Posted on by Nancy Graziano

Returning the “Silent Sentinel” to Active Duty

Situated on the south shore of New Jersey’s Shark River lies 37 acres of land known as Camp Evans. On April 1, 2015, I was privileged to attend the dedication ceremony celebrating Camp Evans’ becoming one of only 2532 locations in the United States designated as a National Historic Landmark.

Plaque Commemorating the Designation of Camp Evans as a National Historic Landmark. April 2, 2015. [photo: Robert Raia Photography]
Plaque Commemorating the Designation of Camp Evans as a National Historic Landmark. April 1, 2015. [photo: Robert Raia Photography]
Camp Evans, originally known as the Belmar Receiving Station, is rich in history:

  • In 1912, Gugliemlo Marconi and his company, the American Marconi Company, constructed the Belmar Receiving Station which became part of the wireless girdle of the earth.
  • In 1917, the site was acquired as part of the Navy’s World War I “Trans-Atlantic Communication System.”
  • In 1941, the Army Signal Corps purchased the property to construct a top-secret research facility, and it was renamed Evans Signal Laboratory which later became Camp Evans Signal Laboratory.
  • Following a visit in late October, 1953, Senator Joseph McCarthy described Camp Evans as a “house of spies.” Following an investigation that spanned 1953-1954, not one single employee was prosecuted.

But perhaps Camp Evans’ most interesting – and surprising – place in history begins with a small, informal research project taking place on a parcel of land in the Camp’s northeast corner. The ramifications of this project would ultimately give birth the to Space Age, lead to the development of the US Space Program, and start the Cold War.

Following the end of WWII, American scientists at Camp Evans continued their investigation into whether the earth’s ionosphere could be penetrated using radio waves – a feat that had been studied prior to the end of the War but had long been believed impossible. Project Diana, led by Lt. Col. John H. DeWitt, Jr., aimed to prove that it could indeed be penetrated. A group of radar scientists awaiting their discharge from the Army modified a radar antenna – including significantly boosting its output power – and placed it in the northeast corner of Camp Evans.

RADAR Dish at Camp Evans Circa 1946
Location of the Radar Antenna on the Northeast Corner of Camp Evans Circa 1946. [photo: InfoAge website]

On the morning of January 10, 1946, with the dish pointed at the rising moon, a series of radar signals was broadcast. Exactly 2.5 seconds after each signal’s broadcast, its corresponding echo was detected. This was significant because 2.5 seconds is precisely the time required for light to travel the round trip distance between the earth and the moon. Project Diana – and her scientists – had successfully demonstrated that the ionosphere was, in fact, penetrable, and communication beyond our planet was possible. And thus was born the Space Age – as well as the field of Radar Astronomy.

SCR-271 Bedspring RADAR Antenna Pointing at the Moon [photo: David Mofenson; InfoAge website]
SCR-271 Bedspring RADAR Antenna Pointing at the Moon [photo: David Mofenson; InfoAge website]
By mid-1958 the United States had launched the Television InfraRed Observation Satellite (TIROS) program designed to study the viability of using satellite imagery and observations as a means of studying the Earth and improving weather forecasting. As part of this effort, the original “Moonbounce” antenna was replaced with a 60-foot parabolic radio antenna dish which would serve as the project’s downlink Ground Communication Station.

60-Meter Parabolic Dish Being Constructed on Project Diana Site [photo: Frank Vosk; InfoAge website]
60-Meter Parabolic Dish Being Constructed on Project Diana Site [photo: Frank Vosk; InfoAge website]
On April 1, 1960, NASA successfully launched its TIROS I satellite and the “Silent Sentinel Radio Dish” at Camp Evans began receiving its data being sent down to earth.

TIROS I Satellite
TIROS I Satellite [photo: NASA; National Space Science Data Center]
The resulting images were so astonishing and groundbreaking that the first photos received from TIROS I were immediately printed and flown to Washington where they were presented to President Eisenhower by NASA Administrator T. Keith Glennan.

President Eisenhower and NASA Administrator Glennan Viewing the First Satellite Images from TIROS I. [photo: wikimedia commons]
President Eisenhower and NASA Administrator Glennan Viewing the First Satellite Images from TIROS I. [photo: wikimedia commons]
The TIROS program would go on to be instrumental in meteorological applications not only because it provided the first accurate weather forecasts and hurricane tracking based on satellite information, but also because it began providing continuous coverage of the earth’s weather in 1962, and ultimately lead to the development of more sophisticated observational satellites. [1]

In addition to serving as the downlink Ground Communications Center for the TIROS I and TIROS II satellites, this same dish has also tracked:

Sadly, by the mid-1970s, the technology within the TIROS dish (officially named the TLM-18 Space Telemetry Antenna) had become obsolete, and it was retired. Camp Evans was decommissioned and closed in 1993 and its land was transferred to the National Park Service. But in 2012, Camp Evans was designated a National Historic Landmark, and thus began a new, revitalized era for this immensely significant site. In addition to the TIROS Dish and the InfoAge Science History Learning Center and Museum, Camp Evans is also home to:

  • The Military History Museum;
  • The Radio Technology Museum;
  • The National Broadcasters’ Hall of Fame.
Apollo Guidance Computer
The Apollo Guidance Computer, Just One of the Many Historical Exhibits on Display at the InfoAge Science History Learning Center and Museum at Historic Camp Evans [photo: Robert Raia Photography]

DISH RESTORATION

In 2001, InfoAge stepped in and began preserving and restoring the mechanical systems of the TIROS dish. In 2006, a donation from Harris Corporation allowed the dish to be completely repainted and preserved.

