Moon Archives

September 1, 2015December 23, 2015 by David Dickinson

Watch the Moon Occult Aldebaran This Weekend

How about that perigee Full Moon this past weekend? Thus begins ‘Supermoon season’ for 2015, as this month’s Full Moon occurs even closer to perigee — less than an hour apart, in fact — on September 28^th, with the final total lunar eclipse of the ongoing tetrad to boot. Keep an eye on Luna this week, as it crosses into the early AM sky for several key dates with destiny just prior to the start of the second and final eclipse season for 2015.

The big event later this week is a passage of the waning gibbous Moon through the Hyades open cluster on the morning of Saturday, September 5^th, climaxing with a dramatic occultation of the bright star Aldebaran on the same morning. This is part of a series of 49 ongoing occultations of Aldebaran by the Moon, one for each lunation extending out to September 2018.

This weekend’s event will occur at moonrise under nighttime skies for the northeastern United States and the Canadian Maritimes, and near dawn and under daytime skies for observers in Western Europe and Northern Africa eastward. We observed an occultation of Aldebaran by the Moon under daytime skies from Alaska back in the late 1990s, and can attest that the star is indeed visible near the limb of the Moon in binoculars. A good deep blue sky is key to spotting +1 magnitude Aldebaran in the daytime.

London 711 AM — The view from London UK at 7:11 AM local. Image Credit: Starry Night Education software

During waning phase, the bright edge of the Moon is always leading, meaning Aldebaran will ingress (wink out) on the bright limb of the 52% illuminated Moon, and egress (reappear) along its dark limb.

Here are some key times for ingress/egress by location (all times quoted are local and incorporate daylight saving/summer time):

Washington D.C.

Moonrise: 11:53 PM

Ingress: N/A (before Moonrise)

Egress: 12:38 AM (altitude = 8 degrees)

Boston

Moonrise: 11:22 PM

Ingress 11:57 PM (altitude = 6 degrees)

Egress: 12:41 AM (altitude = 14 degrees)

Gander, Newfoundland

Moonrise: 11:26 PM

Ingress: 1:37 AM (altitude = 20 degrees)

Egress: 2:26 AM (altitude = 28 degrees)

London

Moonrise: 11:04 PM

Ingress: 5:50 AM (altitude = 53 degrees)

Sunrise: 6:18 AM

Egress: 7:07 AM (altitude = 54 degrees)

Paris

Moonrise: 12:02 AM

Ingress: 6:53 AM (altitude = 56 degrees)

Sunrise: 7:12 AM

Egress: 8:10 AM (altitude = 57 degrees)

Occultations of bright stars by the Moon are one of the few times besides a solar or lunar eclipse when you can actually discern the one degree per every two and half hours orbital motion of the Moon in real time. The Moon moves just a little more than its own apparent diameter as seen from the Earth every hour. This also sets us up for four more fine occultations of Aldebaran by the Moon alternating between Europe and North America on October 2^nd, October 29^th, November 26^th, and December 23^rd.

The bright stars Antares, Spica and Regulus also lie along the path of the Moon, which is inclined about five degrees relative to the ecliptic. A series of occultations of Regulus by the Moon begins in late 2016.

Fun fact: The Moon used to occult the bright star Pollux in the constellation Gemini until about 2100 years ago in 117 BC. The 26,000 year cycle known as the Precession of the Equinoxes has since carried the star out of the Moon’s path.

Observations of occultations — especially dramatic grazes spied right from the edge of the path — can be used to construct a profile of the lunar limb. A step-wise ‘wink out’ of a star during an occultation can also betray the existence of a close binary.

Recording an occultation of a star by the Moon is as easy as running video while shooting the Moon. The dark limb egress of Aldebaran will be much easier to record during the September 5^th event than the ingress of the star against the bright limb. I typically run video with a DLSR directly coupled to a Celestron 8” SCT telescope, with WWV radio running in the background for a precise audio timing of the event. Remember, the Moon will also be transiting the Hyades star cluster as well, covering and uncovering many fainter stars for observers worldwide around the same time frame.

Sept 5 5UT — The Last Quarter Moon versus Aldebaran and the Hyades on September 5th at ~5:00 UT. Image credit: Stellarium

Now for the ‘wow’ factor. The Moon is about 240,000 miles (400,000 km), or 1 1/4 light seconds distant. Aldebaran is 65 light years away, and said light left the star around 1950, only to have its light ‘rejected’ during the very last second by the craggy mountains along the lunar limb. And though Aldebaran appears to be a member of the Hyades, it isn’t, as the open cluster sits 153 light years from Earth.

And watch that Moon, as it then heads for a partial solar eclipse as seen from South Africa and the southern Indian Ocean on September 13th, and a total lunar eclipse visible from North America and Europe on September 28th.

Expect more to come, with complete guides to both on Universe Today!

August 30, 2015December 23, 2015 by Ken Kremer

NASA Tests Orion’s Fate During Parachute Failure Scenario

A test version of NASA's Orion spacecraft successfully landed under two main parachutes in the Arizona desert Aug. 26, 2015 at the U.S. Army's Yuma Proving Ground. Credit: NASA

What would happen to the astronaut crews aboard NASA’s Orion deep space capsule in the event of parachute failures in the final moments before splashdown upon returning from weeks to years long forays to the Moon, Asteroids or Mars?

NASA teams are evaluating Orion’s fate under multiple scenarios in case certain of the ships various parachute systems suffer partial deployment failures after the blistering high speed reentry into the Earth’s atmosphere.

Orion is nominally outfitted with multiple different parachute systems including two drogue chutes and three main chutes that are essential for stabilizing and slowing the crewed spacecraft for safely landing in the Pacific Ocean upon concluding a NASA ‘Journey to Mars’ mission.”

This week engineers from NASA and prime contractor Lockheed Martin ran a dramatic and successful six mile high altitude drop test in the skies over the Arizona desert, in the instance where one of the parachutes in each of Orion’s drogue and main systems was intentionally set to fail.

“We test Orion’s parachutes to the extremes to ensure we have a safe system for bringing crews back to Earth on future flights, even if something goes wrong,” says CJ Johnson, project manager for Orion’s parachute system, in a statement.

