward, all the true members of the stream will point back to this region of the sky. For best success, position yourself so you are generally facing northeast and get comfortable. The radiant will continue to climb higher in the sky as dawn approaches. Around midnight, watch as Mars joins the show and Saturn honors us in the east about an hour before sunrise.

Wishing everyone success!

Friday, August 12 – Practice astronomy in the daytime? Why not! When the Sun reaches its highest point today in the northern hemisphere, you see the Moon rising in the southeast. Watch as the skies darken and you’ll discover red Antares about a handspan to its left.

Tonight let’s return to the lunar surface to pick up another surface “scar”. In the north you will see the rugged terrain of the Montes Alpes. Look for the deep, diagonal gash of the Alpine Valley cutting through them. This artificial looking feature runs around 177 km (110 miles) long and ranges anywhere from 1.6 – 21 km (1 – 13) miles wide. It’s a very curious feature and may very well be a reminder of a glancing blow dealt by a large meteoritic body.

Saturday, August 13 – Tonight Antares is less than a fist width away from the waxing gibbous Moon. On the lunar surface, we can enjoy another strange, thin feature as well. Look toward the lunar south where you will note the prominent rings of craters Ptolemaeus, Alphonsus, Arzachel, Purbach and Walter descending from north to south. Just west of them, you’ll see the emerging Mare Nubium. Between Purbach and Walter you will see the small, bright ring of Thebit with a crater caught on its edge. Look further west and you will see a long, thin, dark feature cutting across the mare. Its name? Rupes Recta – better known as “The Straight Wall”. It is one of the steepest known lunar slopes rising around 366 meters (1200 feet) from the surface at 41 degree angle.

Sunday, August 14 – Look again at the sky tonight as Antares has now moved to the other side of the Moon! For New Zealand and Australia, you will have the chance to see the Moon occult Sigma Scorpii. You can find details on this IOTA webpage. On this same night, viewers in central northern Australia (in the Broome/Darwin area) will also have a chance to see the Moon occult Antares. Please check this IOTA webpage for precise times.

For lunar binocular viewers this evening, two wonderful features are readily awaiting you. Look for the smooth, dark oval of Plato to the north and the emerging grandeur of Copernicus almost central to the terminator. Can you see the wonderful Archimedes between the two – or Eratosthenes hanging onto the tail of the Apennine Mountains?

Until next week, may all your journeys be at light speed…~Tammy Plotner