Norman Jarosik, Senior Research Physicist at Princeton University and Daniel Marlow, PhD. and Evans Crawford 1911 Professor of Physics at Princeton, as well as countless volunteers from the University, InfoAge, Wall Township (NJ), and the Ocean-Monmouth Amateur Radio Club, Inc. (OMARC) have provided the engineering/scientific knowledge and sweat-equity required to refurbish and update the inoperative radio dish. The original vacuum-tube technology has been replaced with smaller electronic counterparts. Rusty equipment has been replaced. Seized/inoperative motors have been reconditioned and rebuilt. And system-level software controls have been added. The TIROS dish has been transformed into a truly modern, state-of-the-art Radio Astronomy Satellite Dish and Control Center.

The TIROS Dish as it Appears Today [photo: Nancy J. Graziano]
The TIROS Dish as it Appears Today [photo: Nancy J. Graziano]
On January 19, 2015, scientists from Princeton University pointed the dish skyward toward the center of our galaxy and detected a clear peak at 1420.4 MHz, the well-known 21 cm emission line originating from the deepest recesses of the Milky Way – the dish was working!

The Control Console Today. [photo: Nancy J. Graziano]
The Control Console Today. [photo: Nancy J. Graziano]

FUTURE PLANS

After almost 15 years of restoration and nearly 40 years since it last listened to the sky, the TIROS dish is once again operational, is detecting radio signals from the universe, and is well on its way to be used for science education.

Work continues on renovating Building 9162, the original TIROS Control Building, to convert it into the InfoAge Visitor Center. Plans include a NASA-style control room with theater seating for 20-30 students, a full-scale model of the original TIROS I satellite, and other exhibits dedicated to the history of Project Diana, the TIROS program, and the scientific impact these projects have had on our daily lives.

Visitor Center Floorplan [credit: InfoAge]
Artist’s Conception: Visitor Center Floorplan [credit: InfoAge]
Future activities being planned using the dish include a Moonbounce experiment, communicating with NOAA weather satellites, performing real-time satellite imaging, viewing the Milky Way in the radio spectrum, and tracking deep space pulsars.

If you are interested in visiting the InfoAge Science History Learning Center and Museum at Historic Camp Evans, they are open to the public on Wednesdays, Saturdays, and Sundays, from 1-5pm.

To learn more about Camp Evans, Project Diana, the TIROS Satellite project, and InfoAge, tune into this week’s Weekly Space Hangout. This week’s special guest is Stephen Fowler, the Creative Director at InfoAge. He will be chatting with Fraser about the history and plans for Camp Evans and the TIROS dish.

Still want to learn more? Click on any of the links provided in this article, or visit the following sites:

Posted on by Fraser Cain

Weekly Space Hangout – May 8, 2015: Emily Rice & Brian Levine from Astronomy on Tap

Host: Fraser Cain (@fcain)
Special Guest: Emily Rice & Brian Levine from Astronomy on Tap

Guests:
Jolene Creighton (@jolene723 / fromquarkstoquasars.com)
Charles Black (@charlesblack / sen.com/charles-black)
Brian Koberlein (@briankoberlein)
Dave Dickinson (@astroguyz / www.astroguyz.com)
Continue reading “Weekly Space Hangout – May 8, 2015: Emily Rice & Brian Levine from Astronomy on Tap”

Posted on by Fraser Cain

What is the Moon’s Real Name?

What is the Moon’s Real Name?

We call it the Moon, but… what’s its real name? You know, the name that scientists call the Moon.

As of 2015, there are 146 official moons in the Solar System, and then another 27 provisional moons, who are still waiting on the status of their application. All official moons have names after gods or Shakespeare characters. Names like Callisto, Titan, or Prometheus. But there’s one moon in the Solar System with a super boring name… the one you’re most familiar with: Moon.

But come on, that’s such a boring name. Clearly that’s just its common name. So what’s the Moon’s real name? Its scientific name. The neato cool name. Like Krelon, Krona, Avron or Mua’Dib.

Are you ready for this? The answer is: The Moon. Here’s some hand-waving and excuse making. Really, this is our own damn fault. Until Galileo first turned his telescope to the skies in 1610, and realized that Jupiter had tiny spots of light orbiting around it, astronomers had no idea other planets had moons.

Humans have been around for a few hundred thousand years, and the Moon was a familiar object in the sky. We’ve only had evidence of other moons for a little over 400 years. We didn’t collectively understand the Earth was a planet until Copernicus developed the heliocentric model of the Solar System.

We still have a little trouble with that, even though we’re firing a probe directly at the Sun. We didn’t give into the idea that the Sun was a star until recently. Giordano Bruno proposed the idea in 1590 and we burned him at the stake for suggesting it. Seriously, I can’t stare at this any longer. Yes, we’re awful. I’m going to talk about “the Moon” again.

Scientists classify the Moon as a natural satellite. Somehow this helps distinguish it from the artificial satellites we’ve been launching for the last 60 years.

