Wednesday, 27 November 2013

Observing Ison at perihelion

So far Comet ISON has spent November sinking ever lower in the east before sunrise as it heads toward the Sun. Ironically, the comet should brighten greatly as it disappears into the Sun's glare.

But you might have a long shot at seeing the comet at its very brightest, as it pulls a hairpin turn around the Sun on Thanksgiving Day, November 28th. Comet ISON will be physically closest to the Sun that day around 19h Universal Time. It will appear within one Sun diameter of the Sun's edge from about 17hto 20h UT. 





Use the chart to 
determine where the comet is with respect to the Sun. The comet's position is indicated every 12 hours (in Universal Time; adjust to your time zone accordingly), and celestial north is up.

As the chart shows, during its perihelion the comet swings around the Sun in a counterclockwise direction. It's due south of the Sun at 17:30 UT, very close to its southeast at 18:30 UT, due east at 19:20 UT, and farther northeast for several hours thereafter.


From Comet ISON's point of view, the Sun will be
enormous during its closest approach, filling the comet's sky and broiling its surface to a temperature of about 2,700° C (4,900° F). That's almost hot enough to melt iron, not to mention ice! The comet should peak in brightness from around perihelion until perhaps a few hours after.

Will it be detectable then? If you block out the Sun's disk very cautiously and carefully with no momentary lapses — put the Sun behind a chimney or lamp post, not your wavering finger — you might possibly detect the comet's fuzzy pinpoint of a head with the unaided eye if the air is very clear. Do not attempt this with binoculars or a telescope!
 

Blocking the Sun
Block the Sun's disk very cautiously using a chimney or lamp post (pictured here) — not your wavering finger — on November 28th, and you just might glimpse the comet's fuzzy-pinpoint head with the unaided eye. Do not attempt this with binoculars or a telescope!
S&T: Alan MacRobert
 

 

Ison increasing in magnitude





Ison v NASA


Monday, 18 November 2013

Once in a lifetime galactic fireworks display due from Comet Ison

Comet Ison, first spotted a year ago, is now visible to the naked eye and will continue to brighten as it hurtles toward the Sun.


Friday, 15 November 2013

What Happened to Mars? A Planetary Mystery

NASA's MAVEN (Mars Atmosphere and Volatile EvolutioN) spacecraft, inside a payload fairing, is hoisted to the top of a United Launch Alliance Atlas V rocket at the Vertical Integration Facility at Cape Canaveral Air Force Station's Space Launch Complex 41.Billions of years ago when the planets of our solar system were still young, Mars was a very different world.  Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm. In this cozy environment, living microbes might have found a home, starting Mars down the path toward becoming a second life-filled planet next door to our own.

But that's not how things turned out.

Today, Mars is bitter cold and desiccated. The planet's thin, wispy atmosphere provides scant cover for a surface marked by dry riverbeds and empty lakes. If Martian microbes still exist, they're probably eking out a meager existence somewhere beneath the dusty Martian soil.
What happened? This haunting question has long puzzled scientists. To find the answer, NASA is sending a new orbiter to Mars called MAVEN (Mars Atmosphere and Volatile Evolution).

MAVEN will launch from Cape Canaveral, Florida, during a 20-day period that begins on November 18, 2013. The trip to Mars takes 10 months, and MAVEN will go into orbit around Mars in September 2014. It will take 5 weeks for the spacecraft to get into its final science-mapping orbit, test
the instruments, and test science mapping sequences. After this commissioning phase, MAVEN has a 1-Earth-year primary mission during which it will make its key measurements.

Check out the latest NASA ScienceCast... http://www.youtube.com/watch?v=etL2ZhqGNCs