Why is Tonight’s Full Moon the Smallest of the Year?

Moon at Perigee and Apogee. Credit NASA

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Think we can only see half of the Moon’s surface from Earth? Not always.

Over the course of the year, observers on Earth can view a bit less and a bit more than half of the lunar surface. Additionally, the Moon appears smaller in the sky during some months compared to other times of the year.

Due to the processes at work, tonight’s full Moon is an opposite of the “Supermoon” that made headlines earlier this year.

What causes our Moon to change apparent size throughout the year, and how do we notice this phenomenon?

While it would be difficult to judge the apparent size of the full Moon each month with our eyes, the phenomenon of Lunar librations is readily apparent in the animation below.

There are three forces at work that help produce the “dancing” effect as shown in the video above.

There are three types of lunar libration:

First, the Moon doesn’t orbit Earth in a perfectly circular orbit. An eccentric orbit will cause our Moon to lead and lag in its orbital position while its rotational speed stays the same. This causes a libration in longitude.

Secondly, the Moon’s rotational axis is slightly inclined to its orbital plane, with respect to Earth. The Moon’s orbit is also inclined with respect to the ecliptic, allowing the Moon to be illuminated from above and sometimes from below. The illumination from above and below allows some of the lunar surface beyond the poles to be visible from Earth.

Last but not least, there is a small daily oscillation due to Earth’s rotation. This oscillation changes the perspective at which an observer views the Moon. Imagine a straight line connecting the center of Earth with the center of the Moon. Over time an observer would be on one side of this imaginary line and then the other, which would allow the observer to look first around one side of the Moon and then around the other. This is because an observer on Earth is on the surface and not at the center of Earth.

A slight bit of Lunar trivia: Lunar librations helped notable British astronomer Patrick Moore investigate the edge regions where librations provided extra coverage. Moore’s investigations lead him to discover a large circular feature, which he named “Mare Oriental”. Once studies of the Lunar farside were performed from space, it was discovered that Mare Oriental was a lava filled impact crater.

LROC “Treasure Map” Reveals Titanium Deposits

LROC WAC mosaic showing boundary between Mare Serenitatis and Mare Tranquillitatis. The relative blue colour of the Tranquillitatis mare is due to higher abundances of the titanium bearing mineral ilmenite. Image Credit: NASA/GSFC/Arizona State University

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At a joint meeting of the European Planetary Science Congress and the American Astronomical Society’s Division for Planetary Sciences, Mark Robinson and Brett Denevi have unveiled a map of the Moon combining observations in visible and ultraviolet wavelengths showing areas rich in Titanium ores. This discovery not only provides a potential source of a valuable metal, but also provides valuable information which will help scientists better understand lunar formation and composition of the Moon’s interior.

How did Robinson and Denevi create this map, and what can other scientists learn from this new data?

“Looking up at the Moon, its surface appears painted with shades of grey – at least to the human eye. But with the right instruments, the Moon can appear colourful,” said Robinson, (Arizona State University). “The maria appear reddish in some places and blue in others. Although subtle, these colour variations tell us important things about the chemistry and evolution of the lunar surface. They indicate the titanium and iron abundance, as well as the maturity of a lunar soil.”

Robinson and the LROC team previously used similar methods with Hubble Space Telescope images to map titanium abundances near the Apollo 17 landing site, which had varying titanium levels. When Robinson compared the Apollo data with the HST images, it was revealed that titanium levels corresponded to the ratio of ultraviolet to visible light reflected by the lunar surface.

“Our challenge was to find out whether the technique would work across broad areas, or whether there was something special about the Apollo 17 area,” said Robinson. Using nearly 4000 images from the LRO Wide-Area Camera (WAC), Robinson’s team created a mosaic image, which was then studied using the techniques developed with the Hubble imagery. The research used the same ultraviolet to visible light ratio to deduce titanium abundance, which was verified by surface samples gathered by Apollo and Luna missions.

