The Running Chicken Nebula, a cloud of gas and newborn stars that lies around 6500 light-years away from us in the constellation of Centaurus (The Centaur). It’s official name is IC 2944, or the Lambda Centauri Nebula. Credit:ESO
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A brand new image from the Wide Field Imager on the MPG/ESO 2.2-meter telescope reveals the Lambda Centauri Nebula, a cloud of glowing hydrogen and newborn stars in the constellation of Centaurus. The nebula is also known as IC 2944. But it also has one of the most unique nicknames of any other nebula: The Running Chicken Nebula. Can you see a chicken shape in pictures of this red star-forming region? There is some disagreement over exactly which part of the nebula is chicken shaped, with various bird-like features showing up across the picture.
The Running Chicken lies around 6,500 light-years from Earth, and hot newborn stars that formed from clouds of hydrogen gas shine brightly with ultraviolet light. This intense radiation in turn excites the surrounding hydrogen cloud, making it glow a distinctive shade of red.
The other features in this image that stand are the opaque black clumps silhouetted against the red background in part of this image. These are examples of a type of object called Bok globules. They appear dark as they absorb the light from the luminous background. However, observations of these dark clouds using infrared telescopes, which are able to see through the dust that normally blocks visible light, have revealed that stars are forming within many of them.
ESO is having a contest on their Flickr page where you can submit your views of where the chicken outline lies on this, and in participating, you can win some prizes from ESO.
NASA has announced that it will option additional milestones for its Commercial Crew Development Program. Image Credit: SNC
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By all reports – commercial space is thriving. A number of recent announcements show that the burgeoning “private” space industry is thriving. NASA released its plans to obtain transportation services for its astronauts to the International Space Station (ISS) as well as optional milestones for the Commercial Crew Development Round 2 (CCDev2).
“This is a significant step forward in America’s amazing story of space exploration,” said NASA Administrator Charles Bolden. “It’s further evidence we are committed to fully implementing our plan — as laid out in the Authorization Act — to outsource our space station transportation so NASA can focus its energy and resources on deep space exploration.”
To help speed up the process Bolden has stated that NASA will fund some of the original milestones that have already been negotiated as part of some of the Space Act Agreements (SAA) under CCDev2.
NASA’s proposal outlines contracts that would benefit multiple firms that are set to provide the space agency with designs of spacecraft, rockets and other launch services. This contract is worth an estimated $1.61 billion and is currently slated to run from July 2012 through April 2014. NASA has updated Sierra Nevada Corporation’s SAA with four more milestones – that total up to $25.6 million meaning that the contract that this NewSpace firm now has with NASA is worth $105.6 million – if the agency can successfully accomplish all of its milestones.
“All four CCDev2 partners are performing very well and meeting their milestones,” said Phil McAlister, director of NASA’s Commercial Spaceflight Development. “These additional milestones were selected because they sufficiently accelerated the development of commercial crew transportation systems to justify additional NASA investment.”
The Spacecraft Company opened an assembly facility at Mojave Air and Space Port to build Virgin Galactic spaceships. Photo Credit: Mark Greenberg
Meanwhile, out in California, The Spaceship Company (TSC), the joint venture of Sir Richard Branson’s Virgin Galactic and Scaled Composites, announced a milestone of their own with the opening of its Final Assembly, Integration and Test Hangar (FAITH), at the Mojave Air and Space Port. The hangar, which cost an estimated $8 million, supports the final stages of Virgin Galactic’s WhiteKnightTwo and SpaceShipTwo. It is hoped that this new facility will both support further commercial space ventures and create jobs.
The facility is located on taxiway-B and encompasses approximately 68,000-square-feet. It will be used to assemble, prepare and test the vehicles. One of the building’s other roles is that of maintenance hangar.
“We take great pride in the opening of FAITH as an accomplishment for our company, our current and future customers and our industry,” said The Spaceship Company Vice President, Operations Enrico Palermo. “Within this new facility, we will produce the highest quality commercial spaceflight systems.”
With FAITH in place, the required infrastructure is now in place to manufacture a fleet of SpaceShipTwo (SS2) sub-orbital spaceships as well as the WhiteKnightTwo (WK2) carrier aircraft. The facility has been sized to support construction of SS2 and WK2 with room to build two of each of these craft – at the same time.
