November Viewing

Comet ISON will continue to get brighter throughout November as it reaches its perihelion (closest distance tot he Sun) on November 28th (Thanksgiving Day in the USA). By mid-month, ISON should reach visibility to the naked eye pre-dawn.

CLICK here for complete ISON Timeline

ISON will be approximately 800,000 from the Sun’s surface (That’s close!!!), and it’s possible that the Sun could break apart ISON. Alternatively (and most likely) ISON will whip around the Sun and emerge brighter to the naked eye here on Earth with an elongated typical comet tail.

In November, ISON will pass very close to the bright star Spica and the planet Saturn, both in the constellation Virgo, which will help you locate the Comet. NO — it’s not near Saturn of course but near it in Earth’s sky.

Though ISON will be bright as it nears the Sun, the problem is that it may be obscured by the Sun’s brightness. It should be about 4.4 degrees from the Sun at Perihelion (about 9 widths of the Sun) .

November 2013 ISON Comet Viewing

Comet ISON will continue to get brighter throughout November as it reaches its perihelion (closest distance tot he Sun) on November 28th (Thanksgiving Day in the USA). By mid-month, ISON should reach visibility to the naked eye pre-dawn.

CLICK here for complete ISON Timeline

ISON will be approximately 800,000 from the Sun’s surface (That’s close!!!), and it’s possible that the Sun could break apart ISON. Alternatively (and most likely) ISON will whip around the Sun and emerge brighter to the naked eye here on Earth with an elongated typical comet tail.

In November, ISON will pass very close to the bright star Spica and the planet Saturn, both in the constellation Virgo, which will help you locate the Comet. NO — it’s not near Saturn of course but near it in Earth’s sky.

Though ISON will be bright as it nears the Sun, the problem is that it may be obscured by the Sun’s brightness. It should be about 4.4 degrees from the Sun at Perihelion (about 9 widths of the Sun) .

National Science Foundation ISON Photo Contest

From the National Science Foundation Website: Win $2,500 in an ISON Comet Photo Contest . . .

Comet ISON Photo Contest

ALL EYES ARE ON COMET ISON. Around the world, astronomers are buzzing with anticipation over the approach of Comet ISON. On Thanksgiving Day 2013, the icy visitor from the outer solar system will skim the sun’s outer atmosphere and, if it survives, could emerge as one of the brightest comets in years.

Bright comets excite astronomy enthusiasts like few other sky events, and so there will be enormous interest in viewing the comet among amateur astronomers and the public at large. ISON could be as bright as the planet Venus in the early morning sky.

The National Science Foundation, Division of Astronomical Sciences along withAstronomy magazine and Discover magazine, is holding a unique contest centered on capturing images of the expected bright Comet ISON (C/2012S1).

This comet will be exceptionally bright, reaching naked-eye visibility by the end of October and peaking in brightness just after Thanksgiving, when it draws closest to the Sun. it will remain visible to the naked eye into early January 2014.

We challenge photographers, amateur and professional, to explore the Comet through cameras & tripods, piggyback cameras or through the scope. The competition is an opportunity for photographers to consider the Comet in a different light.

Continue reading

Oort Cloud

The Oort cloud is a hypothesized spherical cloud of icy predominantly icy objects that may lie roughly 50,000 AU (astronomical units), or nearly a light-year, from the Earth and Sun, past the planet Pluto. This places the cloud at nearly a quarter of the distance to the nearest star to our Sun. The edge of the Oort cloud defines the outer limit of our Solar System. Objects in the Oort cloud are largely composed of ices, such as water, ammonia, and methane.

Astronomers believe that the matter composing the Oort cloud formed closer to the Sun and was scattered far out into space by the gravitational effects of the giant planets early in our Solar Systems history.

Astronomers also believe that the Oort Cloud is the source of all long-period Comets, such as ISON. Since the outer Oort cloud is only loosely bound to the Solar System, it is easily affected by the gravitational pull both of passing stars and of the Milky Way itself. These forces occasionally dislodge comets from their orbits within the cloud and send them towards the inner Solar System. Again, this is the theory behind ISON, which is believed to be a comet never before seen.

Please refer to the Oort Cloud Link on Wikipedia for more detailed information.

Comet History

cIn 1577, the Dutch astronomer Tycho Brahe began making the first real observational studies of comets by observing a bright comet that appeared in Earth’s skies. Brahe concluded that the comet had to exist outside of the Earth’s atmosphere due to the fact that the position of the comet in the night sky appeared not to change in relation to an observer’s location on the Earth. This information suggested that the comet had to be very far away.

Sir Isaac Newton became curious about comets and began to apply his laws of gravitational motion comets. His conclusions stated that comets were accelerated by gravity towards the Sun and that they move in orbits about the Sun that are either parabolic or highly elliptical in nature. We now know today that this is relatively accurate; cometary orbits are periodic in nature, with periods as long as millions of years or as short as that of Comet Encke, which has an orbital period of 3.3 years.

 
Figure Two: Comparison of Planetary and Comet Orbits

Edmund Halley (1656 – 1742) extended Newton’s study of comets. He took interest in a series of very bright comets that appeared in 1531, 1607, and 1682; Halley noted that the orbits of these comets were very similar and that all three could actually be the same comet with an orbital period of 76 years. His prediction proved correct when he accurately predicted the return of the comet in 1758. In his honor, the comet was named Halley’s Comet. The last appearance of Halley’s Comet took place in 1986, and it is not scheduled for a return visit until the year 2062.

