Cumberland-Times Sky Columns
September 2005

September 4- Tenth Planet and Asteroid Interception
September 11 - Earth in Trouble
September 18 - Our Space Future
September 25 - Star Group Guides

September 4th - Tenth Planet and Asteroid Interception

In the years following Pluto's discovery in 1930, there was a feeling that Pluto might be a moon of a yet larger planet. The search for X continued decade after decade. In the 1970's Charles Kowal at Mt. Palomar Observatory discovered Chiron, an asteroid whose orbit was in the vicinity of Saturn and Uranus, far from the other known asteroids. In the 1990's, robotic telescopes began to comb the Kuiper belt, the region of the solar system beyond the orbit of Neptune. Over 400 objects were discovered there with the biggest object about half the size of Pluto. Last year, the farthest asteroid was found; this is Sedna, named after an Inuit goddess who dwelt in a cave at the bottom of the Arctic Ocean. Sedna has a very eccentric orbit that takes it nearly 1000 times farther from the sun than Pluto and outside the Kuiper Belt.

In early January 2005, the same team that discovered Sedna found a larger body. From its light and absence of infrared radiation, the team of Brown, Trujillo and Rabinovitz are certain that the object's size is in between Pluto (1485 miles) and our moon's size (2160 miles). It's temporary name is 2003 UB313. Presently the object is 9 billion miles from the sun, about 3 times as far away as Pluto. At this distance from the sun, 2003 UB313 has a surface temperature of -415 F degrees below zero. This Kuiper belt object takes 560 Earth years to orbit the sun. 2003 UB313's orbit has a tilt of 44 degrees to the plane of the solar system, more than twice the tilt of Pluto (the previous planet record holder). It's minimum solar distance is 3.3 billion years, close to the edge of Neptune's orbit. Once permission is granted by the International Astronomical Union (IAU), the search team hopes to name the body Xena, after the Grecian warrior princess (who had her own TV series a few years ago). 2003 UB313's orbit is well known due to it's being captured on wide angle photographs taken in 2003 by the 4 foot wide Schmidt telescope on Mount Palomar.

Will 2003 UB 313 be called the tenth planet? The decision is up to the IAU.

INTERCEPTING AN ASTEROID
Asteroids are mini-planets, of which the great majority dwell in the asterioid belt, between the orbits of Mars and Jupiter. The largest of the belt asteriods is Ceres, about 1000 km across (the size of Texas). Most asteriods are much smaller, typically a kilometer across (the size of our FSU campus). While most asteroids keep their distance from Earth, there are probably about 1,000 asteroids that dwell in the inner solar system and may cross the Earth's orbit.
Last summer, a robotic telescope discovered a 1,000 foot wide asteriod that crosses the Earth's orbit. The object is 99942 Apophis. Once Apophis' orbit was determined, it's future positions decades ahead were generated by computer. There was shock when an early study showed Apophis to be on a collision course with the Earth in 2029! More early observations were utilized to refine Apophis' orbit; new calculations showed that Apophis would instead pass 22,600 miles from the Earth on April 13, 2029, a little less than three Earth diameters! From Europe and western Africa, Apophis would then be visible to the eye.
The most recent calculations show that there is a chance that Apophis may in it's 2029 approach pass through a gravitational "keyhole" about 1/2 mile across. This passage would put Apophis on a course that would result in its colliding with the Earth in 2036! Such a collision might cause devastation over a large area, killing millions, with damages into the hundreds of billions of dollars! This impact would be far worse than the Siberia impact in 1908 but not on the same scale as the 65 million BC impact that killed off the dinosaurs.

It has been suggested that NASA send a radio beacon to this asteroid in the next 6-8 years so it can be tracked more easily. Then sometime early in the 2020's an interception probe would be lauched to deflect the asteriod from its course. It would be foolish to 'nuke' the asteroid. NASA could shroud some of the asteriod in foil to cause the force of sunlight to alter Apophis' orbit. Another possibility is to land a small ion engine on Apophis that could be fired over many months to slowly change Apophis' orbit.

September 11th - Earth in Trouble

Our September planetarium program, "Earth - Now and Future" deals with Earth problems that will affect all our lives in the next few decades. Our program begins with a quick review of sky basics that you need to understand what's in the sky and how the sky changes. We then cover the big sky events in September and October 2005, which include the drawing apart of brilliant Venus from Jupiter low in the western dusk, our two famed full moons (Harvest Moon in mid September and Hunters Moon in mid October)and Mars' close approach to Earth in late October.

The Earth portion of the program starts with the three key quantities that make the Earth the only planet with a great abundance of surface life forms. Our human population is growing by 10% every 6 years. Presently, our species is using 50% of the available water, using 40% (either directly or indirectly) of the annual global plant growth and 35% of the annual harvest of fish. We are consuming oil and natural gas so quickly that in about a decade, half of both of these quantities will be gone. In the past, whenever the half way point is reached, the production of these resources will drop and the prices rise, resulting in severe shortages.

If we focus on our country, there are some troubling trends. The United States with less than 5 % of the world's population consumes 25 % of the world's annual production of oil. The U.S. production of oil peaked 33 years ago (1972) and has been in decline ever since. Presently 57% of the gasoline we pump comes from foreign oil. Two thirds of known reserves lay in the Middle East, where the inhabitants have disdain for the U.S. The U.S. legal system makes it easy for small groups to thwart any new energy initiatives in Wind Power and Nuclear Energy by preying on peoples' fear. At the same time, the U.S. has become the World's greatest debtor nation. Our trade inbalance and national debt cause a great outflow of dollars; presently these dollars flow back into the U.S. to be invested in Treasury Bonds and U.S. companies. So we are relying on foreign investors to keep our economy afloat.