High resolution photo map of the moon's far side imaged by NASA's Lunar Reconnaissance Orbiter. Mare Moscoviense lies at upper left and Tsiolkovsky at lower left. Click for a hi res image. Credit: NASA
High resolution photo map of the moon’s far side imaged by NASA’s Lunar Reconnaissance Orbiter. Credit: NASA

What about terms like “Luna”? That’s Latin for Moon. It’s not an official title or scientific term, but ooh, fancy. Latin.

If you want to make sure people know you’re talking about “The Moon” and not “a moon”, it’s all about capitalization. Put a capital “M” in front of “oon” and you’re good to go.

The name of our solar system? It’s the Solar System (again, capitalized). Our galaxy? The Galaxy with a capital G. The universe? Capital U Universe.

What about the Sun? Isn’t it “sol”? That’s just the Latin word for “sun”. Helios? Greek God version of the Sun.

If we ever discover that we’re really living in a multiverse, we’ll need to give those other universes names. And people will wonder what the actual official title is for the Universe. I’ll make another video when that happens, I promise.

The official advice from the International Astronomical Union, who are the people you’re still mad at about Pluto, is that the capitalization is what makes the definition.

Supermoon through the clouds on September 9, 2014. Credit and copyright: scul-001 on Flickr.
Supermoon through the clouds on September 9, 2014. Credit and copyright: scul-001 on Flickr.

Not everyone in the world adheres to the capitalization so carefully, which can tend to some confusion. Are we talking about the sun or the Sun? As someone who writes space articles, let me assure you, messing this up will light up the comments section with “Which is better Deep Space 9 vs. Voyager” level of shrill all caps screaming.

Calling it “the Moon” is kind of boring, but that’s only because scientific discovery has pushed our understanding of the Universe so far out. It’s amazing to think that we’ve discovered so many other moons in the Solar System, and soon, we’ll find them around other stars.

So, for now it’s The Universe. When we find others, this one will still be THE Capital-U Universe and the new ones will be Nimoy and Sagan and Clarke.

Why don’t we give the Moon a new name. Something with a little more razzle-dazzle. Make your suggestions in the comments below. Alternately, suggest a fancy Latin name of “Guide to Space”, I’ve got dibs on “Aether Libris”.

Thanks for watching! Never miss an episode by clicking subscribe.

Posted on by Bob King

Lunar ‘Fountain of Youth’ Challenge / Mercury Returns with Gusto

A day-old Moon floats over the Spirit Mountain ski hill in Duluth, Minn. this past January. Credit: Bob King

16th century Spanish explorer Juan Ponce de León looked and looked but never did find the Fountain of Youth, a spring rumored to restore one’s youth if you bathed or drank from its waters.  If he had, I might have interviewed him for this story.

Sunday night, another symbol of youth beckons skywatchers the world over. A fresh-faced, day-young crescent Moon will hang in the western sky in the company of the planets Mars and Mercury. While I can’t promise a wrinkle-free life, sighting it may send a tingle down your spine reminding you of why you fell in love with astronomy in the first place. 

Look low in the west-northwest sky Sunday evening April 19 to spot the day-old crescent Moon alongside Mars and returning Mercury. Source: Stellarium
Look low in the west-northwest sky Sunday evening April 19 to spot the day-old crescent Moon alongside Mars and returning Mercury. Brilliant Venus will help you get oriented. This map shows the sky around 40 minutes after sunset but you can start as early as 30 minutes especially if you’re using binoculars. Source: Stellarium

The Moon reaches New Moon phase on Saturday, April 18 during the early afternoon for North and South America. By sunset Sunday, the fragile crescent will be about 29 hours old as seen from the East Coast, 30 for the Midwest, 31 for the mountain states and 32 hours for the West Coast. Depending on where you live, the Moon will hover some 5-7° (three fingers held at arm’s length) above the northwestern horizon 40 minutes after sunset. To make sure you see it, find a location with a wide-open view to the west-northwest.

Earthshine gets easier to see once the Moon moves a little further from the Sun and into a dark sky. Our planet provides enough light to spot some of the larger craters. Credit: Bob King
Earthshine gets easier to see as the Moon moves further from the Sun and the crescent fills out a bit. Our planet provides enough light to spot some of the larger craters. Credit: Bob King

While the crescent is illuminated by direct sunlight, you’ll also see the full outline of the Moon thanks to earthshine. Sunlight reflected off Earth’s globe faintly illuminates the portion of the Moon not lit by the Sun. Because it’s twice-reflected, the light looks more like twilight. Ghostly. Binoculars will help you see it best.

Now that you’ve found the dainty crescent, slide your eyes (or binoculars) to the right. That pinpoint of light just a few degrees away is Mars, a planet that’s lingered in the evening sky longer than you’ve promised to clean out the garage. The Red Planet shone brightly at opposition last April but has since faded and will soon be in conjunction with the Sun. Look for it to return bigger and brighter next May when it’s once again at opposition.

Diagram showing Mercury's position and approximate altitude above the horizon during the current apparition. Also shown are the planet's phases, which are visible in a telescope. Credit: Stellarium, Bob King
Diagram showing Mercury’s position and approximate altitude above the horizon during the current apparition. Also shown are the planet’s changing phases, which are visible in a telescope. Credit: Stellarium, Bob King

To complete the challenge, you’ll have to look even lower in the west to spot Mercury. Although brighter than Vega, it’s only 3° high 40 minutes after sunset Sunday. Its low altitude makes it Mercury is only just returning to the evening sky in what will become its best appearance at dusk for northern hemisphere skywatchers in 2015.

