Plus
Mars approaches
By Ruwanthi Herat Gunaratne
People all over the world will
have an opportunity to get up, close and personal with Mars, the red planet, this
month.
Earth and Mars are rapidly
converging. On August 27, 2003, the date of closest approach, the two worlds will
be 56 million km apart. That's a long way by Earth standards, but only a short
distance on the scale of the solar system.
"It is a rare type of celestial
phenomenon," says Colombo University’s senior physics lecturer Chandana Jayaratne.
"On August 28, Mars will be at Opposition." Opposition means that the Sun, Earth
and Mars are in a straight line with Earth in the middle. Mars and the sun are
on opposite sides of the sky. When Mars is at opposition and at perihelion at
the same time, it is very close to Earth.
When Mars is at perihelion,
it is at its closest approach to the sun. (The orbit of Mars, like that of all
planets, is an ellipse, so the distance between the sun and Mars varies.)
Mars comes to opposition about
once every 26 months. But because of the elliptical orbits of Earth and Mars,
not all oppositions are created equal. The 2003 opposition will be superior to
the others because Mars will be very near to its closest point to the Sun, called
perihelion, when it arrives at opposition. This is also when we are overtaking
Mars in our respective orbit.
This is not to say that you'll
suddenly notice little green men for which Mars is "supposedly" famous. You will,
however, notice an incredibly bright, colourful light in the sky. And with a telescope
of moderate size, an observer might make out hints of surface features.
"Human fascination with Mars
began long years ago," explains Dr. Jayaratne. "In most cases, people were afraid
of the planet as it was red in colour." The red is associated with the abundance
of iron oxide rusts found on Martian soil.
The invention of the telescope
in 1610 revealed that the Martian surface contained a number of canals. As a result
of this discovery, man came to the natural assumption that there was intelligent
life on the planet. Space missions made to Mars around the 1970s, however, gave
no evidence of life or water. But further investigations led to the conclusion
that Mars did possess water and perhaps may still have water beneath the surface
that may come out from time to time like volcanic eruptions. It would originate
from the surface, flow freely like a river and disappear once again into the planet's
interior.
"Earth will soon be overcrowded
and scientists have reached a point where they are looking for space to relocate."
Only Earth's moon and Mars may provide the solution in the form of offering accommodation.
"But Mars remains on top of the list because it is a planet and it possesses water."
More recent discoveries revealed
that two ice caps on the Northern and Southern Poles comprise frozen water (ice)
and not carbon dioxide as presumed. "That was one of the problems associated with
Mars, as its atmosphere comprises carbon dioxide and not oxygen like on earth
and also because the atmosphere is not as dense as that on earth." But solutions
were suggested. "One was the introduction of algae or a special green plant, in
the hope that through photosynthesis, oxygen will be produced."
This Wednesday, we will be
able to afford ourselves with a view of our most probable 'new home'. "This is
the closest that Mars has come to our planet in nearly 60,000 years. A similar
event last occurred on September 12, 57617 BC and the next event is due to occur
on August 28, 2287."
The closest approach takes
place around 3:52 p.m. Sri Lanka time. On the 27th night the reddish point of
light in our night sky will appear more than six times larger and shine some 85
times brighter than it has appeared before, said Dr. Jayaratne
Officially, Mars will reach
a magnitude of minus -2.9 on this day on a scale used by astronomers to denote
brightness. (Lower numbers indicate brighter objects, and negative numbers are
reserved for the brightest. The full moon is -12.7 and the sun is -26.7)
What is the best place to view
Mars? "It will be visible throughout the country, as long as the skies remain
clear." Night observation camps have been planned to show Mars during this period
to the general public using large telescopes. "Everyone is welcome," says Kushlan
Chandrasekera, President of the Mathematical and Astronomical Society of the University
of Colombo.
Take a good look
The best viewing is always
under the darkest skies. Whether you view the night sky with your naked eye, binoculars
or a telescope, here are a few tips to enhance the experience.
* Turn off any lights you can.
Allow 15 minutes or more for your eyes to adapt to the darkness.
* One thing you can't control
is the atmosphere. Even a cloud-free night isn't always great for viewing. When
you look directly overhead, you're peering through about 7 miles of the troposphere,
the densest portion of Earth's atmosphere. The result can be blurry stars.
* Turbulent air can have an
effect, too. It makes objects appear to jump around or twinkle. Telescopes will
yield better results when the atmosphere is calm.
Source: www.space.com and www.science.nasa.gov
Observation Camps
August 25, 26 and 29
Colombo University (Next to
the Observatory Dome):
From 7:30 p.m. to 11 p.m. Using
the second largest telescope in the country.
August 27
Planetarium: From 7:30 p.m.
to 5:30 a.m. (28th Morning)
In case of cloudy skies, a
visual presentation will be held inside the Planetarium.
August 27 and 28
Arthur C. Clarke Institute
of Modern Technologies, Katubedda, Moratuwa.
From 7:30 p.m. to 11:00 p.m.
Using a 45 cm reflector telescope,
the largest telescope in the country.
Copyright © 2001 Wijeya Newspapers Ltd. All rights reserved.
Webmaster Editorial