Out of This World

The scientific theory I like best is that the rings of Saturn are composed entirely of lost airline luggage.
-Mark Russell

I'd like to end this year with an amazing image from the Cassini spacecraft orbiting Saturn. The large moon in front is called Dione. In the background you can see Saturn’s rings on the left, nearly edge-on, and two more moons as well: Epimetheus, only 130 km (70 miles) across, and Pandora, slightly smaller at 104 km across.

Pandora was discovered in 1980 by the Voyager 1 probe, Epimetheus was discovered by astronomers in 1966. Dione was discovered long ago in 1684 by the astronomer Cassini (for whom the space probe is named). At 1122 km in diameter, Dione is the 15th largest moon in the Solar System and is more massive than all known moons smaller than itself combined.

Bottom Line

This so reminds me of covers of Sci-Fi magazines of the 1950's with an imaginary sky of a planet far away but this is real and Cassini is there; seven years imaging Saturn and its moons.

May 2012 bring amazement and wonders and joy to one and all.

Bonus Image

Another excellent photo from Astronomy Picture of the Day. You may recall that a lunar eclipse is caused by the moon passing through the Earth's shadow but this multiple-exposure really makes that shadow visible. (And gives one a feeling for the size of the moon compared to Earth)

Odd Items in Space

For here am I floating round my tin can
Far above the world Planet Earth is blue
- lryics from David Bowie’s Ground Control to “Major Tom”

New Scientist reports that the next Space Shuttle mission will carry a piece of the apple tree that Newton sat under when an apple on the head led to a theory of gravity. The wood chip is on loan from the Royal Society of London which is celebrating its 350th anniversary of dedication to science.

Other unusual objects that have flown into space include:

1. Metal shielding on the Mars rovers made from World Trade Center scrap after 9/11

2. A 400 year-old lead tag bearing “Yames Towne” to honor the founding of the Jamestown colony in the US. The space shuttle Atlantis flew the tag across the Atlantic in a matter of minutes in low-earth orbit; compared to the many months the original voyage took.

3. When Apollo 11’s Eagle landed on the moon, it carried a piece of wood and cloth from the original Wright brother’s plane.

4. The ashes of the man who discovered Pluto, Clyde Tombaugh, are now flying to Pluto aboard NASA's New Horizons probe and should arrive in 2015.

5. Voyager 1 and 2 have both flown past the planets and out of the solar system. Each carries a record of voices from around the world (and instructions to aliens on how to play the record).

6. Movie items in space include Buzz Lightyear on the space station and Luke Skywalker's lightsaber for the 30th anniversary of Star Wars.

7. Apollo 15 took several hundred collector stamps and stamped them “cancelled” on the moon. This caused a furor over who would profit from selling them and NASA had to change the rules on what was allowed in space.

Pluto discover, Clyde Tombaugh, is not the only person with his ashes in space.
Others include:

Timothy Leary, “Tune in, Turn on, Drop Out” proponent of LSD (1997 orbit)

Gene Roddenberry, creator of Star Trek (1997 orbit)
(the ashes of his wife, Majel Barrett, who played “Nurse Chapel “ and the voice of all Star Trek computers, will fly into deep space in 2012 alongside additional ashes from Gene.)

Dr. Eugene Shoemaker, co-discover of the Shoemaker comet that crashed in Jupiter (1999 moon probe)

James Doohan, “Scotty” of Star Trek (2007 suborbital). Doohan will also accompany the Roddenberry’s on the 2012 deep space probe.

Each year a company called Space Services (formerly Celestis) launches a “symbolic portion” of ashes of anyone for a fee.
$ 700 for a rocket that returns to Earth
$2,500 for orbit
$10,000 for the moon starting in 2011
$12,500 aboard a deep space probe

Bottom Line

The New Scientist space item gallery includes this interesting tidbit:

Madalyn Murray O'Hair, founder of American Atheists, once “the most hated women in America” for her successful lawsuit to stop school prayer, also sued NASA in 1970 after the Apollo 8 crew read verses from the Book of Genesis while in space. She argued that government employees should not promote religious ideas. The Supreme Court threw the case out on the grounds that it had no jurisdiction in outer space.

A Sunday Extra. The first picture of Earth taken from another planet,
i.e. from the Mars Exploration Rover Spirit in 2004.

When Asteroids Attack

“Noise proves nothing. Often a hen who has merely laid an egg cackles as if she laid an asteroid.” - Mark Twain

An article at NewScientist.com, Asteroid attack: Putting Earth's defences to the test, describes a day-long test by the US Air Force in December of last year to test its readiness in the case of an asteroid impact. The US Air Force brought together scientists, military officers and emergency-response officials for the first time to assess the nation's ability to cope with an asteroid striking the Earth in just three days. The exercise was a wake-up call for the Air Force: there is no plan for what to do, the early-warning systems are woefully inadequate, and was no formal coordination between major parties like the Air Force, Homeland Security and NASA.

So it is not unreasonable to ask, should we panic? The answer is no. The best known impact in modern times was a comet 30 to 50 meters across that exploded over Tunguska, Siberia, in 1908, flattening trees for dozens of kilometres all around. The chance of a similar impact is about 1 in 500 each year, or a 10% chance of an impact in the next 50 years. The odds of a dinosaur killing, giant asteroid are much, much lower. But let’s assume you beat the odds and the next small comet or asteroid hits in your lifetime. Well the earth is a very big place with 70% of it covered in water. NASA used to fear that an ocean impact would create giant city-swamping tidal waves but recent research shows that the waves will lose energy before hitting land. (Unless the comet hits close to shore.)

What would an asteroid impact look like? A lot like an atom bomb. The heat of entry will cause the rock or comet to explode in a bright flash of light with a huge pressure and heat wave 30 seconds after. The only difference will be a lack of radiation. Since an asteroid and nuclear bomb are so similar, NASA warned the world when it calculated that a car sized asteroid would hit somewhere in the Middle East last year. They did not want a World War started because an Arab nation thought it had been nuked. Fortunately 2008 TC3 exploded over an unpopulated desert area of northern Sudan and never reached the ground.

Bottom Line

To its credit NASA was able to predict where and to the minute when the 2008 TC3 asteroid hit. To our shame, we had just 20 hours warning of this particular asteroid. And we were lucky to have spotted it at all. Our telescopes are blind to objects moving at us from the direction of the sun or even the moon. Two of the world's three leading asteroid detecting telescopes are based in Arizona, a region that clouds over between July and September.