As an inner planet, Mercury goes through phases just like Venus and the Moon. We see it as everything from a crescent to a "full moon" as it angle to the Sun changes during its 88-day orbit. Credit: ESO
As an inner planet, Mercury goes through phases just like Venus and the Moon. We see it morph from crescent to “full moon” as its angle to the Sun changes during its revolution of the Sun. Credit: ESO

Right now, because of altitude, the planet’s a test of your sky and observing chops, but let the Moon be your guide on Sunday and you might be surprised. In the next couple weeks, Mercury vaults from the horizon, becoming easier and easier to see.  Greatest elongation east of the Sun occurs on the evening of May 6. Although the planet will be highest at dusk on that date, it will have faded from magnitude -0.5 to +1.2. By the time it leaves the scene in late May, it will become very tricky to spot at magnitude +3.5.

Mercury’s a bit different from Venus, which is brighter in its crescent phase and faintest at “full”. Mercury’s considerably smaller than Venus and farther from the Earth, causing it to appear brightest around full phase and faintest when a crescent, even though both planets are largest and closest to us when seen as crescents.

Not to be outdone by Venus earlier this month, Mercury passes a few degrees south of the Pleiades star cluster on April 29. The map shows the sky facing northwest about 50 minutes after sunset. Source: Stellarium
Not to be outdone by the Venus-Pleiades conjunction earlier this month, Mercury passes a few degrees south of the star cluster on April 29. The map shows the sky facing northwest about 50 minutes after sunset. Source: Stellarium

Venus makes up for its dwindling girth by its size and close proximity to Earth. It also doesn’t hurt that it’s covered in highly reflective clouds. Venus reflects about 70% of the light it receives from the Sun; Mercury’s a dark world and gives back just 7%. That’s dingier than the asphalt-toned Moon!

Good luck in your mercurial quest. We’d love to hear your personal stories of the hunt — just click on Comments.

Posted on by Bob King

Don’t Blink! April 4th Lunar Eclipse Shortest of the Century

The phases of a total lunar eclipse. Credit: Keith Burns / NASA

Get ready for one awesome total lunar eclipse early Saturday morning April 4th. For the third time in less than a year, the Moon dips into Earth’s shadow, its dazzling white globe turning sunset red right before your eyes.  All eclipses are not-to-miss events, but Saturday’s totality will be the shortest in a century. Brief but beautiful – just like life. Read on to find out how to make the most of it.

Four total lunars in succession is called a tetrad. During the 21st century there are nine sets of tetrads. Credit: NASA
Four total lunar eclipses in succession with no partials in between is called a tetrad. The April 4th eclipse is part of a tetrad that started last April and will wrap up on September 28. During the 21st century there will be eight sets of tetrads. Credit: NASA

Lunar eclipses don’t usually happen in any particular order. A partial eclipse is followed by a total is followed by a penumbral and so on. Instead, we’re in the middle of a tetrad, four total eclipses in a row with no partials in between. The final one happens on September 28.  Even more remarkable, part or all of them are visible from the U.S. Tetrads will be fairly common in the 21st century with eight in all. We’re lucky — between 1600 and 1900 there were none! For an excellent primer on the topic check out fellow Universe Today writer David Dickinson’s “The Science Behind the Blood Moon Tetrad“.

The Moon moves out of total eclipse and into partial phases during the second of the four tetrad eclipses on October 8, 2015. Credit: Bob King
The partially eclipsed Moon on October 8, 2015.  For skywatchers across the eastern half of North America, this is about how the Moon will appear shortly before it sets. Those living further west will see totality. Credit: Bob King

Lots of people have taken to calling the tetrad eclipses Blood Moons, referring to the coppery color of lunar disk when steeped in Earth’s shadow and the timing of both April events on the Jewish Passover. Me? I prefer Bacon-and-Eggs Moon. For many of us, the eclipse runs right up till sunrise with the Moon setting in bright twilight around 6:30 a.m. What better time to enjoy a celebratory breakfast with friends after packing away your gear?

Map showing where the April 4 lunar eclipse will be penumbral, partial and total. Inset shows a world map. Credit: Larry Koehn / shadowandsubstance.com
Map showing where the April 4 lunar eclipse will be penumbral, partial and total. World map shown in inset. Credit: Larry Koehn / shadowandsubstance.com Inset: Fred Espenak

But seriously, Saturday morning’s eclipse will prove challenging for some. While observers in far western North America, Hawaii, Japan, New Zealand and Australia will witness the entire event, those in the mountain states will see the Moon set while still in totality. Meanwhile, skywatchers in the Midwest and points East will see only the partial phases in a brightening dawn sky. Here are the key times of eclipse events by time zone:

A total lunar eclipse occurs only during Full Moons when the Sun, Earth and Moon form a straight line. The Moon slips directly behind Earth into its shadow. The outer part of the shadow or penumbra is a mix of sunlight and shadow. The inner cone, called the umbra, the Sun is completely blocked from view. However, light refracted by Earth's atmosphere is bent into the umbra where it colors the eclipsed Moon red.
A total lunar eclipse occurs only during full moon phase when the Sun, Earth and Moon lie in a straight line. The Moon slips directly behind Earth into its shadow. The outer part of the shadow or penumbra is a mix of sunlight and shadow and only partially dark. From  the inner shadow, called the umbra, the Sun is completely blocked from view. A small amount of sunlight refracted or bent by Earth’s atmosphere into the umbra, spills into the shadow, coloring the eclipsed Moon red.

