Thursday, December 31, 2009

Christmas in Space

Welcome back and Happy Holidays! This is the office door at Johnson Space Center, Honourable mention in the Christmas decorating contest!

In December 1968 the crew of Apollo 8 celebrated Christmas Eve while orbiting the Moon. On December 20, 2009 the 3-member (American, Russian and Japanese) crew of Expedition 22 lifted off for ISS. Continued occupation means that every year someone will celebrate Christmas in Space.


Friday, December 18, 2009

Water, Water Everywhere

From the American Geophysical Union meeting in San Francisco: Wednesday the talk was about water on the Moon. In 1999, as the Cassini spacecraft passed the Moon on the way to Saturn, the Visual Infared Mapping Spectrometer (VIMS) found the 3-micron signature of water molecules and hydroxyl. Though found 10 years ago, this discovery was not published until this September.

This year the finding was confirmed by the Moon Mineralogy Mapper (M3) aboard India's Chandrayaan orbiter. Further confirmation was found from the Epoxi spacecraft which passed the Moon in June 2009 on its way to encounter a comet. Corroborating evidence from 3 missions show water and/or hydroxyl on the Moon. Today the Moon, once thought drier than a bone, is known to contain water.

As seen in this slide from yesterday afternoon, the two major 'water relations' on the Moon are temperature and composition. Cold terrain, such as near the poles contains more water. Mare contain less water than the lunar highlands. For these reasons, polar highlands are considered to be likely locations for settlement.

In response to this writer's question, another speaker noted that 10^21 kg asteroid Ceres could be composed of nearly 30% fresh water. While Earth contains about 10^21 kg water, not all of it is fresh. Ceres could potentially contain more fresh water than Earth! The asteroids are also potential sites for human mining. With possible changes in NASA's visions for the Moon and beyond, humans could venture to an asteroid in the near future.

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Thursday, December 17, 2009

Asteroid Lecture Tonight

In case you are also here in San Francisco during the AGU meeting: tonight is a free public lecture, "Near Earth Comets and Asteroids: Finding Them Before They Find Us" 7:00 PM at the Exploratorium. The museum at 3601 Lyon Street (around the corner from Palace of Fine Arts) is a fun place to visit. The city is decked out in holiday lights--so much for "dark energy!"


Monday, December 14, 2009

Age of the Solar System

This morning we are at the huge American Geophysical Union meeting in San Francisco with over 15,000 scientists! This morning Dr. M. Wadhwa gave a new estimate of the Solar System's age, 4568.7 (+0.2/-0.4) million years! We also heard from B.E. Schmidt that asteroid Ceres could contain 30% water. Potentially Ceres could have more fresh water than Earth! More coming soon!

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Friday, December 11, 2009

Life From Mars

Humans have long asked about life on Mars. In 1976 the Viking Lander brought experiments designed to find chemical reactions indicative of life. To scientists' surprise, those reactions were found in abundance. Researchers explained the positive results as chemical reactions, even inventing reactions that had never been observed on Earth. After Viking, Mars was officially called lifeless.

25 years ago this month geologist Robbie Score spent her Christmas holiday Wintering in Antarctica. On December 27, 1984 she was hunting for rocks on the Far Western Icefield near the Allan Hills. She spotted an odd grapefruit-sized rock on the ice. Score immediately identified it as a meteorite, and its greenish colour made it distinct from other meteorites found nearby. Bobbie Score named the rock ALH84001, an Allan Hills meteorite found in 1984. For nine years the odd green rock sat on a shelf unnoticed, but Robbie Score may have stumbled upon one of history's great finds.

An early classification identified ALH84001 as coming from an asteroid. In 1993 geologist Duck Mittlefehldt, a friend of Robbie Score, reexamined the little meteorite and concluded that it had arrived from Mars. Later analysis showed that the rock had first crystallized 4.5 billion years ago, near the dawn of our solar system. 16 million years ago it was launched from Mars by a meteorite impact. After wandering the solar system for millions of years, the green rock landed in Antarctica 13,000 years ago.

The biggest surprise was yet to come. In 1996 colleagues David McKay, Everett Gibson and Kathie Thomas-Keprta discovered signs of bacterial life on ALH84001. They foundd several major bits of evidence, including magnetites and fossil-like forms. Magnetites are used by living organisms to sense direction. After an initial blast of publicity, other researchers found alternate explanations. The debate over life on Mars raged on.

The team's latest paper, Origins of magnetite nanocrystals in Martian meteorite ALH84001, does a good job of demolishing competing theories. Afer painstaking work, the team shows that alternate explanations of the magnetites are contradictory. This paper will convince many on the fence that life has been discovered from Mars. NASA press release.

The Martian bacteria were thriving at a time when astrophysics says that the Sun was only 75% as bright, and both Earth and Mars were frozen solid. Reality has not cooperated with theory, for evidence says that both planets had temperatures suitable for life. This is the "Faint Young Sun Paradox." Fortunately the Sun turns fuel to energy according to E=mc^2. If the speed of light were changing according to GM=tc^3, solar luminosity would be changed exactly enough to make temperatures comfortable for life.

When evidence is found that c is changing, others are quick to come up with alternate explanations. This is how "dark energy" got started. As with life on Mars, an abundance of evidence will show a changing speed of light.

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Monday, December 07, 2009

Student Day

For this blog's followers in Persia (Iran): Today is not just Pearl Harbour Day, it is National Student Day. This is a day to protest the unspeakable regime in Tehran. The Basij and RG will start detaining people whether guilty or not, so the people must rise up. People Power is the only hope to prevent this nuclear-mad regime from succeeding.


Friday, December 04, 2009

Snow Day

December 4, 2009

This morning at Johnson Space Center the snow started falling. Many JSC employees (not this one) were sent home early. This is the earliest Snow Day in Houston on record. Snow Day comes in the midst of controversy about Earth's climate. This issue involves climate data from NASA's Goddard Institute of Space Studies. The climate is a complex issue, involving everything from human activity to solar luminosity and the speed of light. As readers have seen before, "c change" us coming in science.


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