(Premium) Gist of Science Reporter Magazine: December 2013

Premium - Gist of Science Reporter: December 2013

OPPORTUNITY COMPLETES TEN YEARS ON MARS

When NASA’s Mars rover Opportunity blasted c from Cape Canaveral in 2003, many observers expected the rover to survive not more than a few months. It was designed only for a three-month mission on the hostile Martian surface. On 7 July 2013, Opportunity celebrated the tenth anniversary of its launch and had spent nine years roving the red sands of Mars - and still making discoveries!

According to a recent NASA report, after nineplus years of traveling, Opportunity recently set the US space program’s all-time record for mileage on another planet. The milestone occurred on 15 May 2013, when the rover drove 80 metres, bringing its total odometry 35.760 kilometres or 22.220 miles. The previous mark had been held by the Apollo 17 moon rover, which astronauts Gene Cernan and Harrison Schmitt drove for 35.74 km (22.21 miles) across the lunar surface in December 1972.

Over the years, Opportunity has been photographing and sampling the Martian landscape. The surface of Mars of today is bone dry and hostile to life as we know it. Opportunity’s mission is to hunt for places where it wasn’t always so, places where ancient water might have nourished life forms native to Mars. The rover has found abundant evidence that liquid water was once present. For the past 20 months, Opportunity has been “working” the rim of Endeavour Crater. There, Opportunity found deposits of gypsum probably formed from groundwater seeping up through cracks in Martian soil. It has also found signs of clay minerals in a rock
named “Esperance”.

The rover is currently en route to “Selander Point”, a place on the rim of Endurance Crater where a treasure-trove of geological layers is exposed for investigation.

A visit to Solander Point will be like reading a Martian history book. Besides, there are north-facing slopes at Solander Point where the rover can tilt its solar panels toward the sun and ride out the coming winter. The minimum-sunshine days of this sixth Martian winter for Opportunity will come in February 2014.

If Opportunity survives another year, the rover might yet break the all-time extraterrestrial driving record set by Lunokhod 2, a Soviet robotic vehicle that traveled an estimated 26 miles (42 km) across the Moon in 1973.

THYROID CANCER RISK FROM DENTAL XRAY DIAGNOSTICS

Concerns have recently been raised regarding triggering of thyroid cancer due to X-ray-based diagnostic procedures. It is being recommended that patients should insist on a leaded collar, also called a Thyroid Guard, wearing it over the thyroid to protect it from radiation.

Most people in the developing world, including India, may not even be aware that a thyroid guard exists. A Thyroid Guard is a collar that is placed around the neck, covering the thyroid gland, to assure maximum protection for the patient. It may be a separate unit or a little flap on the top of the Lead Apron that can be lifted up and wrapped around the neck. The American Dental Association recommends that a Thyroid Guard be placed for all dental X-rays to reduce exposure to radiation. These concerns do not appear to be entirely unfounded. X-ray based diagnostics might actually be causing greater damage, than hitherto considered, to the thyroid gland and other tissues in the vicinity, including parathyroid glands and brain. People do not bother to ask for the Thyroid Guard during Xrays, especially during dental X-rays. The Thyroid Guard should be used to protect the technologist as well as anyone that has to be in the room with the patient being X-rayed.

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