“We still don’t really understand why we find much higher abundances of titanium on the Moon compared to similar types of rocks on Earth. What the lunar titanium-richness does tell us is that the interior of the Moon had less oxygen when it was formed, knowledge that geochemists value for understanding the evolution of the Moon,” added Robinson.

On our Moon, titanium is found in a mineral known as ilmenite, which contains iron, titanium and oxygen. In theory, Lunar miners could process ilmenite to separate the iron, titanium and oxygen. Aside from the elements present in ilmenite, Apollo data shows that minerals containing titanium can retaining particles from the solar wind, such as helium and hydrogen. Future inhabitants of the Moon would find helium and hydrogen, along with oxygen and iron to be vital resources.

“The new map is a valuable tool for lunar exploration planning. Astronauts will want to visit places with both high scientific value and a high potential for resources that can be used to support exploration activities. Areas with high titanium provide both – a pathway to understanding the interior of the Moon and potential mining resources,” said Denevi (John Hopkins University).

The new maps also provide insight into how lunar surface materials are altered by the impact of charged particles from the solar wind and high-velocity micrometeorite impacts. Over time, lunar rock is pulverized into a fine powder by micrometeorite impacts, and charged particles alter the chemical composition and color of the surface.Recently exposed materials, such as ejecta from impacts appear bluer and have higher reflectivity than older Lunar regolith (soil). Younger material is estimated to take about half a billion years to fully “weather” to the point where it would blend in with older material.

“One of the exciting discoveries we’ve made is that the effects of weathering show up much more quickly in ultraviolet than in visible or infrared wavelengths. In the LROC ultraviolet mosaics, even craters that we thought were very young appear relatively mature. Only small, very recently formed craters show up as fresh regolith exposed on the surface,” said Robinson.

So it seems there’s always something new to be learned from our Moon. Coincidentally, tomorrow (October 8th) is International Observe the Moon Night, so make sure you grab your binoculars or telescope tomorrow night and do some lunar observations! Be sure to check out our previous coverage of International Observe the Moon Night by our Senior Editor, Nancy Atkinson at: http://www.universetoday.com/89522/need-an-excuse-to-gaze-at-the-moon-international-observe-the-moon-night-is-coming/

If you’d like to learn more about the Lunar Reconnaissance Orbiter Camera, visit: http://lroc.sese.asu.edu/

Source: Europlanet Research Infrastructure / Division for Planetary Sciences of the American Astronomical Society Joint Press Release

Need an Excuse to Gaze at the Moon? International Observe the Moon Night is Coming!

This photo of the Moon was taken on October 2, 2011 in Angera, Lombardy, IT. Credit: Milo. Click image to see on Flickr.
This photo of the Moon was taken on October 2, 2011 in Angera, Lombardy, IT. Credit: Milo.

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Most of us space-minded folks don’t need an excuse to gaze upon the brightest object in the night sky – our own Moon. But just in case you need a reason or are hoping to convince some friends or family to take a look with you, there’s a special event coming up that encourages more people to take the time to take a gander at our closest and constant companion in space. Saturday, October 8, 2011 is the second annual International Observe the Moon Night (InOMN). Across the country and around the world, astronomy clubs, museums, observatories, parks, and schools will hold special events to introduce the public to the Moon. There will be telescopes to look through, activities to join, and presentations from experts in lunar science will be streamed to participating event locations.

“There will hundreds of events world-wide that will share the excitement of lunar science and explorations” said Brian Day, from the NASA Lunar Science Institute, who is one of the organizers of the event.

This photo of the Moon was taken on October 4, 2011. Credit: Amar Mainkar. Click to see the image on Flickr.

In a podcast for 365 Days of Astronomy and NLSI, Day said that right now an especially exciting time to engage the public in the Moon. (Listen to the podcast here.) A new generation of robotic probes has brought about a revolution in our understanding of our nearest neighbor in space. Our long-held view of a non-changing and dry Moon is now being replaced with an appreciation for the Moon as a dynamic body with significant deposits of water ice, a fascinating history, and a thin atmosphere that may play a role in a potential lunar water cycle. “It is indeed a New Moon!” Day said.