“Orion’s parachute performance is difficult to model with computers, so putting them to the test in the air helps us better evaluate and predict how the system works.”

Although Orion hits the atmosphere at over 24,000 mph after returning from deep space, it slows significantly after atmospheric reentry.

By the time the first parachutes normally deploy, the crew module has decelerated to some 300 mph. Their job is to slow the craft down to about 20 mph by the time of ocean splashdown mere minutes later.

On Aug. 26, NASA conducted a 35,000 foot high drop test out of the cargo bay of a C-17 aircraft using an engineering test version of the Orion capsule over the U.S. Army Yuma Proving Ground in Yuma, Arizona.

“The engineering model has a mass similar to that of the Orion capsule being developed for deep space missions, and similar interfaces with its parachute system,” say officials.

“Engineers purposefully simulated a failure scenario in which one of the two drogue parachutes, used to slow and stabilize Orion at high altitude, and one of its three main parachutes, used to slow the crew module to landing speed, did not deploy.”

Here’s a video detailing the entire drop test sequence of events from preflight preparations to the parachute landing.

The high-risk Aug. 26 experiment was NASA’s penultimate drop test in this engineering evaluations series. A new series of tests in 2016 will serve to qualify the parachute system for crewed flights.

Engineers prepare to test the parachute system for NASA’s Orion spacecraft at the U.S. Army Yuma Proving Ground in Yuma, Arizona on Aug. 26, 2015 by loading a test version on a C-17 aircraft. 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.

The parachutes operated flawlessly during the Orion EFT-1 mission.

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. 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. Credit: Ken Kremer – kenkremer.com

Orion’s next launch is set for the uncrewed test flight called Exploration Mission-1 (EM-1). It will blast off on the inaugural flight of NASA’s SLS heavy lift monster rocket concurrently under development – from Launch Complex 39-B at the Kennedy Space Center.

The maiden SLS test flight 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.

Toward that goal, NASA is also currently testing the RS-25 first stage engines that will power SLS – as outlined in my recent story here.

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.

Homecoming view of NASA’s first Orion spacecraft after returning to NASA’s Kennedy Space Center in Florida on Dec. 19, 2014 after successful blastoff on Dec. 5, 2014. Credit: Ken Kremer - kenkremer.com — Parachutes are stowed atop Orion
Homecoming view of NASA’s first Orion spacecraft after returning to NASA’s Kennedy Space Center in Florida on Dec. 19, 2014 after successful blastoff on Dec. 5, 2014. 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 MUOS-4 USAF launch, Orion, SLS, SpaceX, Boeing, ULA, Space Taxis, Mars rovers, Orbital ATK, Antares, NASA missions and more at Ken’s upcoming outreach events:

Aug 31- Sep 2: “MUOS-4 launch, Orion, Commercial crew, Curiosity explores Mars, Antares and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

August 30, 2015December 23, 2015 by Bob King

Eclipse By Fire! Smoky Haze Pervades Night Sky, Darkens Moon

The Full Moon at 10:30 p.m. last night (Aug. 30). Even at 25 altitude, it glowed a deep, dark orange due to heavy smoke from western forest fires. Credit: Bob King

Did you see the Moon last night? I walked outside at 10:30 p.m. and was stunned to see a dark, burnt-orange Full Moon as if September’s eclipse had arrived a month early. Why? Heavy smoke from forest fires in Washington, California and Montana has now spread to cover nearly half the country in a smoky pall, soaking up starlight and muting the moonlight.

If this is what global warming has in store for us, skywatchers will soon have to take a forecast of “clear skies” with a huge grain of salt.

The Pacific Northwest is abundantly dotted with wildfires in Washington, Oregon, Idaho and Montana.This natural-color satellite image was made using the Aqua satellite on August 25, 2015. Actively burning areas, detected by MODIS’s thermal bands, are outlined in red. Credit: NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team — The Pacific Northwest is abundantly dotted with wildfires in Washington, Oregon, Idaho and Montana in this Aqua satellite image taken on August 25, 2015. Actively burning areas, detected by MODIS’s thermal bands, are outlined in red. Smoke from the fires has been drifting east, blanketing Midwestern skies and blotting out the stars at night. Credit: NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team

By day, the sky appears the palest of blues. By night, the stars are few if any, and the Moon appears faint, the color of fire and strangely remote. Despite last night’s clear skies, only the star Vega managed to penetrate the gloom. I never saw my shadow even at midnight when the Moon had climbed high into the southern sky.

Last night's Full Moon seen through an 8-inch telescope. The colors are true. Credit: Bob King — Last night’s Full Moon seen through an 8-inch telescope at 11:30 p.m. The colors are true. Credit: Bob King

We’ve seen this smoke before. Back in July, Canadian forest fires wafted south and west and covered much of the northern half of the U.S., giving us red suns in the middle of the afternoon and leaving only enough stars to count with two hands at night. On the bright side, the Moon is fascinating to observe. I set up the telescope last night and spend a half hour watching this unexpected “eclipse”; sunsets appear positively atomic. The size of the smoke particles is just right for filtering out or scattering away blues, greens and even yellow from white light. Vivid reds, pinks and oranges remain to tint anything bright enough to penetrate the haze.

GOES-8 satellite view of the central U.S. taken at 8:15 a.m. CDT August 30, 2015 show a veil of grayish forest fire smoke covering much of the Midwest with clearer conditions to the southeast. The red line is the approximate border between the two. Credit: NOAA

But smoke can cause harm, too. Forest fire smoke contains carbon monoxide, carbon dioxide and soot. On especially smoky days, you can even smell the odor of burning trees in the air at ground level. Some may suffer from burning eyes, asthma or bronchitis on especially smoky days even a thousand miles from the source fires.

Wide-angle view of last night's melon Moon. Notice that the smoke is thicker along the horizontal left and right of the Moon. Above, at a higher elevation, we see through less smoke, so the moonlit sky is a little brighter there. No stars are visible. Credit: Bob King — Wide-angle view of last night’s Moon. Notice that the smoke is thicker along the horizontal – left and right of the Moon. Above, at a higher elevation, we see through less smoke, so the moonlit sky is a bit brighter there. No stars are visible. Credit: Bob King

On clear, blue-sky days, I’ve watched the smoke creep in from the west. It begins a light haze and slowly covers the entire sky in a matter of several hours, often showing a banded structure in the direction of the Sun. A little smoke is OK for observing, but once it’s thick enough to redden the Moon even hours after moonrise, you can forget about using your telescope for stargazing. Sometimes, a passing thunderstorm and cold front clears the sky again. Sometimes not.