What steps are needed to be taken to ensure our country's future? We need leaders who will work tirelessly on these grave national problems rather than their quest for reelection and building up their party's power base. We need to repudiate through public demonstrations those selfish groups that would stop any new energy initiatives. Two great national goals must be: securing our borders, and ports and rebuilding our nation's manufacturing base with new products and new technology. We need to begin a long conversion from hydrocarbon fuels to Hydrogen, the most abundant element in nature. (Hydrogen generation could be done by wind turbines.) When hydrogen burns, it creates only water vapor.

September 18th - Our Space Future

Many Baby Boomers were raised at a time when human space exploration was glorified. But it has been nearly 33 years since our astronauts walked on the moon. Even after the last three Apollo missions were cancelled, most people were looking forward to space stations that would allow many more people to experience outer space than the moon flights, which took humans nearly 1/4 million miles from the Earth. The first space station was the SkyLab, launched into orbit in May 1973 by a Saturn rocket left over from the Apollo project. SkyLab slowly spiralled towards the Earth and was incinerated over the Pacific in July 1979. (There was hope that the Shuttle would be operational by then so as to raise SkyLab into a higher orbit and keep it aloft. The Shuttle's first flight was in April 1981.)

After several small Soviet space stations, the U.S.S.R. put into orbit the Mir Space Station in February 1986, a space platform designed for five years that lasted till 2001(when it was deorbited by rocket). Our current Space Station, the International Space Station (ISS) began with the orbiting of the Russian Zarya module in 1998. Since then most of the Space Shuttle missions have been to the ISS, adding more and more components. After the Shuttle Columbia disintegrated upon reentry in January 2003, the ISS has slowly spiralled closer to the Earth. Its average altitude is now about 218 miles, compared to its intended altitude of 250 miles. As the ISS has no rockets on board, its prime way to keep its orbit from decaying is a boost into a higher orbit by the Space Shuttle. (The Russian supply ships and Soyuz capsules can only raise the ISS only a mile or two higher.) So the further cancellation of Shuttle flights till next year is not a good omen for the ISS.

My hope is that the Shuttle will fly a few times a year till the end of the decade, allowing needed boosts to keep the ISS from a fiery death in the atmosphere. It's likely in the next decade that manned private enterprise flights will surpass NASA's orbital flights. Perhaps the ISS could offer itself as an orbital motel for the super rich. Unfortunately $10 million a night per couple will exceed most peoples' credit card limit!

It is increasingly clear that the best way to explore space is not by fragile humans but by robots, who can easily tolerate extended space missions. The human body is not built to handle long term weightlessness. We need gravity to maintain our bone density and keep our heart muscles strong. Let more advanced robots roll across the surface of Mars, collecting rocks and soil that could be returned to Earth laboratories. Then we could answer the question, "Did life ever exist on Mars?" We could send farmer robots to Mars to seed its polar caps' ice with hardly organisms. This could start a slow transformation of Mars into a life bearing world.

September 25th - Star Group Guides

It's fun to be able to recognize the main star groups such as the Big Dipper and the Hunter. Most evening bright groups can be seen a number of times for two seasons before they drop out of view behind the trees or in back of the hills. (The motion of the Earth about the sun causes a gradual drift of the evening stars towards the west that sweeps several prominent groups out of view each season. But at the same time, new groups swing into view in the eastern evening sky.)

Most books use the term 'constellation' but this word refers to a specific area of the sky that includes much more than the star figures. I prefer to use the term 'star group', referring to the patterns or star pictures that most people want to see.

In addition to a good sky book, you need a dim flashlight to view your sky charts without losing your 'night vision'. A good sense of the cardinal directions (north, east, south, west) can make the difference between success and giving up. (The easiest way to find North is to look at your shadow in mid day, when the sun shines in the South.)
The most prolific author for children's science books is Janice VanCleave. The Allegany County Libraries have her book, "Constellations For Every Kid" in the shelves. VanCleave's book is for latitude 40 degrees North, very close to Cumberland's latitude.

"Constellations" features easy to do home exercises to help beginners understand key concepts such as celestial coordinates, the wobbling of the Earth's axis and how a star's brightness changes with distance. I applaud VanCleave's choice of a few key star groups for each season's evening sky. "Constellations" ISBN is 0-471-15979-4 for paperback. It's Dewey Decimal number is 523.8 (where this book and similar books are found in our local libraries).
A different kind of sky guide is a Star Atlas. A modestly priced atlas that may be found in the reference areas of libraries is the "The Cambridge Star Atlas" by Wil Tirion. Just as for VanCleave is the leading author of children's science books, Tirion is the most popular sky mapmaker, collobarating with a number of authors on sky guides. This star atlas opens with a very nice inverted moon map so as to match the view through an astronomical telescope. (With the exception of binoculars and spotting scopes, most telescopes used in astronomy invert (flip the image upside down).) After the moon maps, there are 12 monthly sky maps, for both northern and southern latitudes. Tirion uses star figures that are similar to H.A. Rey's cartoons. His monthly maps show all the stars you would see on a moderately dark night. The main part of this Atlas are 20 sky charts, showing all stars visible the unaided eye and the positions of star clusters, gas clouds (nebulae), galaxies and the outline of the Milky Way. If you own your Atlas, you can trace lightly with a pencil the star patterns such as Leo, Perseus on these charts to make them easier to use. The all sky maps at the end of the Atlas, show in separate charts: the star figures, the star clusters, the globular star clusters, the ghost like shells of gas around dying stars (planetary nebulae), the gas clouds and the galaxies beyond our Milky Way. The second edition of "Cambridge Star Altas" has ISBN 0 521 56098 5 and a Dewey Decimal number of 523.8 .