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Sunday, January 1, 2012

GRAIL-B in Lunar Orbit: Let the Mapping Begin




The GRAIL-B gravity mapping spacecraft has shutdown its engine to enter orbit around the moon. Deep space antennas are tracking the probe's progress. The GRAIL-A spacecraft went into orbit around the Moon successfully yesterday, [Mission Updates].

Over the next couple of months, a series of shorter engine firings will nudge the spacecraft into circular orbits passing over the Moons poles, 34 miles above its surface to commence the collection of gravitational data with precision factor of 1000 times better of the lunar far side than any of the previous 100 lunar missions since 1959.

In March, the spacecraft will begin collecting the gravity data. Variations in density for example, a mountain range or a clump of heavier metals below the surface change the Moon's gravitational pull and create wobbles in its orbits, and the gravity map will be calculated from the changes in distance and speed between the two spacecraft. The spacecraft will also activate MoonKam.

More from the BBC, The Washington PostAP and BBC4 audio.


Detecting ExoPlanets via Transit of Stars


In this one-hour October 2011 STEI lecture, Dr. Laraunce Doyle talks about how he led the Kepler team that discovered the Kepler-16b circumbinary planet.

Doyle also discusses several techniques for the detection of circumbinary planets (CBP, planets that circle two stars at once). This involves detection by transits (which in the case of CBP produce a quasi-periodic signal), eclipsing binary (EB) timing, dynamical timing of EBs, and a new detection technique called the "eclipse echo" EE method.



Annual Eclipse May 20, 2012, in Wild West


On Sunday, May 20, 2012, an annular solar eclipse sweeps across east Asia, over the northern Pacific Ocean, and then into the southwestern United States. This is eclipse is the first of three remarkable astronomical events of 2012, followed by the transit of Venus on June 5-6, 2012, and a total solar eclipse (TSE) on November 13, 2012. The Annular Eclipse is commonly known as the Ring of Fire.

An annular eclipse occurs when the moon passes directly in front of the sun, but does not completely obscure it, leaving a ring or "annulus" of sunlight flaring around the lunar disk. It is the first annular eclipse to be seen from the United States in 18 years.

The moon can be seen directly in front of the sun first from the southeast edge of China, then Japan, at its greatest at the International Date Line in the Pacific Ocean just south of the island chain stretching from Alaska, across the southwest corner of Oregon, northern California, the middle half of Nevada, southwest Utah, northern Arizona, northwest to southeast New Mexico, and right at sunset, the southern part of the Texas panhandle.

For example, from Austin, Texas, you can observe the partial eclipse from 7:34 pm until sunset at 8:21 pm. The point of greatest eclipse occurs south of Kiska and Buldir in Alaska at 23:52:46 UT. It is visible for 5 minutes and 46 seconds in this area. Be sure to not look directly into the sun without proper protective glasses or sun filter.


Rare Venus Transit set for 5-6 June 2012

One of the more remarkable cosmic events the the year 2012 will be the second Venus solar transit in the current cycle. Mark your new 2012 calendar for June 5-6, 2012. This is the second transit of the cycle pair with the last in June 2004. The June 2012 Venus Transit will be the last chance in the 21st century for a human to see it.

The transit of Venus is a rare, twice in a lifetime occurrence. Twice because it always happens in pairs, 8 years apart, but those pairs can be as much as 105.5 to 121.5 years apart. The last time this occurred before this pair began was December 6, 1882, the next such alignment occurs in December 2117 and again in 2125.

The best place to see the 2012 transit is in the Pacific Ocean - including Hawaii, Alaska, and central Pacific islands. Some organizations have begun to prepare for the 2012 transit well in advance, including a group organizing festivities and observation in Tahiti, with the beginning of the transit visible from North America.



TSE Set for Australia - November 14, 2012

The year 2012 also bring another Total Solar Eclipse (TSE, in the jargon) to be seen in "The Land Down Under" along the Great Barrier Reef.

The most populous city to experience totality will be Cairns, Australia which will experience 2 minutes of totality just an hour after daybreak (6:38 am AEST) with the sun at an altitude of just 14 on Wednesday, November 14, 2012.

The center line of the TSE will also be at Oak Beach, Australia and at sea. Although the total eclipse will last just over 4 minutes at maximum, only the beginning of the eclipse occurs over land, so at sea may be the better option for the eclipse chasers. For TSE travel information, check Eclipse2012.org.au



The Star Betelgeuse to make history in 2012?

"You might have seen the recent articles about Earth possibly having had two moons, but have you also read that Earth might soon have two suns? Well, at least temporarily," notes the first female commercial astronaut, Anousheh Ansari.

"Betelgeuse which is one of the brightest stars in our night sky, is the reason for this change. Evidence is pointing at Betelgeuse's imminent demise and as we know when a star collapses, it could go super-nova at any time. When this happens for a brief period of time, maybe a few weeks, we would have two suns in the sky. Furthermore, for the duration, we may not have any "nights" at all. According to Dr. Brad Carter of University of Southern Queensland, this could happen as soon in 2012, or maybe later, Ansari writes in her most recent newsletter.

Some have debunked the exploding star debate. Some suggest an object as bright as the moon, perhaps a million years from 2012, if Betelgeuse were to go supernova.

"There are speculations around this event, some of which of course include doomsday theories. However according to Dr. Carter, the event is harmless to Earth and the resulted neutrino shower could even be beneficial to Earth," astronomer Ansari writes.

So will the Betelgeuse star make significant Earth history in 2012? Maybe so, probably not.