Saturday, February 26, 2005

Looking Skyward

What to look for over the horizon. Orion still at its best commanding most of the sky. Jupiter is bright enough to be seen. It rises somewhere around 10pm . If you look out today, Its just under the moon. Cannot be missed. Looks like a real bright star. When the Sun sets you can see Sirius star in the constellation Canis Minor, ofcourse until it is set aside by Jupiter. Also if you look Northward, there is the Saturn. Its probably in the consellation Gemini. Look at Sirius and look Northward until you pass Orion completely. Need a little trial and error to locate though.

Nothing much to share tonight, so me signing off


Tuesday, February 22, 2005

The Age old question back in focus

Does Mars still have life? This question is raised again today by the European researchers handling the Mars Express orbiter.
A lot of methane at three crucial places on Mars along with a theory that underground water is still present suggest the possibiltity that there might still be microorganisms living under the surface which are the source of methane that we see. And we thought this matter was closed. Mars used to hold water for a long time ages ago and due to the core cooling down it caused gravity to cease and water to disappear into space along with microorganisms. Though it still a mystery whether microbes can do this trip in space and reach earth, it can be a possibility that we technically are Martians. Since the first time since Voyager sent Mars images and Viking orbiter images, Mars was always the greatest contender to find water. Since this research has ended in success still the enigma of Mars will never leave us. It still brings in something interesting and mysterious at the same time.
Mars research has not ended yet and there is still a lot to be discovered, possibly life. THis can be the greatest discoveries of the century.

Friday, February 04, 2005

The Sirius Star -Joe Rao

As darkness descends this week, cast a glance over toward the east-southeast and you will see a brilliant, bluish-white star scintillating just above the horizon. You’ll be looking at the brightest star in the sky, the Dog Star, Sirius.

Sirius is the brightest star of the constellation Canis Major, which is Latin for the "Greater Dog." Among all the visible stars, Sirius is one of only four stars of negative magnitude (-1.44). The lower the figure of magnitude, the brighter the star.

Of the 21 brightest stars, twelve are considered to be of first magnitude, and five are of zero magnitude. But only Arcturus, Alpha Centauri, Canopus and Sirius are bright enough to be assigned a magnitude value lower than zero, or of a negative magnitude.

According to Burnham’s Celestial Handbook other names for Sirius include "The Sparkling One" or "The Scorching One." The star normally appears a brilliant white with a tinge of blue, but when the air is unsteady, or when it is low to the horizon it seems to flicker and splinter with all the colors of the rainbow. At a distance of just 8.7 light years, Sirius is the fifth-nearest known star. Among the naked-eye stars, it is the nearest of all, with the sole exception of Alpha Centauri.

Many astronomy books suggest you can locate Sirius by using the belt of Orion; that the belt points southeast directly toward Sirius. Of course, that is absolutely true (in fact, following the belt in the other direction takes you to another first magnitude star, Aldebaran, in Taurus, the Bull). Of course, being the brightest star in the sky has its advantages. It’s almost impossible to overlook as it gleams in the southeastern evening sky these frosty evening.

If you’re still uncertain about what you are seeing and want to make a positive identification, then by all means, use Orion’s belt to verify that you’re indeed looking at Sirius.

Sirius will be due south between 9 and 9:30 p.m. local time all of this week, and doesn’t set below the west-southwest horizon until after around 2:15 a.m.

Over thousands of years, Sirius appears to move in a wavy line across the sky. In 1862, Alvan G. Clark first saw Sirius B, also known as "the Pup," the companion star responsible for the wiggle. Sirius B is only one ten-thousandth as bright as Sirius A, but by 1914, spectroscopic observations had demonstrated that its temperature was about the same.

From physical laws it follows that B emits the same amount of light per unit surface area as A, therefore to be so dim it must be very small. Later calculations have shown that A has just over twice the mass as our Sun, but B has nearly one solar mass. Since it is so small, B must be exceedingly dense.

In fact, it packs 98 percent of one solar mass into a body just 2 percent of the Sun’s diameter. To do that, Sirius B must have a density 90,000 times that of the Sun.

Unbelievably, just a teaspoon of this star’s material would weigh about 2 tons!