The only cures for fire soot are good old-fashioned rain and the colder weather that arrives with fall. In the meantime, many of us will spend our evenings reading about the stars instead of looking at them.

August 28, 2015December 23, 2015 by Bob King

August Full Moon Anticipates September’s Total Lunar Eclipse

A Full Moon in all its horizontal glory. When near the horizon, refraction squeezes the lunar disk into an oval. Scattering removes the shorter wavelengths of white light, leaving the Moon a rich red or orange. Credit: Bob King

Who doesn’t love a Full Moon? Occurring about once a month, they never wear out their welcome. Each one becomes a special event to anticipate. In the summer months, when the Moon rises through the sultry haze, atmosphere and aerosols scatter away so much blue light and green light from its disk, the Moon glows an enticing orange or red.

At Full Moon, we’re also more likely to notice how the denser atmosphere near the horizon squeezes the lunar disk into a crazy hamburger bun shape. It’s caused by atmospheric refraction. Air closest to the horizon refracts more strongly than air near the top edge of the Moon, in effect “lifting” the bottom of the Moon up into the top. Squished light! We also get to see all the nearside maria or “seas” at full phase, while rayed craters like Tycho and Copernicus come into their full glory, looking for all the world like giant spatters of white paint even to the naked eye.

At full phase, the Moon lies directly opposite the Sun on the other side of Earth. Sunlight hits the Moon square on and fully illuminates the Earth-facing hemisphere. Credit: Bob King

Tomorrow night (August 29), the Full Sturgeon Moon rises around sunset across the world. The name comes from the association Great Lakes Indian groups made between the August moon and the best time to catch sturgeon. Next month’s moon is the familiar Harvest Moon; the additional light it provided at this important time of year allowed farmers to harvest into the night.

A Full Moon lies opposite the Sun in the sky exactly like a planet at opposition. Earth is stuck directly between the two orbs. As we look to the west to watch the Sun go down, the Moon creeps up at our back from the eastern horizon. Full Moon is the only time the Moon faces Sun directly – not off to one side or another – as seen from Earth, so the entire disk is illuminated.

The moon provides the perfect backdrop for watching birds migrate at night. Observers with spotting scopes and small telescopes can watch the show anytime the moon is at or near full. Photo illustration: Bob King — The moon provides the perfect backdrop for watching birds migrate at night. Although a small telescope is best, you might see an occasional bird in binoculars, too. Credit: Bob King

If you’re a moonrise watcher like I am, you’ll want to find a place where you can see all the way down to the eastern horizon tomorrow night. You’ll also need the time of moonrise for your city and a pair of binoculars. Sure, you can watch a moonrise without optical aid perfectly well, but you’ll miss all the cool distortions happening across the lunar disk from air turbulence. Birds have also begun their annual migration south. Don’t be surprised if your glass also shows an occasional winged silhouette zipping over those lunar seas.

Because the Moon's orbit is tilted 5.1 degrees with respect to Earth's, it normally passes above or below Earth's shadow with no eclipse. Only when the lineup is exact, does the Moon then pass directly behind Earth and into its shadow. Credit: Bob King — Because the Moon’s orbit is tilted 5.1° with respect to Earth’s, it normally passes above or below Earth’s shadow with no eclipse — either lunar or solar. Only when the lineup is exact, does the Moon pass directly behind Earth and into its shadow. Credit: Bob King

Next month’s Full Moon is very special. A few times a year, the alignment of Sun, Earth and Moon (in that order) is precise, and the Full Moon dives into Earth’s shadow in total eclipse. That will happen overnight Sunday night-Monday morning September 27-28. This will be the final in the current tetrad of four total lunar eclipses, each spaced about six months apart from the other. I think this one will be the best of the bunch. Why?

The totally eclipsed moon on April 15, 2014 from Duluth, Minn. This was the first in the series of four eclipses called a tetrad. Some refer to this lunar eclipse as a “Blood Moon” because it coincides with the Jewish Passover. Credit: Bob King — The totally eclipsed moon on April 15, 2014 from Duluth, Minn. This was the first in the series of four eclipses called a tetrad. September’s totally eclipsed Moon will appear similar. The coloring comes from sunlight grazing the edge of Earth’s atmosphere and refracted by it into the planet’s shadow. Credit: Bob King

Convenient evening viewing hours (CDT times given) for observers in the Americas. Partial eclipse begins at 8:07 p.m., totality lasts from 9:11 – 10:23 p.m. and partial eclipse ends at 11:27 p.m. Those times mean that for many regions, kids can stay up and watch.
The Moon passes more centrally through Earth’s shadow than during the last total eclipse. That means a longer totality and possibly more striking color contrasts.
September’s will be the last total eclipse visible in the Americas until January 31, 2018. Between now and then, there will be a total of four minor penumbral eclipses and one small partial. Slim pickings.

Diagram showing the details of the upcoming total lunar eclipse. The event begins when the Moon treads into Earth's outer shadow (penumbra) at 7:12 p.m. CDT. Partial phases start at 8:07 and totality at 9:11. Credit: NASA / Fred Espenak — Diagram showing the details of the upcoming total lunar eclipse. The event begins when the Moon treads into Earth’s outer shadow (penumbra) at 7:12 p.m. CDT. Partial phases start at 8:07 and totality at 9:11. Credit: NASA / Fred Espenak

Not only will the Americas enjoy a spectacle, but totality will also be visible from Europe, Africa and parts of Asia. For eastern hemisphere skywatchers, the event will occur during early morning hours of September 28. Universal or UT times for the eclipse are as follows: Partial phase begin at 1:07 a.m., totality from 2:11 – 3:23 a.m. with the end of partial phase at 4:27 a.m.

Eclipse visibility map. Credit: NASA / Fred Espenak — September 27-28, 2015 eclipse visibility map. Credit: NASA / Fred Espenak

We’ll have much more coverage on the upcoming eclipse in future articles here at Universe Today. I hope this brief look will serve to whet your appetite and help you anticipate what promises to be one of the best astronomical events of 2015.