There’s excitement on the amateur front, as well. “Recent developments in technology have allowed amateur astronomers to image the Moon in detail that previously was only attainable from orbiting spacecraft,” Day said. “The work that they are doing and the imagery they are getting is just fantastic So, this is a great time to appreciate what is happening with the Moon on both the amateur and professional communities.”

(Thanks to amateur astronomers who have uploaded images to Universe Today’s Flickr group — the images included in this article are courtesy of Milo, Amar Mainkar and Marcopic3000.)

The overall goal for InOMN is to engage lunar science and education communities, amateur astronomers, space enthusiasts, and the general public in what has become an annual lunar observation campaign.

“The Moon will be at a favorable phase, and we are going to be able to see some really magnificent features,” Day said, “so it is a good time to show up at an International Observe the Moon Night event and take a look at what is happening in the sky.”

This image of the Moon was taken on Oct. 5, 2011. Credit: Marcopic3000. Click on image to see it on Flickr.

This year’s InOMN may provide a bit of an extra show in Europe and Northern Asia, as it is occurring on the night of the maximum of the Draconid meteor shower.

For more information and to find an InOMN event near you or to learn how to conduct your own InOMN event, visit http://www.observethemoonnight.org. The website includes information on events around the world, activities and downloadable information to allow you to host your own event, and much more.

Want to get your astrophoto featured on Universe Today? Join our Flickr group, post in our Forum or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Student Alert: GRAIL Naming Contest – Essay Deadline November 11

NASA announces student Essay Naming Contest for the twin GRAIL Lunar spaceships. The essay writing contest is open to students in Grades K - 12 at schools in the United States. Submission Deadline is November 11, 2011. GRAIL A & B are twin science robots that will explore the gravity field of the moon like never before.

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Student Alert ! – Here’s your once in a lifetime chance to name Two NASA robots speeding at this moment to the Moon on a super science mission to map the lunar gravity field. They were successfully launched from the Earth to the Moon on September 10, 2011. Right now the robots are called GRAIL A and GRAIL B. But, they need real names that inspire. And they need those names real soon. The goal is to “capture the spirit and excitement of lunar exploration”, says NASA – the US Space Agency.

NASA needs your help and has just announced an essay writing contest open to students in Grades K – 12 at schools in the United States. The deadline to submit your essay is November 11, 2011. GRAIL stands for “Gravity Recovery And Interior Laboratory.”

The rules state you need to pick two names and explain your choices in 500 words or less in English. Your essay can be any length up to 500 words – even as short as a paragraph. But, DO NOT write more than 500 words or your entry will be automatically disqualified.

Learn more about the GRAIL Essay Naming Contest here:

Read all the Official Contest Rules here:

Download the Naming Contest Submission Form here:

Students: NASA Wants You to Name that GRAIL !
Write an Essay and name these twin Lunar mapping satellites. NASA’s twin GRAIL A & B science probes are now streaking to the Moon and arrive on New Year’s Day 2012. This picture shows how they looked, mounted side by side, during launch preparations prior to blasting off for the Moon on Sept. 10, 2011 from Florida. Credit: Ken Kremer

The GRAIL A and B lunar spaceships are twins – just like those other awe inspiring robots “Spirit” and “Opportunity” , which were named by a 10 year old girl student and quickly became famous worldwide and forever because of their exciting science missions of Exploration and Discovery.They arrive in Lunar Orbit on New Year’s Day 2012.

Blastoff of twin GRAIL A and B lunar gravity mapping spacecraft on a Delta II Heavy rocket on Sept. 10 from Pad 17B Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT. Credit: Ken Kremer

And there is another way that students can get involved in NASA’s GRAIL mission.

