Saturday, February 11, 2012

MOON AND MARS CAME CLOSER ON 9-2-12



Late on the night of Feb. 9, 2012, skywatchers who cast a glance toward the waning gibbous moon in the eastern sky will also notice the presence of a very bright, yellow-orange "star" shining with a steady glow hovering a bit above and to the moon's right.
That's no star, though. It's the plan
et Mars.

The apparent distance between
the moon and Mars will be rather large, amounting to about 9 degrees. That's roughly equal to the width of your fist held at arm's length. The sky map of Mars and the moon for this story shows how they will appear Thursday night to skywatchers with clear skies.

But even though the gap is quite large, the brightness of Mars at this time makes it stand out despite the much greater brilliance of the nearby moon. On this night, Mars will be 69 million miles (111 million kilometers) from Earth.

Mars is unmistakable once it rises in the east around 7:45 p.m. Its fiery-colored luster shines nearly twice as bright as the lighter-hued Arcturus star far to its lower left (Arcturus rises in the east-northeast a couple of hours after Mars). Mars currently shines at magnitude -0.8; excluding the moon, it is outshone in our current evening sky by only
venus, Jupiter and Sirius.

Mars will reach aphelion — its farthest point from the sun — on Feb. 15, a distance of 1.666 astronomical units, which corresponds to a distance of 154.9 million miles (249.2 million km). That doesn't bode well for getting good views of Mars at its upcoming opposition on March 3. In fact, the red planet will appear little more than half as large as it did at its close approach to Earth in August 2003.

Telescopes
show Mars' disk growing by about 13 percent during this month, though it will still appear relatively small; when it comes to opposition in just over three weeks, observers will need an eyepiece magnifying 133-power to make it appear as large as the full moon does with the naked eye.

Nonetheless, skywatchers should take this opportunity for some serious observing because Mars' apparent size is going to begin to slowly diminish by mid-March.

It is currently late spring in
Mars' northern hemisphere, equivalent to early June here on earth. In good telescopes, you might get a view of the shrinking polar cap appearing as a bright spot on the planet's disk. Wait until Mars is high in the southeast around 10:30 p.m. and start scrutinizing this most famous planet. It will reach its highest point in the sky in the south as it crosses the meridian soon after 2 a.m. local time.

Late at night, as Mars rises high, note its exact position beneath the right-triangle pattern of stars that represents the lion’s hind quarters.

The planet cato a standstill again before reversing direction and heading back toward the
me to a standstill against the background stars on Jan. 23. Since that date, it has been in retrograde motion (moving westward) and is approaching the bright bluish star Regulus. Right now, the two are separated by 21 degrees, but they'll be less than 5 degrees apart on April 15, when Mars' retrograde motion comes to an end and it comes east.

Tuesday, February 7, 2012

OLDEST LIVING THING DISCOVERED ON EARTH


Scientists say a patch of ancient seagrass in the Mediterranean is up to 200,000 years and could be the oldest known living thing on Earth. Australian researchers, who genetically sampled the seagrass covering  40 sites from Spain to Cyprus, say it is one of the world's most resilient organisms - but it has now begun to decline due to global warming.Australian scientists sequenced the DNA of samples of the giant seagrass, Posidonia oceanic, from 40 underwater meadows in an area spanning more than 2,000 miles, from Spain to Cyprus.
The analysis, published in the journal PLos ONE, found the seagrass was between 12,000 and 200,000 years old and was most likely to be at least 100,000 years old. This is far older than the current known oldest species, a Tasmanian plant that is believed to be 43,000 years old.