August 26, 2015December 23, 2015 by David Dickinson

Ice Giants at Opposition

It seems as if the planets are fleeing the evening sky, just as the Fall school star party season is getting underway. Venus and Mars have entered the morning sky, and Jupiter reaches solar conjunction this week. Even glorious Saturn has passed eastern quadrature, and will soon depart evening skies.

Enter the ice giants, Uranus and Neptune. Both reach opposition for 2015 over the next two months, and the time to cross these two out solar system planets off your life list is now.

Aug 26 — Looking east at dusk in late August, as Uranus and Neptune rise. Image credit: Stellarium

First up, the planet Neptune reaches opposition next week in the constellation Aquarius on the night of August 31^st/September 1^st. Shining at magnitude +7.8, Neptune spends the remainder of 2015 about three degrees southwest of the +3.7 magnitude star Lambda Aquarii. It’s possible to spot Neptune using binoculars, and about x100 magnification in a telescope eyepiece will just resolve the blue-grey 2.3 arc second disc of the planet. Though Neptune has 14 known moons, just one, Triton, is within reach of a backyard telescope. Triton shines at magnitude +13.5 (comparable to Pluto), and orbits Neptune in a retrograde path once every 6 days, getting a maximum of 15” from the disk of the planet.

Nep Aug-Nov Triton aug 31 — The path of Neptune from late August through early November 2015. Inset: the position of Neptune’s moon Triton on the evening of August 31st: Image credit: Starry Night Education software

Uranus reaches opposition on October 11^th in the adjacent constellation Pisces. Keep an eye on Uranus, as it nears the bright +5.2 magnitude star Zeta Piscium towards the end on 2015. Shining at magnitude +5.7 with a 3.6 arc second disk, Uranus hovers just on the edge of naked eye visibility from a dark sky site.

Credit — Uranus, left of the eclipsed Moon last October. Image credit and copyright: A Nartist

It’ll be worth hunting for Uranus on the night of September 27^th/28^th, when it sits 15 degrees east of the eclipsed Moon. Uranus turned up in many images of last Fall’s total lunar eclipse. This will be the final total lunar eclipse of the current tetrad, and the Moon will occult Uranus the evening after for the South Atlantic. This is part of a series of 19 ongoing occultations of Uranus by the Moon worldwide, which started in August 2014, and end on December 20^th, 2015. After that, the Moon will move on and begin occulting Neptune next year in June through the end of 2017.

Occultation — The visibility footprint of the September 29th occultation of Uranus by the Moon. Image credit: Occult 4.0.

Uranus has 27 known moons, four of which (Oberon, Ariel, Umbriel and Titania) are visible in a large backyard telescope. See our extensive article on hunting the moons of the solar system for more info, and the JPL/PDS rings node for corkscrew finder charts.

Uranus aug-dec moons oct12 — The path of Uranus, from late August through early December 2015. Inset: the position of the moons of Uranus on the evening of October 12th. Image credit: Starry Night Education software

The two outermost worlds have a fascinating entwined history. William Herschel discovered Uranus on the night of March 13^th, 1781. We can be thankful that the proposed name ‘George’ after William’s benefactor King George the III didn’t stick. Herschel initially thought he’d discovered a comet, until he followed the slow motion of Uranus over several nights and realized that it had to be something large orbiting at a great distance from the Sun. Keep in mind, Uranus and Neptune both crept onto star charts unnoticed pre-1781. Galileo even famously sketched Neptune near Jupiter in 1612! Early astronomers simply considered the classical solar system out to Saturn as complete, end of story.

And the hunt was on. Astronomers soon realized that Uranus wasn’t staying put: something farther still from the Sun was tugging at its orbit. Mathematician Urbain Le Verrier predicted the position of the unseen planet, and on and on the night of September 23^rd, 1846, astronomers at the Berlin observatory spied Neptune.

In a way, those early 19^th century astronomers were lucky. Neptune and Uranus had just passed each other during a close encounter in 1821. Otherwise, Neptune might’ve remained hidden for several more decades. The synodic period of the two planets—that is, the time it takes the planets to return to opposition—differ by about 2-3 days. The very first documented conjunction of Neptune and Uranus occurred back in 1993, and won’t occur again until 2164. Heck, In 2010, Neptune completed its first orbit since discovery!

To date, only one mission, Voyager 2, has given us a close-up look at Uranus and Neptune during brief flybys. The final planetary encounter for Voyager 2 occurred in late August in 1989, when the spacecraft passed 4,800 kilometres (3,000 miles) above the north pole of Neptune.

All thoughts to ponder as you hunt for the outer ice giants. Sure, they’re tiny dots, but as with many nighttime treats, the ‘wow’ factor comes with just what you’re seeing, and the amazing story behind it.

August 18, 2015September 23, 2016 by David Dickinson

Late Summer Tales of Tanabata

The August Milky Way graced with the occasional Perseid. Image credit: Andre van der Hoeven

One of the surest signs that late summer is here in the northern hemisphere is the arrival of the Milky Way in the early evening sky. As darkness falls ever earlier each night, the star-dappled plane of our home galaxy sits almost due south and stretches far to the north. This is also why we refer to the triangular shaped asterism formed by the bright stars of Altair, Deneb and Vega as the Summer Triangle. Two of these stars are the focus of a fascinating mythos from the Far East, and a poetic celestial configuration that commemorates star-crossed lovers lost.

We first heard of tales of Tanabata while stationed in Japan in the U.S. Air Force. Meaning ‘the seventh evening of the seventh month’ — sometimes simply abbreviated to ‘the seventh-seventh,’ — Tanabata is the summer Star Festival of Japan and dates back to about the 7^th century AD. Korean and Chinese cultures also have a version of the tale, and the festival that was once considered a rite for the elite gained popularity during the Edo period in the 17^th century to become a nationwide celebration.