The other structure that is needed to support SS2 and WK2 operations is a 48,000-square-foot building that is located at the Mojave Air and Space Port that TSC has recently had upgraded. If the sub-orbital space tourism market takes off TSC has optioned rights to expand the facility.
“Despite the current state of the U.S. economy and rising unemployment, this is a strong time of growth for The Spaceship Company,” Palermo said. “We are creating excellent, high-skilled job opportunities for individuals with aerospace, engineering and hands-on space program experience. We want employees who are passionate about developing new and innovative ways of accessing space.”
The SXC has signed a lease for the Lynx (tail number 2) sub-orbital space plane. Image Credit: XCOR
Staying on the topic of sub-orbital space planes, Space Expedition Curaçao (SXC) and XCOR Aerospace, Inc. have announced the completion of a deal that will secure the wet lease of production Lynx tail number two for operation on the Caribbean island of Curaçao.
“Since we signed the initial Memorandum of Understanding (MOU) in October of 2010, XCOR and SXC have worked diligently towards completing the Definitive Agreement,” explained XCOR CEO Jeff Greason. “Now that the ink is dry and the check has cleared we can proceed at full pace to begin operations in Curaçao in 2014.”
Since the first flights of SpaceShipOne high above the Mojave Desert, the commercial space industry has found its legs and has expanded its reach both nationally and internationally. With Space Exploration Technologies (SpaceX) plans to launch its next Falcon 9 rocket and Dragon spacecraft to the International Space Station in November the commercial space field appears to be cementing its beachhead on not only sub-orbital flights – but orbital ones as well.
Princeton and New York University researchers have simulated the effect of a primordial black hole passing through a star. Primordial black holes are among the objects hypothesized to make up dark matter -- the invisible substance thought to constitute much of the universe -- and astronomers could use the researchers' model to finally observe the elusive black holes. This image illustrates the resulting vibration waves as a primordial black hole (white dots) passes through the center of a star. The different colors correspond to the density of the primordial black hole and strength of the vibration. (Image by Tim Sandstrom)
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Well, we’re off to see the Wizard again, my friends. This time it’s to explore the possibilities of primordial black holes colliding with stars and all the implications therein. If this theory is correct, then we should be able to observe the effects of dark matter first hand – proof that it really does exist – and deeper understand the very core of the Universe.
Are primordial black holes blueprints for dark matter? Postdoctoral researchers Shravan Hanasoge of Princeton’s Department of Geosciences and Michael Kesden of NYU’s Center for Cosmology and Particle Physics have utilized computer modeling to visualize a primordial black hole passing through a star. “Stars are transparent to the passage of primordial black holes (PBHs) and serve as seismic detectors for such objects.” says Kesden. “The gravitational field of a PBH squeezes a star and causes it to ring acoustically.”
If primordial black holes do exist, then chances are great that these type of collisions happen within our own galaxy – and frequently. With ever more telescopes and satellites observing the stellar neighborhoods, it only stands to reason that sooner or later we’re going to catch one of these events. But, the most important thing is simply understanding what we’re looking for. The computer model developed by Hanasoge and Kesden can be used with these current solar-observation techniques to offer a more precise method for detecting primordial black holes than existing tools.
“If astronomers were just looking at the Sun, the chances of observing a primordial black hole are not likely, but people are now looking at thousands of stars,” Hanasoge said.”There’s a larger question of what constitutes dark matter, and if a primordial black hole were found it would fit all the parameters — they have mass and force so they directly influence other objects in the Universe, and they don’t interact with light. Identifying one would have profound implications for our understanding of the early Universe and dark matter.”
Sure. We haven’t seen DM, but what we can see are galaxies that are hypothesized to have extended dark-matter halos and to study the effects the gravity has on their materials – like gaseous regions and stellar members. If these new models are correct, primordial black holes should be heavier than existing dark matter and when they collide with a star, should cause a rippling effect.
“If you imagine poking a water balloon and watching the water ripple inside, that’s similar to how a star’s surface appears,” Kesden said. “By looking at how a star’s surface moves, you can figure out what’s going on inside. If a black hole goes through, you can see the surface vibrate.”
Using the Sun as a model, Kesden and Hanasoge calculated the effects a PBH might have and then gave the data to NASA’s Tim Sandstrom. Using the Pleiades supercomputer at the agency’s Ames Research Center in California, the team was then able to create a video simulation of the collisional effect. Below is the clip which shows the vibrations of the Sun’s surface as a primordial black hole — represented by a white trail — passes through its interior.
