Thursday, August 9, 2012

Little known facts about Mars

The world's attention has been focused back on Mars with the recent Curiosity landing.   NASA's  new robotic rover is beaming back pictures from the planet now that it has landed at the base of Mount Sharp.   

During its two-year mission, the roaming laboratory will analyze rocks and soil in search of the chemical building blocks of life, and determine whether there were habitable conditions where microbes could thrive.  Mars has been a prime target for space exploration for decades, in part because its climate 3.5 billion years ago is believed to have been warm and wet, like early Earth. 

Here are five little known Mars facts:
— Why is Mars red? It is called the red planet because the landscape is stained rusty-red by the iron-rich dust.
—Quick weight loss: Its gravity is only 38% that of Earth. So if you weigh 200 pounds on Earth, you would weigh 76 pounds on Mars.
—Temperatures: Mars' temperatures can range from 80 degrees at its equator to -199 degrees at its poles.
—Atmosphere: Mars' atmosphere is mostly carbon dioxide with traces of nitrogen and argon. Earth's atmosphere is a mixture of nitrogen, oxygen and other gases.
— Day length:  A day on Mars lasts 40 minutes longer than a day on Earth.

Wednesday, May 16, 2012

The Battle of Campeche

The Battle of Campeche is a little known, yet quite important naval battle between Texas and Mexico that took place in May of 1843.  The Alamo and the Battle of San Jacinto had taken place in 1836 gaining Texas the independence that was sought, but Mexico still was not satisfied and failed to recognize Texas as an independent entitity.  Texas was heading towards statehood which would be gained in 1845.

Commodore Edwin Ward Moore had been waging a campaign against Mexican fishing vessels in the Gulf and disrupting commerce, because it was mistakenly thought in Texas that Mexico was planning some type of amphibious assault in order to retake the rebellious province.  He could not fully retrofit and rearm his ships when he put in at New Orleans. The government of Texas refused him any more funds and subsequently ordered him back to Texas so that the fleet could be scrapped or sold.

Moore was against this idea and allied himself with the Yucatan government, who at the time was in open rebellion against the tyrannical central Mexican government. The Yucatan government reportedly paid Moore $8,000 a month for his services. Moore, now fully funded, set sail to lift the Mexican naval blockcade of the port of Campeche.

The Mexican Navy was much better funded and prepared.  They had recently contracted with England for a pair of state of the art warships.  Montezuma, was a wooden-hulled ironclad. Guadalupe was twenty feet shorter at 183 feet, but she had a special distinction. She was the first iron-hulled steam warship in the world. That combined with her two explosive shell firing Paixhan guns made everything else afloat obsolete.

The Texan/Yucatan navy was massively outgunned.  Moore encountered the much stronger Mexican squadron on May 16, which included the Guadalupe and the Montezuma, commanded by British officers and manned by both British and Mexican seamen. After approaching the Mexican fleet with extreme caution and trepidation, Moore engaged the Mexicans and British and created mass chaos. After three hours of broadsides both sides withdrew after sustaining considerable damage and casualties. The Texans suffered the most physical damage to their ships, while the Mexicans and British suffered more casualties.

Moore sailed the sloop-of-war Austin between the Guadalupe and Montezuma, where they could not fire without endangering each other. The Austin got off 530 rounds before the Mexican ships could disengage.   Guadalupe suffered 47 killed and lost one of her paddles. Montezuma lost 40 men, including Captain Cleveland of the Royal Navy.

The Battle of Campeche marked the first time exploding shells had been used in a naval engagement. It is also the only time steamers where ever defeated by sailing ships.

It was an important battle that has been mostly lost to history.  The Mexican-American War of 1846-1848 overshadowed the Battle of Campeche.

Thursday, February 23, 2012

Mayan Civilization failed due to Mild Drought conditions

Scholars have long believed that a major drought caused severe dry conditions that killed off the Mayan civilization known for its mastery of language, math and astronomy. But researchers from the Yucatan Center for Scientific Research in Mexico and the University of Southampton in Britain said their analysis shows the drought only caused reductions of 25% to 40% less annual rain.

The smaller amounts of rain meant that open water sources in pools and lakes evaporated faster than could be replaced by more precipitation, said the study in the journal Science.

"The data suggest that the main cause was a decrease in summer storm activity," said co-author Eelco Rohling of the University of Southampton.

The study is the first of its kind to attempt to assess exactly how much rainfall decreased between 800 and 950 AD when Mayan civilization went into decline, and bases its modeling data on records of past rainfall changes from stalagmites and shallow lakes. The analysis showed that modest dry spells could have sparked major water shortages in an area with no rivers, and no source of water other than rain.

"Summer was the main season for cultivation and replenishment of Mayan freshwater storage systems and there are no rivers in the Yucatan lowlands," added Rohling. "Societal disruptions and abandonment of cities are likely consequences of critical water shortages, especially because there seems to have been a rapid repetition of multi-year droughts."

International experts have predicted that similar dry spells in the Yucatan region are on the way due to climate change. While modern societies are expected to be better equipped to handle drought, risks remain, said lead author Martin Medina-Elizalde of the Yucatan Center for Scientific Research in Mexico.

"Our results show rather modest rainfall reductions between times when the classic Maya civilization flourished and its collapse between AD 800-950. These reductions amount to only 25 to 40% in annual rainfall," he said. "What seems like a minor reduction in water availability may lead to important, long-lasting problems. This problem is not unique to the Yucatan Peninsula, but applies to all regions in similar settings where evaporation is high."