Tanabata 2010. Wikimedia Commons/Hanasakijijii/3.0 license

The origin story of Tanabata involves the romance between the weaver’s daughter Orihime and the cow-herder’s son Kengyuu. As lovers will do, both began to neglect family duties — namely, weaving and cow-herding — until the two were separated by Orihime’s father, Tentei, represented by the Pole Star Polaris. The vast river of heaven, represented by the Milky Way, now separates the two. Orihime (Vega) sits on one side, while Kengyuu (Altair) is alone and unreachable on the other. The Emperor relented to Orihime’s pleading, however, and allows the two to meet once a year, on the seven day of the seventh month. And thus, Tanabata was born.

In late August, Vega and Altair are easily visible high to the east at dusk. You’re looking out along the Orion Spur — of which our solar system is a member — which traverses the Perseus and Cygnus arms of the galaxy beyond. We’re headed roughly in the same direction, towards a point known as the solar apex which is located near the bright star Vega, 25 light years distant. Remember the movie Contact? Vega was the fictional source of an extraterrestrial signal detected by Jodi Foster in the film.

our location in the Orion Spur of the Milky Way galaxy. image credit: Roberto Mura/Public Domain — You are here: our location in the Orion Spur of the Milky Way galaxy. Image credit: Roberto Mura/Public Domain

The modern Japanese calendar actually marks Tanabata on several different dates. The timing of the festival can vary from village to village, depending on which local convention is observed.

The original Japanese calendar was lunisolar, and very similar in convention to the modern Chinese festival calendar. A lunisolar calendar attempts to keep the cycles of the synodic period (29.5 days) of the Moon in sync with the solar calendar year, and must add an extra lunar month every 2-3 years to keep up. The modern Jewish calendar is another example of a lunisolar calendar, whereas the Islamic calendar follows the cycles of the Moon only.

The Summer Triangle. Image credit: Stellarium

Modern Japan has adapted the western Gregorian calendar, which is exclusively solar and reconciles the tropical and sidereal periods of the Sun. Though Tanabata was traditionally held in August, many Japanese communities simply transcribe the ‘seventh day of the seventh month’ onto the modern Gregorian calendar to mean July 7^th. Still other villages use the ‘one-month delay’ rule, to center Tanabata on August 7^th.

Some rural villages, however, still use the older lunisolar custom. By this reckoning, Tanabata always falls seven days after the New Moon at the end of seven full lunar cycles, when the Moon is a fat crescent not quite at first Quarter phase.

A table for future dates of Tanabata using the traditional lunisolar calendar for the next decade. Image credit: Dave Dickinson

In 2015, this happens this Thursday on August 20^th. Like Easter, Tanabata can fall early or late by about one lunar cycle, the earliest being August 1st, which happens on 2014 and 2033, and the latest being August 30th, which happens on 2006 and 2044.

Think of the crescent Moon as the boat, which once a year, brings the two lovers together across the celestial river of the Milky Way.

Late to the party? the waxing crescent Moon versus the plane of the galaxy on the evening of August 20th, 2015. Image credit: Starry Night Education Software (Click image to enlarge)

You may notice on the evening of the 20^th that the boat no longer makes its portage to the river, completing the scene. In fact, the cosmic lineup of the Milky Way and the fat waxing crescent Moon is now more of a September/October affair. What gives? Well, they once did align, way back when Tanabata first became a tradition over a millennia ago.

Blame our friend, the Precession of the Equinoxes for conspiring to keep our happy couple apart. The 26,000-odd year wobble is enough to move the equinoctial points about one degree along the ecliptic during a normal 70 year human life span. That all adds up, making the ferryman about one synodic period late to the party in modern times.

Enjoy the show, and happy Tanabata, whenever you may celebrate it in space and time.

August 13, 2015December 23, 2015 by Ken Kremer

Milestone Test Firing of NASA’s SLS Monster Rocket Engine Advances Human Path to Deep Space

During a 535-second test on August 13, 2015, operators ran the Space Launch System (SLS) RS-25 rocket engine through a series of tests at different power levels to collect engine performance data on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA
Story/imagery updated
See video below of full duration hot-fire test[/caption]

With today’s (Aug. 13) successful test firing of an RS-25 main stage engine for NASA’s Space Launch System (SLS) monster rocket currently under development, the program passed a key milestone advancing the agency on the path to propel astronauts back to deep space at the turn of the decade.

The 535 second long test firing of the RS-25 development engine was conducted on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi – and ran for the planned full duration of nearly 9 minutes, matching the time they will fire during an actual SLS launch.

All indications are that the hot fire test apparently went off without a hitch, on first look.

“We ran the full duration and met all test objectives,” said Steve Wofford, SLS engine manager, on NASA TV following today’s’ test firing.

“There were no anomalies.” – based on the initial look.

The RS-25 is actually an upgraded version of former space shuttle main engines that were used with a 100% success rate during NASA’s three decade-long Space Shuttle program to propel the now retired shuttle orbiters to low Earth orbit. Those same engines are now being modified for use by the SLS.

Spectators enjoy the view during the Aug. 13, 2015 test firing of the RS-25 engine for NASA’s Space Launch System (SLS) on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA — Spectators enjoy the view during the Aug. 13, 2015 test firing of the RS-25 engine for NASA’s Space Launch System (SLS) on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Credit: NASA

“Data collected on performance of the engine at the various power levels will aid in adapting the former space shuttle engines to the new SLS vehicle mission requirements, including development of an all-new engine controller and software,” according to NASA officials .

The engine controller functions as the “brain” of the engine, which checks engine status, maintains communication between the vehicle and the engine and relays commands back and forth.

The core stage (first stage) of the SLS will be powered by four RS-25 engines and a pair of the five-segment solid rocket boosters that will generate a combined 8.4 million pounds of liftoff thrust, making it the most powerful rocket the world has ever seen.

Since shuttle orbiters were equipped with three space shuttle main engines, the use of four RS-25s on the SLS represents another significant change that also required many modifications being thoroughly evaluated as well.

RS-25 test firing in progress on the A-1 test stand at NASA's Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015. Credit: NASA — RS-25 test firing in progress on the A-1 test stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi, on Aug. 13, 2015. Credit: NASA

The SLS will be some 10 percent more powerful than the Saturn V rockets that propelled astronauts to the Moon, including Neil Armstrong, the human to walk on the Moon during Apollo 11 in July 1969.

SLS will loft astronauts in the Orion capsule on missions back to the Moon by around 2021, to an asteroid around 2025 and then beyond on a ‘Journey to Mars’ in the 2030s – NASA’s overriding and agency wide goal.