“It’s been known that as a primordial black hole went by a star, it would have an effect, but this is the first time we have calculations that are numerically precise,” comments Marc Kamionkowski, a professor of physics and astronomy at Johns Hopkins University. “This is a clever idea that takes advantage of observations and measurements already made by solar physics. It’s like someone calling you to say there might be a million dollars under your front doormat. If it turns out to not be true, it cost you nothing to look. In this case, there might be dark matter in the data sets astronomers already have, so why not look?”
Several views of the UARS satellite in orbit, as seen from the ground with a 14" telescope. Credit: Thierry Legault Emmanual Rietsch
The huge Upper Atmosphere Research Satellite (UARS) will be plummeting to Earth in an uncontrolled re-entry this week, but here’s an incredible video from astrophotographer extraordinaire Thierry Legault who shot footage of UARS with his 14-inch telescope. Legault was in Northern France (Dunkerque) last week to attempt to capture views of the satellite, and had success on September 15, 2011 between 04:42:14 and 04:44:02 UTC, just 8-9 days before its atmospheric reentry, when it was at an altitude of only 250 km. The tumbling, uncontrolled nature of the satellite is obvious in this video, and various components are visible, such as the body itself and the solar arrays.
NASA has now refined its prediction for when this bus-sized satellite will fall to Earth. The 20-year-old defunct satellite now has a predicted re-entry Time of about 20:36 UTC on September 23, 2011, plus or minus 20 hours, according the the UARS Reentry Twitter feed. So, heads up!
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This is a day earlier than previously anticipated. Pieces of the 6.5-ton satellite are expected to survive the fiery plunge and hit our planet, but NASA does not know exactly where. There was word today that increased activity from the Sun has hastened the decay of the satellite’s orbit.
Legault said his images show the satellite at a 316 km distance to the observer. The angular speed at culmination: 1.36°/s. The speed of the sequence is accelerated two times with regard to real time (20 fps vs 10 fps). The satellite is tumbling, perhaps because of a collision with satellite debris a few years ago.
Here is the equipment Legault used: Celestron EdgeHD 14” Schmidt-Cassegrain telescope (at a focal length of 8500mm) on automatic tracking system, as described on this page. Camera: Lumenera Skynyx L2-2.
Thanks to Legault for sharing his video and images with Universe Today! See more info at Legault’s website.
Map of the UARS orbital path. Credit: @UARS_Reentry Twitter feed.
NASA says there are about 26 components that are big enough to survive and make it down to Earth, the largest weighing more than 150 kg (330 pounds.)
What are you chances of getting hit by debris? Nick Johnson, chief scientist with NASA’s Orbital Debris Program, said that numerically, it comes out to a chance of 1 in 3,200 that any one person anywhere in the world might be struck by a piece of debris. That might sound high, but if you factor in that there are 7 billion people on Earth and that a large part of Earth is covered by water, the liklihood is actually very small. The chance that any one person on Earth getting hit by debris has been estimated at about 1 in 21 trillion.
We’ll provide more updates on the UARS story. For those who would like to catch a last glimpse of UARS streaking across the night sky for yourself should check Heaven’s Above or SpaceWeather’s Satellite Tracker for flyby times in your area.
Here at Universe Today, we’ve been providing plenty of coverage on the recent supernova in spiral galaxy M101 (AKA Pinwheel Galaxy). Readers have uploaded their images to our Flickr page and have been asking about the event, weeks after it was detected.
While the supernova has been dimming since its peak brightness, most supernova events brighten quickly, but fade slowly. This supernova is by no means visible with the naked eye, but here’s what you need to know to catch a glimpse of the brightest supernova in the past few decades.
First a short primer on M101: Nicknamed the “Pinwheel Galaxy” for its resemblance to the toy, M101’s distinct spiral arms can be imaged with modest amateur astronomy equipment. M101 is about six megaparsecs ( 1 parsec is just over three and one-quarter light years ) away from our solar system, which is over six times more distant than our closest neighbor, the Andromeda Galaxy. M101 is a galaxy that is much larger than our own galaxy – nearly double the size of the Milky Way.
What made M101 newsworthy as of late was the Type Ia supernova discovered inside the galaxy. Discovered nearly a month ago on August 24th, SN 2011fe (initial designation PTF 11kly) started off at around 17th magnitude and recently peaked around magnitude 10 (magnitude 6-7 is limit of “naked-eye” visibility with dark skies).
