Nilesh's Weblog

October 19, 2003

What you see is not what you thought

It is said that the Chinese astronaut Yang Liwei, on his recent space sojourn did not see the great wall of China from up. Many of us were made to believe that the only man-made structure visible to the naked eye from Moon was the Great Wall of China. And how gullible we were! The fact is, no man-made structure is visible to the naked eye from Moon. However many man-made things are visible from Earth's orbit. If you have a pair of binoculars, you can even see an aeroplane reflecting sunlight off its back or an artificial satellite floating below you! The adjoining is a photo of the pyramids taken with a digital camera and an 800mm camera lens. You can even see the Great Wall. But now many parts of the wall have been covered by sand and it has become difficult to spot it.

August 05, 2003

Rendezvous with the Green Men

Be prepared for the closest view of Mars in more than 50,000 years. Come August 27 and Mars will be the third brightest object in the sky, after Moon and Venus. Contrary to rumour mills, Mars won't be as visible to the naked eye as the Moon. The highest magnitudes of Moon and Venus are -12.7 and -4.0 respectively (The more negative the magnitude, the brighter the object). That of Mars will be only -2.9 on August 27. However, it is said that with the help of a 75-magnitude telescope, the red planet will appear as large as the moon, an event worth capturing on my camera. That remains to be seen. Mars has had its share of urban legends, the most famous being The Other Face. Know about the position of Mars here. Check this link for all activities related to Mars in 2003. You may also want to know more about perihelic oppositions.

May 15, 2003

Interplanetary Internet

It isn't a dream. It isn't a reality as yet. But the IPN may soon be real given that Vinc Cert too is backing the idea. As soon as 2005. It will connect the various space ships and planets of our solar system. IP address ranges have already been assigned to all the planets and spaceships in our solar system. The IPN will have a lot of latency because of the large distances. Even light takes 8 minutes to reach the earth from the sun. So IPN would be more suited for email-like applications, atleast initially, till we think of better ways to transmit information.

March 12, 2003

The last few seconds

And now the timeline that led to the space tragedy of the century - The CAIB has released an excel file showing the second-by-second view of the internal working of the space shuttle which eventually blew up in the sky. Too technical but that's what I like. Forget trying to decipher the abbreviations used in the document. I did try to search around, but without success. This was on space.com.

December 04, 2002

Analemma

What is an analemma? Well, if you photographed the sun once a week at the same time of day for an entire year, you would have a photo of the analemma, the sun's apparent path on the sky over the course of a year, which looks like a figure-eight.

The resulting photo is by your side. Ideally the shape of the figure should have been a slanted line across north-south directions. Then how does one explain this? There are two phenomena responsible for this `Analemma' - First As we all know, the earth is tilted at 23.5 degrees. This causes the seasons and the solstices (Uttarayana & Dakshinayana, as we call it). This causes the movement of the sun in the north-south direction. Second Earth's orbit is elliptical, not circular. Hence Earth's orbit speed is not constant. It varies periodically. This causes the additional east-west movement of the sun at the same time on different days and that we can observe. On some days of the year, at 12 noon, the sun is not exactly at the zenith, it is either ahead or behind schedule.

Isn't that interesting enough to take up as a photography project spanning one year? Yes, sure. But if you are still confused and need some animation/movies to get convinced, go to analemma.com.

December 03, 2002

Heavens Above

I have often seen semi-bright objects moving slowly across the sky at dawn or at dusk. Earlier I used to think those were jet planes moving at very high altitudes. I was wrong. I discovered that they are none other than artificial satellites. They are more visible at dawn/dusk because at that time the slant sun rays reflect from their metal bodies and reach us. Although they are quite visible in broad daylight too! There is actually a site dedicated for guidance on how to spot satellites in the sky, giving their current positions and predictions of future sightings. It is called Heavens Above. So if you want to catch a glimpse of the ISS or the Iridium from mother earth, here's your chance.

December 01, 2002

Get your facts right

If you think there is no gravity in space or that meteors are heated by friction as they hurtle down the atmosphere, here is a great top five myths buster from space.com. Also the ten most confounding cosmic questions.
And all you falling-rocks-loving-palm-pilot-sporting people, get this free Palm app - Meteor Counting and Observation Program. So what if the Leonid showers are over, there is always the next time.

November 11, 2002

Changing Sides

According to this Guardian article, the Earth's magnetic poles might just change positions. Compasses around the world will point to the wrong pole. North will become South and East will become West. The indicator to this has been the decline in strength of the Earth's magnetic field and the rate of which is speeding up. Don't worry, it is still about a millenium or two away. It was about 780,000 years ago that the last flip occurred. And what exactly will be the effect on us? Nothing to mention actually, except that during the flip, the magnetic field of earth will shut down temporarily and we will be exposed to EM radiation from space! And yes, satellites will suffer. Probably your TV screen, The Internet, phone lines will remain dead for a period ranging from a week to about a 1000 years! ;-) If you are really alarmed by that, just take solace from the fact that our star Sun flipped its magnetic poles last year. As if you noticed the difference... Oh, the sun seems more hotter now.... :-). In other news, at place under South Africa, the magnetic field is pointing in the opposite direction than the rest of the world. The size of this area has been growing for a hundred years now. Learn about magnetic cycles here.

November 03, 2002

The Top 5 Tele's

The telescope is the best tool man ever had to explore the heavens. Telescopes have made technological advancements by the multiple, right from the 3x magnification Spyglass used by Galileo to the modern day Hubble boasting of a 2.4m mirror. Space.com has this nice article telling us about the top five telescopes of all times.

To Saturn and Not Beyond

After the Jupiter Flyby on 30/12/2000, the Cassini spacecraft has taken the first shots of Saturn. Saturn and its moon Titan is the destination for the Cassini-Huygens mission. The spacecraft is still about 2 years away from its entrance into Saturn's orbit and in the fifth year of its seven year journey to the ringed planet. Find the present position of Cassini here

October 08, 2002

Quaoar

It is the newest 'planet' of the solar system. It is one-tenth of the size of Earth. Its orbit around the Sun takes 288 years. Its of the size of all asteroids in the solar system put together. Called Quaoar (Kwah-o-wahr), this KBO dwells in the Kuiper belt outside Pluto. This belt is the remains of the bits and pieces left after the planet formation. It is a breeding ground for comets encircling the sun. You can read more about the newest addition to the solar system here, here & here.

June 10, 2001

Powers of Ten

View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree just outside the buildings of the National High Magnetic Field Laboratory in Tallahassee, Florida. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons. At micro.magnet.fsu.edu