Each of the RS-25’s engines generates some 500,000 pounds of thrust. They are fueled by cryogenic liquid hydrogen and liquid oxygen. For SLS they will be operating at 109% of power, compared to a routine usage of 104.5% during the shuttle era. They measure 14 feet tall and 8 feet in diameter.

They have to withstand and survive temperature extremes ranging from -423 degrees F to more than 6000 degrees F.

This video shows the full duration hot-fire test:

NASA has 16 of the RS-25s leftover from the shuttle era and they are all being modified and upgraded for use by the SLS rocket.

Today’s test was the sixth in a series of seven to qualify the modified engines to flight status. The engine ignited at 5:01 p.m. EDT and reached the full thrust level of 512,000 pounds within about 5 seconds.

The hot gas was exhausted out of the nozzle at 13 times the speed of sound.

Since the shuttle engines were designed and built over three decades ago, they are being modified where possible with state of the art components to enhance performance, functionality and ease of operation, by prime contractor Aerojet-Rocketdyne of Sacramento, California.

One of the key objectives of today’s engine firing and the entire hot fire series was to test the performance of a brand new engine controller assembled with modern manufacturing techniques.

“Operators on the A-1 Test Stand at Stennis are conducting the test series to qualify an all-new engine controller and put the upgraded former space shuttle main engines through the rigorous temperature and pressure conditions they will experience during a SLS mission,” says NASA.

“The new controller, or “brain,” for the engine, which monitors engine status and communicates between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle. The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine’s health and status.’

Video caption: RS-25 – The Ferrari of Rocket Engines explained. Credit: NASA

“The RS-25 is the most complicated rocket engine out there on the market, but that’s because it’s the Ferrari of rocket engines,” says Kathryn Crowe, RS-25 propulsion engineer.

“When you’re looking at designing a rocket engine, there are several different ways you can optimize it. You can optimize it through increasing its thrust, increasing the weight to thrust ratio, or increasing its overall efficiency and how it consumes your propellant. With this engine, they maximized all three.”

Engineers will now pour over the data collected from hundreds of data channels in great detail to thoroughly analyze the test results. They will incorporate any findings into future test firings of the RS-25s.

NASA says that testing of RS-25 flight engines is set to start later this fall.

“The RS-25 engine gives SLS a proven, high performance, affordable main propulsion system for deep space exploration. It is one of the most experienced large rocket engines in the world, with more than a million seconds of ground test and flight operations time.”

NASA plans to buy completely new sets of RS-25 engines from Aerojet-Rocketdyne taking full advantage of technological advances and modern manufacturing techniques as well as lessons learned from this hot fire series of engine tests.

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.

Artist concept of the SLS Block 1 configuration. Credit: NASA

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.

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

Ken Kremer

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

STS-135: Last launch using RS-25 engines that will now power NASA’s SLS deep space exploration rocket. NASA’s 135th and final shuttle mission takes flight on July 8, 2011 at 11:29 a.m. from the Kennedy Space Center in Florida bound for the ISS and the high frontier with Chris Ferguson as Space Shuttle Commander. Credit: Ken Kremer/kenkremer.com

August 12, 2015December 23, 2015 by David Dickinson

Revealed: Mars to Appear Larger Than a Full Moon!

A recipe for a three ring circus? Image credit:

We can finally reveal the truth.

A massive conspiracy, spanning over a decade, has been revealed at last by basement bloggers, YouTubers and Facebook users everywhere, implicating ‘big-NASA’ and the powers that be in a massive cover-up.

Yes, it’s the month of August once again, and the Red Planet Mars is set to appear ‘larger than a Full Moon’ over the skies of Earth, as it apparently does now… every year.

Um, no. Stop. Just… stop.

Sure, by now, you’ve had the hoax forwarded to you by that certain well-meaning, but astronomically uninformed family member/co-worker/anonymous person on Facebook.

What’s new under the Sun concerning the August Mars Hoax? To see where the hoax was born, we have to journey all the way back to the close opposition of Mars on August 27^th, 2003. Hey, we actually took two weeks leave in the Fall of 2003 just to sketch and image Mars each night from our backyard lair in the Sonoran desert south of Tucson, Arizona from the then known Very Small Optical Observatory. Those were the days. We measured dial-up internet speeds in kbit/s, ‘burned CDs,’ and Facebook and Twitter were still some years away. Even spam e-mail was still sorta hip.

Two years later in 2005, we were all amused, as the ‘August Mars Hoax’ chain email made its first post-2003 appearance in our collective inboxes. Heck, we were even eager in those halcyon days to take to the nascent web, and do that new hipster thing known as ‘blogging’ to explain just exactly why this couldn’t be so to the masses.

Later in 2006, 2007, and 2008, it wasn’t so funny.

The Mars Hoax just wouldn’t die. “One more unto the breach,” the collective astro-blogging community sighed, as we all dusted off last year’s post explaining how the Red Planet could never approach our own fair world so closely.

It. Just. Couldn’t. Because orbital mechanics. Because physics.

Even the advent of social media couldn’t kill in annual onslaught of the Mars Hoax, and over a Spiderman movie reboot later, we’re now seeing it shared across Facebook, Twitter and more.

Sure, the Mars Hoax is as fake as Donald Trump’s hair. If there’s any true science lesson to learn here, it’s perhaps the mildly interesting social science study of just how the Mars hoax weathers the lean months of winter, to reemerge every August.

Here’s the skinny (again!) on just why Mars can’t appear as large as the Full Moon:

-The Moon is 3,474 kilometers in diameter, and orbits the Earth at an average distance of just under 400,000 kilometers.

-At this distance, the Moon can only appear about 30’ (half a degree) across.

-Think that’s a lot? Well, you could ring the 360 degree circle of the local horizon with 720 Full Moons.

-Mars, like the Earth, orbits the Sun. Even with Earth at aphelion (its most distant point) and Mars at perihelion, we’re still 206.7 – 151.9 = 54.8 million km apart. Sure, aphelion and perihelion of our respective worlds don’t quite line up in our current epochs, but we’ll indulge imagination and fudge things a bit.