Eclipse Events                                     EDT              CDT              MDT             PDT

Penumbra eclipse begins 5:01 a.m. 4:01 a.m. 3:01 a.m. 2:01 a.m.
Partial eclipse begins 6:16 a.m. 5:16 a.m. 4:16 a.m. 3:16 a.m.
Total eclipse begins ——– ——– 5:58 a.m. 4:58 a.m.
Greatest eclipse ——– ——– 6:00 a.m. 5:00 a.m.
Total eclipse ends ——– ——– 6:03 a.m. 5:03 a.m.
Partial eclipse ends ——— ——– ——– 6:45 a.m.
Penumbra eclipse ends ——— ——— ——– ——–

* During the penumbral phase, shading won’t be obvious until ~30 minutes before partial eclipse.

Partial eclipse, when the Moon first enters Earth's dark, inner shadow called the umbra, begins at 5:16 a.m. CDT near the start of morning twilight. Totality begins at 6:58 a.m. with the Moon already set for the eastern half of the country. Credit: Fred Espenak
Partial eclipse, when the Moon first enters Earth’s dark umbral shadow, begins at 5:16 a.m. CDT near the start of morning twilight. Totality begins at 6:58 a.m. with the Moon already set for the eastern half of the country. Credit: Fred Espenak

This eclipse will also be the shortest total eclipse of the 21st century; our satellite spends just 4 minutes and 43 seconds inside Earth’s umbra or shadow core. That’s only as long as a typical solar eclipse totality. Ah, the irony.

Better have your camera ready or you’ll miss it. The maps below show the maximum amount of the Moon visible shortly before setting from two eastern U.S. cities and the height of the totally eclipsed Moon from two western locations. Click each panel for more details about local circumstances.

The Earth's shadow will take only a small bite out of the Moon before sunrise (6:47 a.m.) as seen from Washington D.C. Source: Stellarium
The Earth’s shadow will take only a small bite out of the Moon before sunrise (6:47 a.m.) as seen from Washington D.C. From all mainland U.S. locations Virgo’s brightest star Spica will appear about 10° to the left of the Moon. Source: Stellarium
Here's the view from Chicago where sunrise occurs at 6:27 a.m. Source: Stellarium
Here’s the view from Chicago where sunrise occurs at 6:27 a.m.  Source: Stellarium
Totality will be visible From Denver, Colorado with the Moon low in the western sky. Source: Stellarium
Totality will be visible From Denver, Colorado with the Moon low in the western sky in morning twilight. Sunrise is 6:42 a.m. Source: Stellarium
Seattle and the West Coast get a great view of totality in a dark sky. The final partial phases will also be visible. Sunrise there is 6:40 a.m. Source: Stellarium
Seattle and the West Coast get a great view of totality in a dark sky. The final partial phases will also be visible. Sunrise there is 6:40 a.m. Source: Stellarium

Now that you know times and shadow coverage, let’s talk about the fun part — what to look for as the event unfolds. You’ll need to find a location in advance with a good view to the southwest as most of the action happens in that direction. Once that detail’s taken care of and assuming clear weather, you can kick back in a folding chair or with your back propped against a hillside and enjoy.

During the early partial phases you may not see the shadowed portion of the Moon with the naked eye. Binoculars and telescopes will show it plainly. But once the Moon's about 50% covered, the reddish-orange tint of the shadowed half becomes obvious. Credit: Jim Schaff
During the early partial phases you may not see the shadowed portion of the Moon with the naked eye. Binoculars and telescopes will show it plainly. But once the Moon is about 50% covered, the reddish-orange tint of the shadowed half becomes obvious. During total eclipse (right), the color is intense.  Credit: Jim Schaff

The entire eclipse can be enjoyed without any optical aid, though I recommend a look through binoculars now and then. The eclipsed Moon appears distinctly three-dimensional with only the slightest magnification, hanging there like an ornament among the stars. The Earth’s shadow appears to advance over the Moon, but the opposite is true; the Moon’s eastward orbital motion carries it deeper and deeper into the umbra.

Nibble by nibble the sunlit Moon falls into shadow. By the time it’s been reduced to half, the shaded portion looks distinctly red even to the naked eye. Notice that the shadow is curved. We live on a spherical planet and spheres cast circular shadows. Seeing the globe of Earth projected against the Moon makes the roundness of our home planet palpable.

