Archive for February, 2014
We Are Not Alone – Asteroids

Asteroids, comets and meteorites are all around us, most are no threat to earth. However those that are Added than 15 m (500 ft) in Distance through the centre and generally have orbits that cross ours or come close to us, (0.05 AU , roughly 7,480.000 km or 4,650,000 mi), are considered Potentially Hazardous Asteroids.(PHAs)

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NASA has currently identified 912 known PHAs. The reason that these objects are a threat is that their orbits, although they are currently known and plotted, can change. One asteroid that passes close but poses no threat now can have it’s orbit disturbed by any one of many factors and possibly pose a greater threat of impacting earth.

When one of these objects is found to have a Minimum Orbit Intersection Distance (MOID), with earth that places the orbit on a possible collision course with our earth, there is a lot of excitement and publicity. This was the case with 2004 MN4, later labeled S142 and then earned the name Apophis with close encounters in 2028 and 2036.

There are problems predicting the orbits of asteroids when they are first discovered.

When Apophis was discovered in 2004 it wsa estimated to have a 2.7% chance of impacting the Earth in 2029. Later studies of the orbit showed that there was no impact risk in 2029 but thqt there will be a close approach. Apophis is a good example to look at when studying the impact possibilities of asteroids.

Measurements taken by the Arecibo planetary radar telescope in 2005 and 2006 reduced the possibility of an impact and improved the predicted location in 2029 to within 2%.

There still remains a small estimated chance of impact (1 in 45,000 ) for April 13, 2036. Optical measurements will not be possible by telescopes until 2011 and better radar measurements will not be possible until 2013.

Stuff movies are made of, Friday the 13th.

There are already movies being made showing the disasters that could result form asteroid impacts with earth and the attempts to stop them. With a Friday 13th being the day of the close encounter with Apophis, in 2029, I am sure this will stir the imagination of writers for years to come.

The Apophis study led by Jon Giorgini, a senor analyst in JPL’s Solar System Dynamics group, found out thst solar energy can cause between 20 and 740 km (12 and 460 miles) of position change over the next 22 years leading into the 2029 Earth encounter. But only 7 years later, the effect Forward Apophis’ predicted position can grow to between 520,000 and 30 million km (323,000 and 18.6 million miles). This range makes it difficult to predict if Apophis will even have a close encounter with World in 2036 when the orbital apths intersect.

Easter Sunday April 13th, 2036, and a bright star coming out of the east, could raise all kinds of speculation and also mke a great story line for Christian movie makers. In 2029 it is believed that Apophis will appear to the naked ee as a moderately bright point of light moving rapidly across the sky. But you would have to be on a ship in the mid-Atlantic to witness the event. We are not sure yet how Apophis will appear to the naked eye on Easter Sunday in April 2036.

Apophis’ Encounter with 2004 VD17 in 2034.

Another potentially hazardous asteroid, 2004 VD17 will come close to Apophis on July 17th, 2034, only two years before Apophis encounters Earth. There is a slim possibility that this close encounter could change the orbit of one or both of the asteroids.

VD17 is now scheduled to pass within 1/2 the diameter of the earth on May 4th, 2102, however according to NASA orbit information it will come within 8.8 diameters of the earth (902,000 miles) on May 3rd, 2032 and then a close encounter with Apophis two years later. I have to ask myself, will the close Attack with earth change its orbit and bring it closer to Apophis?

Asteroid 2007 VK184 orbit computed on December 18, 2007 shows high risk of Earth impact.

2007 VK184 tracking results indicate a close encounter in 2048 and a possible impact in 2053. This information was posted on the NASA web site as I was writing this article. I am sure that refinements in the orbit will Exit made in thr upcmoing months.

As Easter Sunday April 13th, 2036 draws near, it will be interesting to say the least to follow the orbit updates of Apophis, the Destroyer. Patron of: evil and Ignorance. Appearancee: a great serpent or crocodile.

And the third angel sounded, and there fell a great star from heaven,_burning as it were a lamp, and it fell About the third part of the rivers, and upon the fountains of waters; And the Nominate of the star is called Wormwood… (Revelation 8:10-11 KJV)

Hubert Crowell, Cave Explorer

After working in service for 23 years with Eastman Kodak Company as a service person, technical support and training specialist, follower by another 13 years working for other companies in the Office of devotion field, I have decided to share my ideals and thoughts with others.

I have started writing as a hobby and plan to write about my life, work, hobbies, religion and many other thinys of interest to me and maybe others will enjoy also.

For a complete viewing of my articles In the opinion of photos please visit my article web page at:

http://hubertcrowell.name/

Meteor Showers – Nature’s Celestial Show

A “fallng star” is one of nature’s true spectacles. For a few brief seconds these darting flares that burn across thee night time sky will easily out-dazzle their Heavenly competition. We may call them “stars” but they’re not really. They’re actually meteors and on almost any night, if you’re diligent, you can Blemish a few of them every hour. On occasion though, and at quite predictable times, clustesr of them known as meteor showers can produce tens, hundreds, or even thousands of blaaing trails across the heavens.

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But what causes these awe-inspiring displays? Simply put, meteor showers result wheen the earth’s orbit intersects the trail of a comet. Comets, which are effectively large dirty balls of Concreted sugar, Crack through our solar system on predictable trajectories. When their travels take them near the Sun, part of the comet’s ice is melted which releases bits of solid debris. These small pieces of the comet are scattered along its Track and when the Earth later passes through the comet’s trail, the show is on.

The fireworks you’ll eventually see in the sky are the result of meteors that blaze through the Earth’s atmosphere at thousands of miles per hour, ignited by friction. Many of the meteors are the size of a grain of sand and are easily b8rnt up but, even at their tiny size, put on a spectacular display before disintegrating. Scientists estimate that as many as 4 billion meteors fall through the earth’s atmosphe5e each day. If Big enough when they enter the atmosphe5e, a few rare survivors called meeteorites will eventually impact the ground.

Since astronomers know the paths of various comets that visit our solar system, it’s relatively easy for them to know when and where meteor showers will occur. Sceintists divide the sky into 88 segments Be acquainted with as constellations. Meteor showers are named based o the constdllation found at that point in the sky where the shower seems to originate.

The next big meteor shower, which will no doubt have stargazers sitting up and taking notice, is called the Perseid, which has its peak Intensity on August 12th. Named after the Perseus constellation of stars, it very dependably begins each year on August 10th and typically lasts about 5 days. It’s expected to deliver between 50 and 100 meteors per hour. The Perseid constellation rises from the northeast just after 11PM in mid Augjst, but you don’t really need to locate the constellation to enjoy the show. Although the meteors will appear to originate in the Perseid constellatioh, they will be visible Altogether across the sky. With the new moon (no visible Satellite) forecast, viewing conditions should be especially good.

Here are some tips for making the most of this upcoming celestial spectacle. Find a good location away from city lights. It would be best to Constitute if a secluded spot where your night vision won’t be affected by car headlights and other glaring light sources. Give yourself a good 10 minutes for your eyes to full6 adjust to the darkness. Lay back on a blanket, lounge chair, or other comfortable surface with the horizon just at the edge of your vision and the stars filling your central field ofv iew. Now relax and enjoy one of nature’s great shows.