-Though Mars is just over 2x times larger in diameter than the Moon, it’s also more than 143 times farther away, even at its said hypothetical closest.

Credit Dave Dickinson — Mars vs Earth; oppositions from 2003 to 2018, including perihelion and aphelion positions. Image credit: Dave Dickinson

-Still want to see Mars as big as a Full Moon? Perhaps one day, astronauts will, though they’ll have to be orbiting just over a 800,000 km from the Red Planet to do it.

If we sound a little pessimistic in our characterizing the Mars Hoax as a recurring non-story, it’s because we see many truly fantastic things in space news that get far from their far shake. Real stories, of collapsing stars, rogue exoplanets, and intrepid rovers exploring distant worlds. Tales of humanoids, exploring space and doing the very best and noble things humanoids as a species can do.

Want to trace the history the Mars Hoax?

Here’s the saga of Universe Today’s coverage of all things ‘Mars Hoax’ since those olden days of the early web:

2005- No, Mars Won’t Look as Big as the Moon

2006- No, Mars Won’t Look as Big as the Moon in August

2007- Will Mars Look as Big as the Moon on August 27? Nope

2008- Please (Again) – Mars Will NOT Look as Big as the Full Moon

2009- Mars Will NOT Look as Big as the Full Moon… But You Can Watch it Get Closer

2010- Tonight’s the Night Mars Will NOT Look as Big as the Full Moon

2011- Is the Moon Mars Myth Over?

2013- The Cyber Myth that Just Won’t Die

2016- ????

Hey, it looks like the hoax did take a break in 2012 and 2014, so that’s encouraging at least…

The great Mars opposition of 2003. image credit: Dave Dickinson — The great Mars opposition of 2003. Image credit: Dave Dickinson

Now, I’m going to do my best to truly terrify all of science blogger-dom, and leave you with one final thought to consider. Mars reaches opposition (otherwise known in astronomical circles as ‘when it’s really nearest to the Earth’) once roughly every 26 months. All oppositions of Mars are not created equal, owing mostly to the eccentric orbit of the Red Planet. We have another fine opposition of Mars coming right up next year on May 22^nd, 2016, followed by one that’s very nearly as favorable as the historic 2003 opposition in 2018, falling juuuuust shy of August on July 28^th of that year…

Will the Mars Hoax meme find a new unwitting audience, and with it, new life?

Sleep tight…. we’ll be covering real science stories in the meantime, ’til we’re called to do battle with the Mars Hoax once again.

August 11, 2015December 23, 2015 by David Dickinson

A Thrift Store Find Yields an Astronomical Mystery

A good mystery is often where you find it. Photographer Meagan Abell recently made a discovery during a thrift store expedition that not only set the internet abuzz, but also contains an interesting astronomical dimension as well. This is an instance where observational astronomy may play a key role in pinning down a date, and we’d like to put this story before the Universe Today community for further insight and consideration.

Meagan first discovered the set of four medium format negatives at a thrift store on Hull Street in Richmond, Virginia. Beyond that, they have no provenance. Meagan was amazed at what see saw when she scanned in the negatives: the images of a woman walking into the surf have an ethereal beauty all their own. Obviously the work of a skilled photographer, the photos appear to date from the late 1940s or 1950s.

Meagan turned to social media for help, and cyber-sleuths responded in a big way. #FindTheGirlsOnTheNegatives became a viral hit, but thus far, who the women in the images are and the story behind them remains a mystery.

We do know one tantalizing bit of information: several Facebook users have pinned down the location as Dockweiler Beach, California near Los Angeles International Airport. Keen-eyed observers noted the similarity of the outline of the distant hills seen to the north in one of the images.

A few things caught our eye upon reading the mystery of the girls in the negatives this past weekend. One shot clearly shows the notch of the Sun just below the twilight horizon. A second, even more intriguing image shows a tiny sliver of Moon just to the subject’s upper left.

Could a date, or set of dates, be estimated based on these factors alone?

Let’s slip into astro-detective mode now. A few things are obvious right off the bat. First, the Moon is a waxing crescent, meaning the shots would have to be set in the evening. This also lends credence to the ocean being the Pacific, because the sunset is occurring over water. The similarity in cloud formations across all of the images seen also strongly suggests the photographer took all of the pictures on the same evening, during one session.

Can that crescent Moon tell us anything? It’s tiny and indistinct, but we have a few things to go on. The Moon looks to be a 5-6 day old waxing crescent about 30-40% illuminated. Not all waxing crescent Moons are created equal, as the ‘horns of the Moon’ can point in various directions based on the angle of the ecliptic to the local horizon at different times of the year.

A typical sampling of the orientation of the horns of the waxing crescent Moon throughout the year as seen from latitude 34 degrees north. Image credit: Dave Dickinson

The horns of the Moon appear to be oriented about 35 degrees from horizontal. Assuming the subject in the red dress is elevated slightly and about 20 feet from the observer, the Moon would be about 25-30 degrees above the horizon in the shot.

Now, Dockweiler Beach is located at latitude 33 degrees 55’ 20” north, longitude 118 degrees 26’ 3” west. The beach itself faces a perpendicular azimuth of 240 degrees out to sea, or roughly WSW.

Already, we can rule out winter and spring, because of the unfavorable angle of the dusk ecliptic. We want a time of year with A) a shallow southward ecliptic and B) a sunset roughly due west.

Turns out, late July through early October fit these ideal conditions for the location.

Can we narrow this even further? Well, here’s one possibility. Remember, this next step is what gumshoe PIs call a ‘hunch’…

The motion of the Moon is a wonderfully complicated affair. The path of the Moon is inclined about five degrees relative to the ecliptic, meaning that the Moon can ride anywhere from declination 28 degrees south, to 28 degrees north. From latitude 34 degrees north, this puts the mid-July ecliptic at about 33 degrees elevation across the meridian at sunset.

The nodal points where the path of the Moon crosses the ecliptic also precess slowly around the celestial sphere. This motion completes one revolution every 18.6 years, meaning that the Moon reaches those maximum declination values (sometimes referred to as a ‘long nights’ or the Major Lunar Standstill of the Moon) just under once every 19 years.

This occurred last in 2006, and will occur next in 2025. Incidentally, we’re at a shallow mid-point (known as a Minor Lunar Standstill) between the two dates this coming Fall.