The exploration of comets has, in recent decades, taken stellar leaps, with specific missions to visit comets. This has been accomplished through the use of interplanetary probes that are launched from the Earth and rendezvous with a comet. The first such encounter took place in 1985 when the U.S. satellite International Sun-Explorer was moved from its set orbit so that it could perform a flyby of the comet Giacobini-Zinner. The spacecraft, now named International Comet Explorer (ICE) passed about 7800 kilometers behind the comet, traveling through the tail on September 11, 1985.

When Comet Halley passed close to the Earth in 1986, six probes were set to gather information about the comet. Two craft, the U.S. ICE probe and a Japanese craft called Sakagaki observed the comet from a distance of many million kilometers while a second Japanese probe, Suisei, passed to within 1 million kilometers of the comet. The other three spacecraft were targeted to gather data on the nucleus of the comet. Two Soviet probes, VEGA 1 & 2, encountered the cometary nucleus on March 6 and 9, 1986, respectively; they both passed into the comet’s atmosphere and passed to within 8000 kilometers of the nucleus. The final spacecraft, a European probe named Giotto, made an even closer rendezvous with the nucleus on March 14, 1986, passing to within 605 kilometers of the nucleus. At this close proximity, Giotto was actually able to beam back images of Halleys nucleus…

Comets

comet is an icy solar system object that, when passing close to the Sun heats up and begins to spew out gasses outgas, displaying a coma or tail. These effects are due to the effects of solar radiation and solar wind on the center of the comet.

Comet centers (or nuclei) range from a few hundred yards/metres to tens of miles/kilometres across and are composed of loose collections of rocky particles, ice, and dust. The tail is much larger, stretching generally from 600,000 to 6 million miles ! Many comets are large and bright enough to be seen from earth.

Comets have a wide range of orbital periods (length of an orbit around the Sun) ranging from several years to several millions of years. Their orbits are very unique in that they approach very close to the Sun — creating their spectacular celestial “streaking” images.

Short-period comets originate in the Kuiper Belt which lies beyond the orbit of Neptune. Longer-period comets (like ISON) are thought to originate in the Oort Cloud, a cloud of icy bodies extending from outside Pluto to halfway to the next nearest star.

Comets are distinguished from asteroids by the presence of an unbound atmosphere surrounding their central core. This atmosphere has parts termed the coma (the central atmosphere immediately surrounding the nucleus) and the tail (a typically linear section consisting of dust or gas blown out from the coma by the Sun’s light pressure or outstreaming solar wind).

As comets orbit and pass close to the Sun, they lose some of their ices and dust, and over time can be seen as becoming “extinct” and resemble small asteroids. Asteroids have a different origin, having formed inside the orbit of Jupiter rather than in the outer Solar System.

Comet ISON’s Green Color

Recent photographs of ISON have revealed a greenish hue. The color comes from the gasses surrounding the comet’s nucleus (probably cyanogen and diatomic carbon), which are both gasses that glow green when illuminated by the Sun’s light.

The greenish color is a good sign of things to come, as ISON approaches the Sun, signaling that ISON is becoming more active as it approaches the Sun, which is a good signal that it may be quite visible in the coming weeks.

Comet ISON on October 4, 2013 as seen over Arizona, viewed with a 12.5" telescope, over an hour exposure time. Credit and copyright: Chris Schur.

 

 

My Personal Astronomy Journey

I’ve personally been interested in Astronomy since I was a small boy. I can still vividly remember running back and forth on the streets of New York City amazed that the moon would “follow me”. Years later I understood this simple phenomenon scientifically, but I’ll admit it was more fun running back and forth an wondering what was happening.

I also remember back in Junior High School when there was a full solar eclipse. The whole neighborhood was out with their pinhole box viewers marveling at the phenomenon.

What I also remember about that day was then when the eclipse began, the animals and bird all went a bit “nuts” and started barking and tweeting, as if they knew that something magical was happening.

In high school, I dreamed of becoming an astronaut, but alas chose engineering and then business. Still, I’m always aware of the moon’s phases, meteor showers, eclipses, the solstices, and of course the rare comets visible to the naked eye, and other objects I can see with my telescope or binoculars.

I hope we can all take time each day to remember that without the Sun and Moon we wouldn’t exist. That without the stars, we’d think we were alone in the universe. And I hope it reminds us that we are each just a small part of a world of wonder.

KZDEGRMPXHSR

ISON Disintegration Prediction Article

The following article appeared in The Space Reporter on October 20, 2013. According to images taken from Nasa’s Hubble telescope, ISON is still looking good …

Photo of dazzling comet ISON challenges disintegration prediction By Max Sonnenberg, The Space Reporter 

Here’s a short excerpt — Click Here for Full Article

“According to NASA, comet ISON is still intact. The space agency reached this conclusion after seeing a photo snapped by the Hubble Space Telescope. Some have predicted that the delicate icy nucleus might disintegrate as the sun heats it. The space agency notes that ISON is expected to journey closest to the sun on November 28.

According to NASA, ISON’s solid nucleus is uncertain in this images (snapped on October 9) because it is so tiny. However, had the nucleus disintegrated, the space telescope would have likely detected evidence of numerous fragments. Plus, the coma encircling the comet’s nucleus is balanced and smooth…. “

Photo of dazzling comet ISON challenges disintegration prediction

YES — there’s a Comet

I’m still amazed how few people know there’s a Comet in the sky right now, that just passed Mars streaming towards the Sun. I must tell at least 10 people a day, and I’m lucky if 1 has any idea of ISON.

Separately — I just bought a new puppy — an Australian Shepherd. I named him Comet!! This also gives me to opportunity to talk about ISON since people want to know where my dog’s name came from.

“Coincidently??” He happens to have a white comet-like streak on the top of his head. I named him Comet in honor of ISON — and truly noticed the streak afterwards. Interesting …

It will always we a great story of how he was named — hopefully by then, people will remember comet ISON too.

KZDEGRMPXHSR