Scientists and amateur astronomers alike have scrambled to gather data on SN 2011fe. Some observers have even looked through data collected in late August only to see they captured the supernova without knowing it!
Supernova PTF11kly / SN 2011fe in Messier 101. Credit: Joe Brimacombe
By mid-September, though, SN 2011fe has become too faint for casual observers to see, but experienced amateur astronomers can still see it with telescopes. If you don’t have a good-sized “amateur” telescope, you might consider contacting a local astronomy club to see if they are having a “star party” or observing night in your area. To find an astronomy club, check out NASA’s Night Sky Network.
Viewing M101 and SN 2011fe isn’t terribly challenging, so long as you have a decent view to the North. You can find M101 by using the Big Dipper asterism (Ursa Major for the constellation purists). Look for the last two stars of the Big Dipper’s handle (Mizar and Alkaid). Above the midpoint between the two stars is M101. For those with motorized telescopes, start at Mizar, slew a little to the east and up a little. People who are lucky enough to have a computerized, “Go-To” scope can enter the RA and Dec coordinates of 14:03:05.81 , +54:16:25.4.
This week you’ll want to try viewing M101 in late evenings, otherwise you may find it too close to the horizon and washed out by the waning gibbous Moon. To your eyes, M101 will appear as a fuzzy “smudge” in the eyepiece. If you are at a very dark site and use averted (looking slightly to the side of the object) vision you might see some detail with a 12″ or larger telescope. You can certainly view M101 with a telescope as small as 6″, but you really do want to view M101 with as big of a telescope as possible. Don’t use higher power eyepieces to try and make up for a small telescope. Many galaxies, including M101 are best viewed with mid-to-low power eyepieces.
Below is an image generated by Stellarium. In the image are a few constellations and some guide stars you can use to guide your eyes and telescope to M101.
Clear skies and good luck!
Location of M101 at 9 PM ( 33 Degrees N. ) Image generated with Stellarium
Once upon a time, about 65 million years ago, scientists hypothesize a sizable asteroid crashed into Earth and contributed to the extinction of the dinosaurs. The evidence is a 150-kilometer-wide crater located just off the Yucatan peninsula and legend has it the 10-kilometer-wide asteroid was a fragment of a larger parent – Baptistina. Now, thanks to observations by NASA’s Wide-field Infrared Survey Explorer (WISE), we just might have to re-think that theory.
While there’s almost absolutely no doubt an asteroid crash was responsible for a cataclysmic climate change, science has never been particularly sure of what asteroid caused it. A visible-light study done by terrestrial telescopes in 2007 pointed a finger at a huge asteroid known as Baptistina. The conjecture was that about 160 million years ago, it collided with another main belt asteroid and sent pieces flying. Even though it was plausible, the theory was quickly challenged and now infra-red evidence from WISE may finally lay this family of asteroids to rest.
“As a result of the WISE science team’s investigation, the demise of the dinosaurs remains in the cold case files,” said Lindley Johnson, program executive for the Near Earth Object (NEO) Observation Program at NASA Headquarters in Washington. “The original calculations with visible light estimated the size and reflectivity of the Baptistina family members, leading to estimates of their age, but we now know those estimates were off. With infrared light, WISE was able to get a more accurate estimate, which throws the timing of the Baptistina theory into question.”
For over a year, WISE took an infra-red survey of the entire sky and asteroid-hunting portion of the mission, called NEOWISE, cataloged 157,000 members – discovering an additional 33,000 new ones. By utilizing the more accurate infra-red data, the team examined 1,056 members of the Baptistina family and discovered its break-up was closer to 80 million years ago – less than half the time previously suggested. By better knowing their size and reflectivity, researchers are able to calculate how long it would take for Baptistina members to reach their current position. The results show that in order for this particular asteroid to have caused an extinction level event, that it would have had to have impacted Earth much sooner… like about 15 million years.
“This doesn’t give the remnants from the collision very much time to move into a resonance spot, and get flung down to Earth 65 million years ago,” said Amy Mainzer, a study co-author and the principal investigator of NEOWISE at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena. Calif. “This process is thought to normally take many tens of millions of years.”