A good fit? A comparison of the Moon in the image (left) with a simulated view in Stellarium from August 19th, 1950 (click to enlarge). Image credit: Dave Dickinson/Meagan Abell

This also puts the late summer 1^st quarter Moon as far south ‘in the weeds’ as possible. Extrapolating back in time, this sort of wide-ranging Moon occurred around 1949. Looking at the celestial scene in Stellarium, three dates nail the horn angle and elevation of the Moon seen in the photograph pretty closely around this time:

-August 11^th, 1948

-August 29^th, 1949

-August 19^th, 1950

Of course, this is just a hunch. Perhaps the subject was standing on a westward facing spit of rocks. Or maybe the photographer was closer or farther away than estimated. Or maybe the negative was inverted left to right along the way… that’s why I’d like to invite, you, the astute sky watcher, to weigh in.

And even if we pinned down the date, the mystery remains. Who are the girls in the negatives? What became of the photo shoot? And how did the negatives end up in a thrift store in Virginia?

Read another astronomical mystery sleuthed out by Dave Dickinson, with The Downing of Spirit ‘03: Did the Moon Play a Role?

Update: an sharp-eyed reader noticed that if you boost the contrast, you can see an additional ‘speck’ in the Moon image (see comment discussion below):

Update: Meagan responds: “The object along the horizon in the crescent Moon image is actually just a transparency defect.” A second image from the same strip does not show the white speck (arrowed above) near the horizon.

August 5, 2015December 23, 2015 by Ken Kremer

Moon Transits Earth in Eye-poppingly EPIC View from 1 Million Miles Away

This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA
See YouTube version and EPIC camera below[/caption]

An eye-poppingly ‘EPIC’ view of the sunlit far side of the Moon transiting the sunlit side of Earth was recently captured by NASA’s Earth Polychromatic Imaging Camera (EPIC) camera from one million miles away. “Wow!” – is an understatement!

The stunning animation of the Moon crossing in front of the Earth, shown above, and seemingly unlike anything else, was created from a series of images taken in July by NASA’s EPIC camera flying aboard the orbiting Deep Space Climate Observatory (DSCOVR), a space weather monitoring satellite, according to a NASA statement.

Have just witnessed NASA’s New Horizons flyby of the Pluto-Charon double planet system, the similarity to what some call the Earth-Moon double planet system is eerie. You could imagine ones heart going out to Earth’s Australian continent as an upside down version of Pluto’s bright heart shaped ‘Tombaugh Regio’ region in the southern hemisphere.

EPIC is a four megapixel CCD camera and telescope mounted on DSCOVR and orbiting at the L1 Lagrange Point – a neutral gravity point that lies on the direct line between Earth and the sun.

The goal of the $340 million DSCOVR is to monitor the solar wind and aid very important forecasts of space weather at Earth from L1.

EPIC will capture “a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere.”

L1 is located 1.5 million kilometers (932,000 miles) sunward from Earth. At L1 the gravity between the sun and Earth is perfectly balanced and the DSCOVR satellite orbits about that spot just like a planet.

The EPIC images “were taken between 3:50 p.m. and 8:45 p.m. EDT on July 16, showing the moon moving over the Pacific Ocean near North America,” NASA said.

This image shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credits: NASA/NOAA — This image shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credits: NASA/NOAA

You can see Earth’s North Pole at the upper left side of the images which results from the orbital tilt of Earth from the vantage point of the spacecraft at the L1 Lagrange Point.

EPIC will take full disk color images of the sunlit side of Earth at least six times per day.

They will be made publically available by NASA at a dedicated website, when the camera starts its regular daily science observation campaign of the home planet in about a month during September.

NASA says the images will show varying views of the rotating Earth and they will be posted online some 12 to 36 hours after they are acquired.

Each image is actually a composite of three images taken in the red, green and blue channels of the EPIC camera to provide the final “natural color” image of Earth. Since the images are taken about 30 seconds apart as the moon is moving there is a slight but noticeable artifact on the right side of the moon, NASA explained.

Altogether, “ EPIC takes a series of 10 images using different narrowband spectral filters — from ultraviolet to near infrared — to produce a variety of science products. The red, green and blue channel images are used in these color images.”

EPIC should capture these Earth-Moon transits about twice per year as the orbit of DSCOVR crosses the orbital plane of the moon.

The closest analog according to NASA came in May 2008 when NASA’s Deep Impact spacecraft “captured a similar view of Earth and the moon from a distance of 31 million miles away. The series of images showed the moon passing in front of our home planet when it was only partially illuminated by the sun.”

We never see the far side of the moon from Earth since the bodies are tidally locked. And its quite apparent from the images, that the moon’s far side looks completely different from the side facing Earth. The far side lacks the large, dark, basaltic plains, or maria, that are so prominent on the Earth-facing side.

“It is surprising how much brighter Earth is than the moon,” said Adam Szabo, DSCOVR project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.

“Our planet is a truly brilliant object in dark space compared to the lunar surface.”

DSCOVR is a joint mission between NOAA, NASA, and the U.S Air Force (USAF) that is managed by NOAA. The satellite and science instruments were provided by NASA and NOAA.

Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com/AmericaSpace — Technician works on NASA Earth science instruments and Earth imaging EPIC camera (white circle) housed on NOAA/NASA Deep Space Climate Observatory (DSCOVR) inside NASA Goddard Space Flight Center clean room in November 2014. Credit: Ken Kremer/kenkremer.com

The couch sized probe was launched atop a SpaceX Falcon 9 on Feb. 11, 2015 from Cape Canaveral, Florida, to start a million mile journey to its deep space observation post. The rocket was funded by the USAF.

DSCOVR was first proposed in 1998 by then US Vice President Al Gore as the low cost ‘Triana’ satellite to take near continuous views of the Earth’s entire globe to feed to the internet as a means of motivating students to study math and science. It was eventually built as a much more capable Earth science satellite that would also conduct the space weather observations.

But Triana was shelved for purely partisan political reasons and the satellite was placed into storage at NASA Goddard and the science was lost until now.

It was also dubbed “Goresat.’

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

Ken Kremer

Video caption: This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft’s Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth – one million miles away. Credit: NASA/NOAA