GRAIL A & B are both equipped with four student-run MoonKAM cameras. Students can suggest targets for the cameras. Then the cameras will take close-up views of the lunar surface, taking tens of thousands of images and sending them back to Earth.

“Over 1100 middle schools have signed up to participate in the MoonKAM education and public outreach program to take images and engage in exploration,” said Prof. Maria Zuber of MIT.

Prof. Zuber is the top scientist on the mission and she was very excited to announce the GRAIL Essay Naming contest right after the twin spaceships blasted off to the Moon on Sep 10, 2011 from Cape Canaveral in Florida.

What is the purpose of GRAIL ?

“GRAIL simply put, is a ‘Journey to the Center of the Moon’,” says Dr. Ed Weiler, NASA Associate Administrator of the Science Mission Directorate in Washington, DC.

“It will probe the interior of the moon and map its gravity field by 100 to 1000 times better than ever before. We will learn more about the interior of the moon with GRAIL than all previous lunar missions combined. Precisely knowing what the gravity fields are will be critical in helping to land future human and robotic spacecraft. The moon is not very uniform. So it’s a dicey thing to fly orbits around the moon.”

“There have been many missions that have gone to the moon, orbited the moon, landed on the moon, brought back samples of the moon,” said Zuber. “But the missing piece of the puzzle in trying to understand the moon is what the deep interior is like.”

So, what are you waiting for.

Start thinking and writing. Students – You can be space explorers too !

Read Ken’s continuing features about GRAIL
GRAIL Lunar Blastoff Gallery
GRAIL Twins Awesome Launch Videos – A Journey to the Center of the Moon
NASA launches Twin Lunar Probes to Unravel Moons Core
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

How Can You See the Sun and the Moon at the Same Time?

A daytime Moon over New Zealand in August 2010. Credit: NASA/Phil Davis

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Did you know that you can see the Moon during the day?

Many people only notice our Moon at night, when there is considerably more contrast between the Moon and the night sky. Being the second brightest object in the sky (after the Sun, of course) and with Venus visible during the day to trained eyes, it’s no real surprise that the Moon is visible during the day.

Why then, do so many people act surprised when they notice the Moon during the day? What makes it possible for the Moon to be visible during the day?

Understanding how and when you can spot the Moon is a matter of knowing the different lunar phases, specifically the relationship between the Sun, Earth and the Moon during each phase. The image below shows the simple geometry responsible for each of the Moon’s distinct phases.

In the diagram it’s pretty easy to see that when Earth is between the Sun and the Moon, we see a full moon. When the Moon is between Earth and the Sun, we see a new Moon. The other phases are simply transitions from new to full and from full back to new.

Schedule of Moon Phases. Times shown indicate when the moon is overhead.
Schedule of Moon Phases. Times shown indicate when the moon is overhead.

Based on the orbital geometry of the Moon, there will certainly be times where the Sun will partially illuminate the Moon, during the day and at night. What makes the lunar cycle even more interesting is that the moon rises about an hour later each day, and yet invariably, a full moon rises near dusk and sets near sunrise. The reverse is true in that a new moon rises near sunrise and sets near dusk.

Looking at the above diagram though, a question comes to mind…
Why don’t we have a lunar eclipse during each full moon, or a solar eclipse each new moon?

I’ll explain the conditions needed for a solar or lunar eclipse in an upcoming article.

In the meantime enjoy the transition from waning gibbous to waning crescent over the next week and get your telescopes out during the weekend of the 25th. The Moon will almost be at its new phase.

If you’d like to learn more about moon phases and when the moon will be visible in your area, the US Naval observatory has a great calculator at: http://aa.usno.navy.mil/data/docs/RS_OneYear.php

GRAIL Lunar Blastoff Gallery

GRAIL Lunar gravity mappers rocket to the moon atop a Delta II Heavy booster on Sept. 10 from Cape Canaveral, Florida. Credit: Alan Walters (awaltersphoto.com)

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Check out our gallery of more thrilling launch photos of NASA’s twin GRAIL spacecraft departing Earth on Saturday, Sept. 10 at 9:08 a.m. EDT from Pad 17B at Cape Canaveral Air Force Station in Florida.