Artist view of Earth totally eclipsing the sun as viewed from the moon. Low angled sunlight filtered by our atmosphere is reddened in exactly the same way a setting sun is reddened. That red light bathes the moon’s surface which reflects a bit of it back toward Earth, giving us a red moon during totality.
A simulated view looking back at Earth from the Moon during a total lunar eclipse on Earth. Sunlight grazing Earth’s circumference gets filtered by our atmosphere in exactly the same way the setting or rising Sun looks red. All the cooler colors have been scattered away by air and Red light, bent into the umbra by atmospheric refraction, bathes the lunar surface in red. As you might have guessed, when we see a total lunar eclipse on Earth, lunar inhabitants see a total eclipse of the Sun by Earth. Source: Stellarium

When totality arrives, the entire lunar globe throbs with orange, copper or rusty red. These sumptuous hues originate from sunlight filtered and bent by Earth’s atmosphere into the umbral shadow. Atmospheric particles have removed all the cooler colors, leaving the reds and oranges from a billion sunrises and sunsets occurring around the planet’s circumference. Imagine for a moment standing on the Moon looking back. Above your head would hang the black disk of Earth, nearly four times the size of the Moon in our sky, ringed by a narrow corona of fiery light.

Color varies from one eclipse to the next depending on the amount of water, dust and volcanic ash suspended in Earth’s atmosphere. The December 30, 1982 eclipse was one of the darkest in decades due to a tremendous amount of volcanic dust from the eruption of the Mexican volcano El Chichon earlier that year.

The more particles and haze, the greater the light absorption and darker the Moon. That said, this eclipse should be fairly bright because the Moon does not tread deeply into Earth’s shadow. It’s in for a quick dip of totality and then resumes partial phases.

The Moon's color can vary from yellow-orange to dark, smoky brown during totality depending on the state of the atmosphere. You can also see lots of stars in the sky right up to the Moon's edge when it's in Earth's shadow. This photo from last April's eclipse. Credit: Bob King
The Moon’s color can vary from yellow-orange to dark, smoky brown during totality depending on the state of the atmosphere. You can also see lots of stars in the sky right up to the Moon’s edge when it’s in Earth’s shadow. This photo from last April’s eclipse. Spica is below the Moon and Mars to the right. Credit: Bob King

It’s northern edge, located close to the outer fringe of Earth’s umbra, should appear considerably brighter than the southern, which is closer to the center or darkest part of the umbra.

Earth's shadow exposed! During a lunar eclipse that occurs at dusk or dawn (like the April 4th one and this one last October) we have the rare opportunity to see Earth's shadow on the distant Moon at the same time it's visible as a dark purple band cast on the upper atmosphere as seen here on October 8, 2015. Credit: Bob King
Earth’s shadow exposed! When a lunar eclipse occurs at dusk or dawn we have the rare opportunity to see Earth’s shadow on the distant Moon at the same time it’s visible as a dark purple band cast on the upper atmosphere as seen here on October 8, 2015. Credit: Bob King

Besides the pleasure of seeing the Moon change color, watch for the sky to darken as totality approaches. Eclipses begin with overwhelming moonlight and washed out, star-poor skies. As the Moon goes into hiding, stars return in a breathtaking way over a strangely eerie landscape. Don’t forget to turn around and admire the glorious summer Milky Way rising in the eastern sky.

Lunar eclipses remind us we live in a Solar System made of these beautiful, moving parts that never fail to inspire awe when we look up to notice.

In case you can’t watch the eclipse from your home due to weather or circumstance, our friends at the Virtual Telescope Project  and SLOOH will stream it online.

Posted on by Ken Kremer

World’s Most Powerful Solid Booster Set for Space Launch System Test Firing on March 11

Orbital ATK’s five segment rocket motor is assembled in its Promontory, Utah, test stand where it is being conditioned for the March 11 ground test. Credit: Orbital ATK

All systems are go for the inaugural ground test firing on March 11 of the world’s most powerful solid rocket booster ever built that will one day power NASA’s mammoth new Space Launch System (SLS) heavy lift rocket and propel astronauts to deep space destinations.

The booster known as qualification motor, QM-1, is the largest solid rocket motor ever built and will be ignited on March 11 for a full duration static fire test by prime contractor Orbital ATK at the newly merged firms test facility in Promontory, Utah.

Ignition of the horizontally mounted motor is planned for 11:30 a.m. EDT (9:30 a.m. MDT) on Wednesday, March 11 on the T-97 test stand.

The test will be broadcast live on NASA TV.

Engineers at Orbital ATK in Promontory, Utah, prepare to test the booster that will help power NASA’s Space Launch System to space to begin missions to deep space, including to an asteroid and Mars. A test on March 11 is one of two that will qualify the booster for flight. Image Credit: Orbital ATK
Engineers at Orbital ATK in Promontory, Utah, prepare to test the booster that will help power NASA’s Space Launch System to space to begin missions to deep space, including to an asteroid and Mars. A test on March 11 is one of two that will qualify the booster for flight. Image Credit: Orbital ATK

The two minute long, full duration static test firing of the motor marks a major milestone in the ongoing development of NASA’s SLS booster, which is the most powerful rocket ever built in human history.

The 5-segment booster produces 3.6 million lbs of maximum thrust which equates to more than 14 Boeing 747-400s at full takeoff power!

The new 5-segment booster is directly derived from the 4-segment booster used during NASA’s three decade long Space Shuttle program. One segment has been added and therefore the new, longer and more powerful booster must be requalified to launch the SLS and humans.

A second test is planned a year from now and will qualify the boosters for use with the SLS.

Teams of engineers, operators, inspectors and program managers across Orbital ATK’s Flight Systems Group have spent months getting ready for the QM-1 test. To prepare they started countdown tests on Feb 25.