Like bouncing a super ball off the walls, resonance spots can jettison asteroids out of the main belt. This means a dinosaur-killing Baptistina event isn’t likely, but other asteroid families in NEOWISE study show similar reflective properties and one day we may be able to locate a responsible party.
“We are working on creating an asteroid family tree of sorts,” said Joseph Masiero, the lead author of the study. “We are starting to refine our picture of how the asteroids in the main belt smashed together and mixed up.”
The VLT Survey Telescope (VST) is the latest telescope to be added to ESO’s Paranal Observatory in the Atacama Desert of northern Chile. Credit: ESO/G. Lombardi
[/caption]We get this question the time. People want to get into astronomy, and they want to get their first telescope. So, to all you experienced astronomers reading Universe Today, what do you suggest people consider for their first starting telescope? We’ve heard lots of horror stories about bad quality department store telescopes, so where should people go? How much should they expect to spend? Who are some good telescope manufacturers? What should people avoid?
My first answer is always to suggest that people use a planisphere and their own eyes in the beginning, learning the constellations. Then graduating to binoculars if they’re still enjoying the hobby before even considering a telescope purchase. What’s your opinion?
Apollo LM orbiting the sun, Credit: Adrian West http://twitter.com/virtualastro
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Where is the Apollo 10 Lunar lander module? It’s somewhere out there — orbiting the Sun — and there’s a new initiative to try and find it!
The Apollo 10 mission launched on May 18, 1968 and was a manned “dry run” for its successor Apollo 11, testing all of the procedures and components of a Moon landing without actually landing on the Moon itself.
After carrying out a successful lunar orbit and docking procedure, the Lunar Module (called “Snoopy”) was jettisoned and sent into an orbit around the Sun.
After 42 years, it’s believed to still be in a heliocentric orbit and a team of UK and international astronomers working with schools are going to try and find it.
The idea is the brainchild of British amateur astronomer Nick Howes who helped coordinate a very successful asteroid and comet project with schools and Faulkes Telescope during this past summer.
After consulting with people from NASA’s Jet Propulsion Laboratory and other orbital dynamics experts, the Howes has assembled a team of facilities and experts, including the Faulkes Telescope, Space Exploration Engineering Corp, astronomers from the Remanzacco Observatory in Italy and schools across the UK.
They know they have a massive undertaking ahead of them to find Snoopy.
“The key problem which we are taking on is a lack of solid orbital data since 1969,” Howes told Universe Today. “We’ve enlisted the help of the Space Exploration Engineering Corp who have calculated orbits for Apollo 10 and working closely with people who were on the Apollo mission team in the era will help us identify search coordinate regions.”
“We’re expecting a search arc anywhere up to 135 million kilometres in size which is a huge amount of space to look at, ” Howes continued. “We’re aware of the scale and magnitude of this challenge but to have the twin Faulkes scopes assist the hunt, along with schools, plus the fact that we’ll doubtless turn up many new finds such as comets and asteroids makes this a great science project too. We’re also encouraging anyone to have a go as we’ll be posting the coordinates on to the Faulkes Telescope website starting in a few days”
While the challenge ahead of Howes and the team is enormous, and the chances of the team finding Snoopy are very small, the team are enthusing thousands of people with their own “Apollo Mission” – the mission to find the missing Apollo Lunar module.
An artistic image of the explosion of a star leading to a gamma-ray burst. (Source: FUW/Tentaris/Maciej Fro?ow)
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Dark energy… We’re still not exactly sure of what it is or where it comes from. Is it possible this mysterious force is what’s driving the expansion of the Universe? A group of astronomers from the universities in Warsaw and Naples, headed by Dr. Ester Piedipalumbo, are taking a closer look at a way to measure this energetic enigma and they’re doing it with one of the most intense sources they can find – gamma-ray bursts.
“We are able to determine the distance of an explosion on the basis of the properties of the radiation emitted during gamma-ray bursts. Given that some of these explosions are related to the most remote objects in space that we know about, we are able, for the first time, to assess the speed of space-time expansion even in the relatively early periods after the Big Bang,” says Prof. Marek Demianski (FUW).
What spawned this new method? In 1998, astronomers were measuring the energy given off by Type Ia supernovae events and realized the expelled forces were consistent. Much like the standard candle model, this release could be used to determine cosmic distances. But there was just one caveat… The more remote the event, the weaker the signature.