Although GRAIL’s liftoff was delayed a few days by excessively high upper level winds, it was well worth the wait and put on a spectacular show as the booster thundered away from Space Launch Complex 17. This Delta II rocket was almost certainly the last ever Delta to blastf off from the Florida Space Coast.

Blastoff of Delta II Heavy rocket and twin spacecraft on Sept. 10 from Pad 17B at Cape Canaveral at 9:08 a.m. EDT. View from Press Site 1. Credit: Alan Walters (awaltersphoto.com)

The GRAIL spacecraft continue to function well at the start of their nearly four month journey to the Moon wher they will map the moon gravity in unprecedented detail and provide new insight into the formation and evolution of the rocky bodies of the inner Solar System.

Sept. 10 Blastoff of Delta II and GRAIL gravity mappers. Credit: Ken Kremer (kenkremer.com)
Sept. 10 Blastoff of Delta II and GRAIL gravity mappers. Credit: Alan Walters (awaltersphoto.com)
Sept. 10 Blastoff of Delta II and GRAIL gravity mappers. Credit: Ken Kremer (kenkremer.com)
Sept. 10 Blastoff of Delta II and NASA’s GRAIL spacecraft. Credit: Alan Walters (awaltersphoto.com)
Sept. 10 Blastoff of Delta II and GRAIL gravity mappers. Credit: Ken Kremer
Credit: Alan Walters (awaltersphoto.com)
Credit: Alan Walters (awaltersphoto.com)
Credit: Alan Walters (awaltersphoto.com)
Credit: Alan Walters (awaltersphoto.com)
Credit: Alan Walters (awaltersphoto.com)
GRAIL and Delta II rocket soar to space on Sept 10 from Pad 17B at Cape Canaveral, Florida. Credit: Ken Kremer (kenkremer.com)

NASA GRAIL Launch Images

Read Ken’s continuing features about GRAIL
GRAIL Twins Awesome Launch Videos – A Journey to the Center of the Moon
NASA launches Twin Lunar Probes to Unravel Moons Core
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

GRAIL Twins Awesome Launch Videos – A Journey to the Center of the Moon

GRAIL A and B Lunar gravity mappers rocket to the moon atop a Delta II Heavy booster on Sept. 10 from Cape Canaveral, Florida. View from Press Site 1. Credit: Alan Walters (awaltersphoto.com)

Video caption: NASA’s twin GRAIL spacecraft blast off atop a Delta II Heavy booster at 9:08 a.m. EDT on Saturday, September 10, 2011 from Cape Canaveral, Florida, on a mission to explore the moon in unprecedented detail.

Be sure to check out these awesome launch videos showing the Delta II Heavy rocket blasting off with NASA’s GRAIL Lunar Gravity Mapper twins on a “Journey to the Center of the Moon” – as shot by NASA and others – on Sept. 10. from Pad 17 B at Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT.

Thus began a circuitous 3.5 month voyage from the Earth to the Moon culminating in lunar orbit arrival on New Year’s Eve and Day 2012.

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Liftoff of the $496 Million Gravity Recovery and Interior Laboratory (GRAIL) duo marked the last currently scheduled launch of a United Launch Alliance Delta II from Florida and also the last launch from Space Launch Complex 17. This was the 356th Delta launch overall since the first one in 1960. It was the 110th and final planned flight of a Delta II from Florida.

Watch the NASA GRAIL Launch Video as the 12 story Delta’s 1st stage liquid and solid engines ignite and the rocket’s explosive exhaust and fiery flames instantaneously and dramatically shoot out from below and are vented safely to the side through specially constructed flame ducts to protect the rocket.

Just after the 1 minute mark, the 6 ground lit solid rocket motors are jettisoned and dramatically tumble away from the first stage. Moment later comes the ignition of the three air-lit solid rocket motors.

