Category Archives: fun

Apophis to Impact Earth in 2036?

In 2004, astronomers at Kitt Peak Observatory in Arizona, USA discovered a near earth asteroid, dubiously named 99942 Apophis. The asteroid is about 200 m across in diameter. It became famous for being an asteroid with a rating of 4 on the Torino Imapact Hazard scale. Since 2006, the asteroid had been demoted to 0. However recent studies into the asteroid’s orbit has questioned the accuracy of this rating. Scientist in Russia think that there is a very real chance this asteroid will impact earth in 2036.

This observation has been refuted by NASA. According to Donald Yeomans, director of NASA’s near earth objects office claims that the probability of impact is currently 1/250,000.

Apophis will come within 5 earth radii distance of the earth in 2029. However if the asteroid passes within a region of space called the “keyhole” during this period, the orbit might change enough to cause impact with earth.
The predicted date of impact is April 13, 2036.

Impact Consequences
Apophis carries a massive Kinetic energy of 5.1e+02 Mega Tonnes of TNT equivalent. To put numbers in perspective, the Hiroshima nuclear bomb had a 20 Kilo tonnes yield.

However from preliminary calculations we did based on this article, a Apophis class asteroid will create a 4 Km wide impact crater on a direct hit.


Predicted possible impact locations of Apophis

TOTAL SOLAR ECLIPSE JULY 22nd 2009

Total Solar Eclipse 2009, Amateur Astronomers Association Delhi

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Mark your calendars folks, its surya-grahana time in India again. Come July 2009 the moon will eclipse the sun as seen from India, Bhutan,Bangladesh,China, Japan and the Marshall Islands. Its going to be the longest solar eclipse for over a century and guess what, this time the path of totality passes through India. This eclipse pass over India comes after almost a decade. The last two eclipses happened in 1999 and 1995.

Totality

The eclipse begins on the 22nd of July 2009 at around 5:30 am IST in India and spends almost two hours passing the subcontinent. The path of totality will pass through central India passing over Surat, Ujjain, Baroda, Bhopal, Patna, Darjeeling, and Dibrugarh in the far east. Rest assured the Bohemians will be out there somewhere chasing the eclipse.!!!!



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Circumstances of the Eclipse
For a full list of Eclipse circumstances CLICK HERE

Eclipse Safety : Observing Eclipse Do”s and Don”ts

warning Before we go on I must warn you to NEVER EVER look at the sun especially the PARTIAL PHASE through unprotected eyes or homebrewn filtering mechanisms.

The use of homebrewn filters is recommended to seasoned astronomers only who understand the risks involved! There are however very simple ways to observe an eclipse without putting your eyes in harm”s way

One of the simplest method to observe the sun safely is through a pinhole projection camera. This can be used for viewing the partial phases of the eclipse. During totality however, it is perfectly safe to watch the eclipse naked eye.

To learn how to make a pinhole camera CLICK HERE

Alternatively you may use a solar filter
solar filters

The first thing you must remember is that the human eye has no nerve endings, so if you burn your retina, it will not hurt. 😛 , which is all the more reason that caution is advised while observing the sun

It is never safe to look at a partial or annular eclipse, or the partial phases of a total solar eclipse, without the proper equipment and techniques. Even when 99% of the Sun”s surface (the photosphere) is obscured during the partial phases of a solar eclipse. This is primarily because nearing totality the ambient light levels become so less that our pupils dilate and the iris tries to allow in more light into the eye.

During the partial phase any surge in sunlight, like the one seen during a diamond ring formation can cause excessive solar radiation entering the eye and causing a burn on the retina.


In spite of these precautions, the total phase of an eclipse can and should be viewed without any filters whatsoever. The naked eye view of totality is not only completely safe, it is truly breathtaking

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UPDATES

Update: May 29d 2009
AAAD Observation Plans

Update: March 3rd 2009
The Solar Eclipse: Facts, Fiction and Pregnant Women
Update: March 2nd 2009
Average Cloud Cover along the Central Line of the Eclipse