While these faint events weren’t lighting up the night, they were lighting up the way science thought about things. Perhaps these Type Ia supernovae were farther away than surmised… and if this were true, perhaps instead of slowing down the expansion of the Universe, maybe it was accelerating! In order to set the Universal model to rights, a new form of mass-energy needed to be introduced – dark energy – and it needed to be twenty times more than what we could perceive. “Overnight, dark energy became, quite literally, the greatest mystery of the Universe,” says Prof. Demianski. In a model put forward by Einstein it’s a property of the cosmological constant – and another model suggests accelerated expansion is caused by some unknown scalar field. “In other words, it is either-or: either space-time expands by itself or is expanded by a scalar physical field inside it,” says Prof. Demianski.
So what’s the point behind the studies? If it is possible to use a gamma-ray burst as a type of standard candle, then astronomers can better assess the density of dark energy, allowing them to further refine models. If it stays monophonic, it belongs to the cosmological constant and is a property of space-time. However, if the acceleration of the Universe is the property of a scalar field, the density of dark energy would differ. “This used to be a problem. In order to assess the changes in the density of dark energy immediately after the Big Bang, one needs to know how to measure the distance to very remote objects. So remote that even Type Ia supernovae connected to them are too faint to be observed,” says Demianski.
Now the real research begins. Gamma-ray bursts needed to have their energy levels measured and to do that accurately meant looking at previous studies which contained verified sources of distance, such as Type Ia supernovae. “We focused on those instances. We knew the distance to the galaxy and we also knew how much energy of the burst reached the Earth. This allowed us to calibrate the burst, that is to say, to calculate the total energy of the explosion,” explains Prof. Demianski. Then the next step was to find statistical dependencies between various properties of the radiation emitted during a gamma-ray burst and the total energy of the explosion. Such relations were discovered. “We cannot provide a physical explanation of why certain properties of gamma-ray bursts are correlated,” points out Prof. Demianski. “But we can say that if registered radiation has such and such properties, then the burst had such and such energy. This allows us to use bursts as standard candles, to measure distances.”
Dr. Ester Piedipalumbo and a team of researchers from the universities in Warsaw and Naples then took up the gauntlet. Despite this fascinating new concept, the reality is that distant gamma-ray bursts are unusual. Even with 95 candidates listed in the Amanti catalogue, there simply wasn’t enough information to pinpoint dark energy. “It is quite a disappointment. But what is important is the fact that we have in our hands a tool for verifying hypotheses about the structure of the Universe. All we need to do now is wait for the next cosmic fireworks,” concludes Prof. Demianski.
A daytime Moon over New Zealand in August 2010. Credit: NASA/Phil Davis
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Did you know that you can see the Moon during the day?
Many people only notice our Moon at night, when there is considerably more contrast between the Moon and the night sky. Being the second brightest object in the sky (after the Sun, of course) and with Venus visible during the day to trained eyes, it’s no real surprise that the Moon is visible during the day.
Why then, do so many people act surprised when they notice the Moon during the day? What makes it possible for the Moon to be visible during the day?
Understanding how and when you can spot the Moon is a matter of knowing the different lunar phases, specifically the relationship between the Sun, Earth and the Moon during each phase. The image below shows the simple geometry responsible for each of the Moon’s distinct phases.
In the diagram it’s pretty easy to see that when Earth is between the Sun and the Moon, we see a full moon. When the Moon is between Earth and the Sun, we see a new Moon. The other phases are simply transitions from new to full and from full back to new.
Schedule of Moon Phases. Times shown indicate when the moon is overhead.
Based on the orbital geometry of the Moon, there will certainly be times where the Sun will partially illuminate the Moon, during the day and at night. What makes the lunar cycle even more interesting is that the moon rises about an hour later each day, and yet invariably, a full moon rises near dusk and sets near sunrise. The reverse is true in that a new moon rises near sunrise and sets near dusk.
Looking at the above diagram though, a question comes to mind…
Why don’t we have a lunar eclipse during each full moon, or a solar eclipse each new moon?
I’ll explain the conditions needed for a solar or lunar eclipse in an upcoming article.
In the meantime enjoy the transition from waning gibbous to waning crescent over the next week and get your telescopes out during the weekend of the 25th. The Moon will almost be at its new phase.
If you’d like to learn more about moon phases and when the moon will be visible in your area, the US Naval observatory has a great calculator at: http://aa.usno.navy.mil/data/docs/RS_OneYear.php