This dramatic video was shot by Matt Travis of spacearium -from my viewing location with a hoard of photojournalists at Press Site 1 located inside Cape Canaveral Air Force Station.

Press Site 1 is just 1.5 miles away from Pad 17B. It offers the closest and best view of the mighty Delta II rocket which stands 128 feet tall and generates some 1.3 million pounds of liftoff thrust.

Watch this video for post-launch commentary from NASA’s Delta II Launch manager Tim Dunn from the Mission Director’s Center.

Dawn launch on September 27, 2007 by a Delta II Heavy rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

The GRAIL Launch video below was taken from Jetty Park Pier, about 2.9 miles south of Pad 17B and shows a completely different perspective from across the waterway of Port Canaveral.

I watched the unforgettable launch of Dawn five years ago from Jetty Park Pier.

Jetty Park and the beaches along Cape Banaveral and Cocoa Beach have been the best place for the public to view Delta rocket launches.


Thousands of spectators lining the Florida Space Coast were absolutely thrilled to witness the historic launch of GRAIL on the final Delta II booster from Florida on a gorgeous morning.

GRAIL’s primary science objectives during the 82 day mission are to determine the structure of the lunar interior, from crust to core, and to advance understanding of the thermal evolution of the moon and apply that to the other rocky bodies in our solar system.

Check this short NewBlast Video summary of GRAIL’s launch and objectives from Spaceflight Now

Many of NASA’s recent science missions have launched aboard Delta II rockets, including the outstandingly successful Spirit and Opportunity Mars rovers, Dawn Asteroid Orbiter, MESSENGER Mercury orbiter and Stardust and Deep Impact comet spacecraft.

Congratulations to everyone on the GRAIL team for a superb performance !

GRAIL A and B Lunar gravity mappers rocket to the moon atop a Delta II Heavy booster on Sept. 10 from Cape Canaveral, Florida. View to Space Launch Complex 17 gantry from Press Site 1
Credit: Ken Kremer (kenkremer.com)

Read Ken’s continuing features about GRAIL
NASA launches Twin Lunar Probes to Unravel Moons Core
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

NASA launches Twin Lunar Probes to Unravel Moons Core

Blastoff of Delta II Heavy rocket and twin GRAIL Lunar Mappers on Sept 10 blast off unveiled at night at Launch Pad 17B. GRAIL liftoff was postponed to Sept. 10 at 8:29 a.m EDT after high levels winds scrubbed the Sept 8 launch attempt. Credit: Ken Kremer

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NASA renewed its focus on ground breaking science today with the thunderous blastoff of a pair of lunar bound spacecraft that will map the moons interior with unparalled precision and which will fundamentally alter our understanding of how the moon and other rocky bodies in our solar system – including Earth – formed and evolved over 4.5 Billion years.

Today’s (Sept. 10) launch of the twin lunar Gravity Recovery and Interior Laboratory (GRAIL) spacecraft atop the mightiest Delta II rocket from Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT was a nail biter to the end, coming after a two day weather delay due to excessively high upper level winds that scrubbed the first launch attempt on Sept. 8, and nearly forced a repeat cancellation this morning.

Liftoff of the nearly identical GRAIL A and B lunar gravity mappers from Space Launch Complex 17B took place on the second of two possible launch attempts after the first attempt was again waived off because the winds again violated the launch constraints.

GRAIL A and B gravity mappers rocket to the moon atop a Delta II Heavy booster on Sept. 10 from Cape Canaveral, Florida. View to Space Launch Complex 17 gantry from Press Site 1.

Credit: Ken Kremer (kenkremer.com)


After the final “GO” was given, the Delta II Heavy booster suddenly roared to life and put on a spectacular show spewing smoke, flames and ash as it pushed off the pad and shot skywards atop a rapidly growing plume of exhaust and rumbling thunder into a nearly cloudless sky.