“The crew officially starts daily countdown test runs of the systems this week, at T-15 days,” said Kevin Rees, director, Test & Research Operations at Orbital ATK.

“These checks, along with other test stand calibrations, will verify all systems are ready for the static test. Our team is prepared and we are proud to play such a significant role on this program.”

The first qualification motor for NASA's Space Launch System's booster is installed in ATK's test stand in Utah and is ready for a March 11 static-fire test. Credit: ATK
The first qualification motor for NASA’s Space Launch System’s booster is installed in ATK’s test stand in Utah and is ready for a March 11 static-fire test. Credit: ATK

The QM-1 booster is being conditioned to 90 degrees and the static fire test will qualify the booster design for high temperature launch conditions. It sits horizontally in the test stand and measures 154 feet in length and 12 feet in diameter and weighs 801 tons.

The static fire test will collect data on 103 design objectives as measured through more than 534 instrumentation channels on the booster it is firing.

The second booster test in March 2016 will be conducted at lower temperature to qualify the lower end of the launch conditions at 40 degrees F.

The first stage of the SLS will be powered by a pair of the five-segment boosters and four RS-25 engines that will generate a combined 8.4 million pounds of liftoff thrust.

The SLS is designed to propel the Orion crew capsule to deep space destinations, including the Moon, asteroids and the Red Planet.

The maiden test flight of the SLS is targeted for no later than November 2018 and will be configured in its initial 70-metric-ton (77-ton) version with a liftoff thrust of 8.4 million pounds. It will boost an unmanned Orion on an approximately three week long test flight beyond the Moon and back.

NASA plans to gradually upgrade the SLS to achieve an unprecedented lift capability of 130 metric tons (143 tons), enabling the more distant missions even farther into our solar system.

The first SLS test flight with the uncrewed Orion is called Exploration Mission-1 (EM-1) and will launch from Launch Complex 39-B at the Kennedy Space Center.

Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA
Solid rocket boosters separate from SLS core stage in this artists concept. Credit: NASA

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

Orion’s inaugural mission dubbed Exploration Flight Test-1 (EFT) was successfully launched on a flawless flight on Dec. 5, 2014 atop a United Launch Alliance Delta IV Heavy rocket Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Launch pad remote camera view. Credit: Ken Kremer - kenkremer.com
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Launch pad remote camera view. Credit: Ken Kremer – kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

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Learn more about MMS, Mars rovers, Orion, SpaceX, Antares, NASA missions and more at Ken’s upcoming outreach events:

Mar 9-11: “MMS, Orion, SpaceX, Antares, Curiosity Explores Mars,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA's Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built. Credit: Ken Kremer - kenkremer.com
NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA’s Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built. Credit: Ken Kremer – kenkremer.com
Posted on by Bob King

How to Photograph Tonight’s Spectacular Triple-Play Conjunction

Last night's one-day-old Moon photographed a half-hour after sunset. Details: handheld camera ISO 400, f/2.8, 1/15". Credit: Bob King

Tonight the thin, 2-day-old crescent Moon will join Venus and Mars in the western sky at dusk for one of the most striking conjunctions of the year. The otherworldly trio will fit neatly with a circle about 1.5° wide or just three times the diameter of the full moon. No question, this will catch a lot of eyes around the world. Why not take a picture and share it with your friends? Here are a few tips to do just that.

Moon, Mars and Venus around 6:45 p.m. (CST) on Feb. 20 in the western sky. Be sure to look for the darkly-lit part of the moon illuminated by sunlight reflecting off Earth called earthshine. It’s a beautiful sight in binoculars. Source: Stellarium
Moon, Mars and Venus around 6:45 p.m. (CST) on Feb. 20 in the western sky. Be sure to look for the darkly-lit part of the moon illuminated by sunlight reflecting off Earth called earthshine. Source: Stellarium, author

You won’t need much for an easy snapshot. In bright twilight, point your mobile phone toward the Moon and tap off a few shots, taking care not to touch the screen too hard lest you shake the phone and blur the image. The phone’s autoexposure and autofocus settings should be adequate to capture both the Moon and Venus. Mars is fainter and may only show if you can steady your phone against something to allow for a longer exposure without blurring. Assuming you use your phone in its default wide view, the Moon, Venus and Mars will form a tight, small group in a larger scene.

Last night, Feb. 19, Venus and Mars were 1 degree apart. Tonight they'll be even closer at just over 1/2° with the Moon a degree or so to their right. Credit: Bob King
Last night, Feb. 19, Venus and Mars were 1°apart. Tonight they’ll be even closer at just over 1/2° with the Moon about 1° to their right. Details: 65 minutes after sunset (mid-twilight), camera on tripod, 35mm lens at f/2.8, ISO 400 and 6 second exposure. Credit: Bob King

Phones provide the highest resolution in their wide setting. If you zoom in, the Moon will be bigger but resolution or sharpness will suffer. Someday phones will be as good as digital single lens reflex cameras (DSLRs) but until then, you’ll need one of these or their cousins, the point-and-shoot cameras, to get the best images of astronomical objects.

You’ll also need a tripod to keep the camera still and stable during the longer exposures you’ll need during the optimum time for photography which begins about 30 minutes after sunset. That’s when your photos will capture all three objects without overexposing the Moon and making it look washed-out. Ideally, you want to see the bright crescent contrasting with the dim glow of the earthshine.

