Isostasy, gravity, and the Moon! Last week the GRAIL lunar gravity mission published their first scientific results, and what they have found will send many geophysicists back to the drawing board to explain how the Moon formed and why it looks the way it does now.
MIT’s research on an ancient lunar rock suggests that the moon once harbored a long-lived dynamo — a molten, convecting core of liquid metal that generated a strong magnetic field 3.7 billion years ago. The findings, published in Science, point to a dynamo that lasted much longer than scientists previously thought, and suggest that an alternative energy source may have powered the dynamo.
“The moon has this protracted history that’s surprising,” says co-author Benjamin Weiss, an associate professor of planetary science at MIT. “This provides evidence of a fundamentally new way of making a magnetic field in a planet a new power source.”
How did Earth get its own Moon? For decades, the most popular origin story has been the “Big Splat” theory, which says an object the size of Mars impacted the Earthmore than three billion years ago, flinging material into space which became the Moon.
But now there’s new evidence that the Big Splat theory may be incorrect — and the impact that created the Moon may have been more like a hit-and-run accident.
On July 20, 1969, the Apollo 11 crew opened the door of the lunar module and Neil Armstrong stepped out onto the lunar surface. Armstrong’s radio back to Earth that his was ‘one small step for man, one giant leap for mankind’ became instantly one of the most quoted and known phrases uttered in the name of science. The Apollo program was started less than a decade earlier with success following success. Named by then NASA Director Abe Silverstein (who later said it was like naming his baby) after the Ancient Greek god known for knowledge and who was represented as a flaming chariot shooting across the sky. Hats off today to Buzz Aldrin, Neil Armstrong and Michael Collins. All born in 1930 and still healthy and looking to the skies.
Thanks also to the flight crew:
Charlie Duke, Capsule Communicator (CAPCOM)
Ronald Evans (CAPCOM)
Owen K. Garriott (CAPCOM)
Don L. Lind (CAPCOM)
Ken Mattingly (CAPCOM)
Bruce McCandless II (CAPCOM)
Harrison Schmitt (CAPCOM)
Cliff Charlesworth (Green Team), launch andEVA
Gene Kranz(White Team), lunar landing
Glynn Lunney(Black Team), lunar ascent
All images courtesy NASA, used with permission and in the public domain. Please copy and share!
I got a text from my dad this morning, saying “Tranquility Base here, the Eagle has landed.” That’s his way of reminding me that today is the anniversary of the Moon landing.
Titanium signature poses puzzle for popular theory of Moon’s origin.
A chemical analysis of lunar rocks may force scientists to revise the leading theory for the Moon’s formation: that the satellite was born when a Mars-sized body smacked into the infant Earth some 4.5 billion years ago.
If that were the case, the Moon ought to bear the chemical signature of both Earth and its proposed ‘second’ parent. But a study published today in Nature Geoscience1 suggests that the Moon’s isotopic composition reflects only Earth’s contribution.
NASA GRAIL returns first student-selected Moon images
This image of the far side of the lunar surface, with Earth in the background, was taken by the MoonKAM system board the Ebb spacecraft. Fourth grade students from the Emily Dickinson Elementary School in Bozeman, Mont., received the honor of making the first image selections by winning a nationwide competition to rename the two spacecraft.
Previously named Gravity Recovery And Interior Laboratory (GRAIL) A and B, the twin spacecraft are now called Ebb and Flow. Both washing-machine-sized orbiters carry a small MoonKAM camera. Over 60 student-requested images were taken by the Ebb spacecraft from March 15-17 and downlinked to Earth March 20.
MoonKAM is based on the premise that if your average picture is worth a thousand words, then a picture from lunar orbit may be worth a classroom full of engineering and science degrees. Through MoonKAM, students have an opportunity to reach out to the next generation of scientists and engineers.
GRAIL is NASA’s first planetary mission to carry instruments fully dedicated to education and public outreach. Students will select target areas on the lunar surface and request images to study from the GRAIL MoonKAM Mission Operations Center in San Diego.
Aristarchus Plateau is anchored in the vast lava flows of the Moon’s Oceanus Procellarum. At the plateau’s southeastern edge lies the spectacular Aristarchus Crater, an impact crater 40 kilometers wide and 3 kilometers deep. Scan along this remarkable panorama and you will find yourself gazing directly at the crater’s west wall for some 25 kilometers. Features along the terraced wall include dark impact melt and debris deposits, bright excavated material, and boulders over 100 meters wide. At a full resolution of 1.6 meters per pixel, the sharp mosaic was created from images recorded by the Lunar Reconnaissance Orbiter’s narrow angle camera in November of 2011. The orbiter’s vantage point was 70 kilometers east of the crater’s center and only 26 kilometers above the lunar surface.