The solar powered dynamic duo were propelled to space by the last ever Delta II rocket slated to depart Earth from Cape Canaveral, Florida. After more than 50 years of highly reliable service starting in 1960, the venerable Delta II family will be retired after one final launch in October from Vandenberg Air Force Base in California.

GRAIL and Delta II rocket soar to space.
View to Space Launch Complex 17 Pad A & Pad B (right) from Press Site 1. Credit: Ken Kremer

On this special occasion the media were allowed to a witness the launch from Press Site 1 – a location just 1.5 miles away from the pad with a gorgeous and unobstructed view to the base of the pad which magnified the tremendous roar of the rocket engines.

“Since the earliest humans looked skyward, they have been fascinated by the moon,” said GRAIL principal investigator Maria Zuber from the Massachusetts Institute of Technology in Cambridge. “GRAIL will take lunar exploration to a new level, providing an unprecedented characterization of the moon’s interior that will advance understanding of how the moon formed and evolved.”

Delta II arcs over atop long exhaust plume casting shadow for long lunar journey. Credit: Ken Kremer

The spacecraft separation and deployment of the solar arrays worked exactly as planned, the mission team reported at a post launch briefing for reporters. Both probes are power positive and healthy.

GRAIL A and B are now speeding towards the moon on a low energy path that will take about 3.5 months compared to just three days for the Apollo astronauts. The slower and longer path covering more than 2.5 million miles (4 million kilometers) enables the spacecraft to use a smaller engine and carry less fuel for the braking maneuver required to place the probes into a polar elliptical orbit when they arrive at the moon about 25 hours apart on New Year’s Eve and New Year’s Day 2012.

“Our GRAIL twins have Earth in their rearview mirrors and the moon in their sights,” said David Lehman, GRAIL project manager at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “The mission team is ready to test, analyze and fine-tune our spacecraft over the next three-and-a-half months on our journey to lunar orbit.”

During the 82 day science phase, the primary objective of is to study the moons interior from crust to core and map its gravity field by 100 to 1000 times better than ever before. GRAIL A and GRAIL B will fly in tandem formation in near circular polar orbit at an altitude of some 50 km above the lunar surface as the moon rotates beneath three times.

GRAIL lunar twins depart Earth for the Moon
All 3 Air-lit solids have ignited after all 6 ground lit solids have been jettisoned.Credit: Ken Kremer

The mission will provide unprecedented insight into the structure and composition of moon from crust to core, unlock the mysteries of the lunar interior and advance our understanding of the thermal evolution of the moon that can be applied to the other terrestrial planets in our solar system, including Mercury, Venus, Earth and Mars.

Read Ken’s continuing features about GRAIL
GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

GRAIL Unveiled for Lunar Science Trek — Launch Reset to Sept. 10

Delta II Heavy rocket and GRAIL Lunar mappers unveiled at night at Launch Pad 17B. GRAIL liftoff was postponed to Sept. 10 at 8:29 a.m EDT after high levels winds scrubbed the Sept 8 launch attempt. Credit: Ken Kremer

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NASA’s Gravity Recovery and Interior Laboratory (GRAIL) moon mapping twins and the mighty Delta II rocket that will blast the high tech physics experiment to space on a lunar science trek were magnificently unveiled in the overnight darkness in anticipation of a liftoff that had originally been planned for the morning of Sept. 8.

Excessively high upper level winds ultimately thwarted Thursday’s launch attempt.

NASA late today has just announced a further postponement by another day to Saturday Sept. 10 to allow engineers additional time to review propulsion system data from Thursday’s detanking operation after the launch attempt was scrubbed to Friday. Additional time is needed by the launch team to review the pertinent data to ensure a safe blastoff of the $496 Million GRAIL mission.

There are two instantaneous launch opportunities at 8:29:45 a.m. and 9:08:52 a.m. EDT at Cape Canaveral, eight minutes earlier than was planned on Sept. 8. The weather forecast for Sept. 10 still shows a 60 percent chance of favorable conditions for a launch attempt.