Venus and Mars photographed in mid-twilight with a 100mm telephoto lens at f/2.8. To prevent trailing of the planets, I cut the exposure in half to 4 seconds and increased the camera's ISO to 800. Credit: Bob King
Venus and Mars photographed in mid-twilight with a 100mm telephoto lens at f/2.8. To prevent trailing of the planets, I cut the exposure in half to 4 seconds and increased the camera’s ISO to 800. Credit: Bob King

Lucky for us, the Moon’s sharp form makes an ideal target for the camera’s autofocus. Frame an attractive landscape or ask a friend to stand in the foreground. Set your lens to its widest open setting (usually f/2.8-3.5) and the ISO (your camera’s sensitivity to light) to 800. The higher the ISO, the shorter the exposure you can use to capture an image, but high ISOs introduce unwanted noise and graininess. 800’s a good compromise. If you can manually set your exposure, start at 4 seconds.

Compose your photo and then focus on the Moon and gently press the shutter button. Check the image on the back screen. Are you on target or is it too dark? If so, double the time. If too bright, half it. As the sky gets darker, you’ll need to gradually increase your exposure. That’s when the Moon will start to wash out and the beautiful deep blue sky turn black or the color of your local light pollution. Around here, that’s pinkish-orange. I’ve got lots of orange sky photos to prove it!

The key to good photos in twilight is balancing the different types of lighting - dusk, the sunlit crescent, the earth-lit portion and the planets. Shoot pictures at a variety of exposures between about 30-60 minutes after sunset when the western sky is still aglow but the Moon is bright and obvious. Credit: Bob King
Mercury and the Moon on Jan. 31, 2014. Besides finding a scene you like, the key to good photos in twilight is balancing the different types of lighting – dusk, the sunlit crescent, the earth-lit outline and the planets. Shoot pictures at a variety of exposures starting about 35 minutes after sunset when the western sky is still aglow but the Moon is bright and obvious. Credit: Bob King

All told, you can use a mobile phone to shoot from about 25-40 minutes after sunset and a DSLR from 25 minutes to 75 minutes after. If you’re shooting with a standard 24-35mm lens, keep your exposures under 20 seconds or the Moon and planets will start to streak or trail. The Rule of 500 is a great way to remember how long a time exposure you can make with any lens before celestial objects start trailing. So, 500/24mm = 20.8 seconds and 500/200mm (telephoto) = 2.5 seconds. That means if you plan to shoot the conjunction with a longer lens, you’ll need to up your ISO to 1600 or even 3200 in late twilight to get a tack-sharp, motionless photo.

I screwed this photo up of the Moon, Jupiter and Mars by overexposing the sunlit crescent. Credit: Bob King
I screwed this photo up of the Moon, Jupiter and Mars by overexposing the sunlit crescent. It’s all part of learning the ropes, a task made much easier nowadays by simply checking the view screen of your camera and trying a different exposure. Credit: Bob King

Telephoto images are a bit more challenging, but they increase the size of the pretty trio within the scene. When shooting telephoto images (even wide ones if you’re fussy), shoot them on self-timer. That’s the setting everyone used before the selfie took the world by storm. Most timers are pre-set to 10 seconds. You press it and the camera counts down 10 seconds before automatically tripping the shutter, allowing you time to put yourself in a group photo.

In astrophotography, using the self-timer assures you’re going to get a vibration-free photo. If it’s cold out and you’re shooting with a telephoto, vibration from your finger pressing the shutter button can jiggle the image.

Good luck tonight and clear skies! If you have any questions, please ask.

Posted on by Nancy Atkinson

Astrophotos: The February 2015 ‘Black’ Moon

The February 2015 new Moon over Antelope Valley, California. Credit and copyright: Gavin Heffernan.

As our David Dickinson noted in his recent article, a new term is “creeping into the popular astronomical vernacular: that of a ‘Black Moon’.” This is the New Moon version of a Blue Moon, and is either:

  1. A month missing a Full or New Moon… this can only occur in February, as the lunar synodic period from like phase to phase is 29.5 days long. This last occurred in 2014 and will next occur in 2018.
  2. The second New Moon in a month with two. This can happen in any calendar month except February.
  3. And now for the most convoluted definition: the third New Moon in an astronomical season with four.

The February 18th New Moon met the requirements expressed in rule 3. The fourth New Moon of the season falls on March 20th, just 13 hours before the northward equinox on the same date.

But no matter what the occasion, there are always astrophotographers out to grab pictures, and here are some shared with Universe Today via email and on our Flickr page.

The sliver of the February 2015 new 'black' Moon. Credit and copyright: Héctor Barrios.
The sliver of the February 2015 new ‘black’ Moon. Credit and copyright: Héctor Barrios.
The less than 24-hour old Moon on February 19, 2015, as seen from Toronto, Canada. Credit and copyright: Michael Watson.
The less than 24-hour old Moon on February 19, 2015, as seen from Toronto, Canada. Credit and copyright: Michael Watson.
The Moon, Mars and Venus. Credit and copyright: Neil Ghosh.
The Moon, Mars and Venus. Credit and copyright: Neil Ghosh.

And remember, tonight you can see a close conjunction of the Moon, Venus and Mars. Here’s how you can photograph the event, and make sure to share your photos with Universe Today!