GRAIL A and B enclosed in nose cone atop Delta II rocket at Cape Canaveral, Florida. Umbilical’s connect from Delta 2 to Fixed Umbilical Tower (FUT).
Credit: Ken Kremer (kenkremer.com)

Despite a rather poor weather prognosis, the heavy space coast cloud cover had almost completely cleared out in the final hours before launch, the surface winds were quite calm and we all expected to witness a thunderous liftoff. But measurements from weather balloons sent aloft indicated that the upper level winds were “red” and violated the launch criteria.

Mobile Service Tower is retracted from around Delta II rocket at Pad 17B. Credit: Ken Kremer

As the launch gantry was quickly retracted at Launch Complex 17B on Sept. 7, the Delta was bathed in xenon spotlights that provided a breathtaking light show as the service structure moved a few hundred feet along rails.

The cocoon like Mobile Service Tower (MST) provides platforms to access the rocket at multiple levels to prepare the vehicle and spacecraft for flight. The MST also protects the rocket from weather and impacts from foreign debris.

The GRAIL A and B mirror image twins ride side by side to space atop the Delta rocket. The washing machine spacecraft weigh about 677 pounds (307 kg) each.

The Delta II rocket stands 128 feet tall and is 8 feet in diameter. The first stage liquid and solid rocket fueled engines will generate about 1.3 million pounds of thrust.

During the Terminal Countdown, the first stage is fueled with cryogenic liquid oxygen and highly refined kerosene (RP-1).

GRAIL is an extraordinary first ever journey to the center of the moon that will — with its instruments from orbit — peer into the moons interior from crust to core and map its gravity field by 100 to 1000 times better than ever before. The mission employs two satellites flying in tandem formation some 50 km in near circular polar orbit above the lunar surface.

GRAIL A and B will perform high precision range-rate measurements between them using a Ka-band instrument. The mission will provide unprecedented insight into the formation and thermal evolution of the moon that can be applied to the other rocky planets in our solar system: Mercury, Venus, Earth and Mars.

After a 3.5 month journey to the moon, the probes will arrive about a day apart on New Year’s Eve and New Year’s Day 2012 for an 82 day science mapping phase as the moon rotates three times beneath the GRAIL orbit.

Photojournalists watch as Mobile Service Tower is retracted from around Delta II rocket at Pad 17B.
Credit: Ken Kremer

Xenon spotlights bathe Delta II rocket as Mobile Service Tower is retracted at Pad 17 and photojournalists watch from nearby at Pad 17B. Credit: Ken Kremer

Read Ken’s continuing features about GRAIL
Last Delta II Rocket to Launch Extraordinary Journey to the Center of the Moon on Sept. 8
NASAs Lunar Mapping Duo Encapsulated and Ready for Sept. 8 Liftoff
GRAIL Lunar Twins Mated to Delta Rocket at Launch Pad
GRAIL Twins ready for NASA Science Expedition to the Moon: Photo Gallery

Winds Delay Launch For GRAIL

GRAIL and its Delta 2 rocket on the launchpad. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

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High upper level winds put a damper on hopes for launching the GRAIL mission on its first attempts on Thursday, September 8. While the weather looked perfect on the ground at Kennedy Space Center, weather balloons showed high winds in the region of the atmosphere where the Delta 2 launcher would normally experience the most turbulence.

NASA will try again on Friday, September 9 with two one-second launch windows available at 8:33 and 9:12 EDT (12:33 or 13:12 UT). There were two one-second launch windows for Thursday, and both were “red” because of the winds aloft.

The dynamic duo twin-spacecraft Gravity Recovery and Interior Laboratory (GRAIL) mission is designed to map the Moon’s gravity with extreme precision.

For more information on the mission, read our preview article by Ken Kremer.

GRAIL on the launchpad. Credit: Alan Walters (awaltersphoto.com) for Universe Today.