June 10th 2008,
Welcome to WordPress.com.
This is my first post.
Today I visited and then downloaded the Microsoft WorldWide Telescope
and I viewed the Skies and saw the stars and galaxies up close and it was amazing, Indeed there must be a Creator, not as I understand Him, much much much more than I can ever imagine or conceive, so I better not imagine and only wonder at the size of the Universe only and see how large and huge it is galaxies upon galaxies.
Allah is great.
Your inquiry is definitely in the minds of many scientists who are trying to obtain a good estimate for the number of galaxies in the universe. The methods used to achieve such number varies, and therefore, the results would vary, too. Also, as new and improved technology becomes available, astronomers can detect fainter objects that were not seen before. These objects that have come into view will in turn change the estimated number of galaxies.
For example, in 1999 the Hubble Space Telescope estimated that there were 125 billion galaxies in the universe, and recently with the new camera HST has observed 3,000 visible galaxies, which is twice as much as they observed before with the old camera. We’re emphasizing “visible” because observations with radio telescopes, infrared cameras, x-ray cameras, etc. would detect other galaxies that are not detected by Hubble. As observations keep on going and astronomers explore more of our universe, the number of galaxies detected will increase. For more about the Hubble Space Telescope, check out this web site:
Number of visible stars put at 70 sextillion
Friday, 25 July 2003
The universe contains about 70 sextillion – or 70 thousand million million million – observable stars, according to the most accurate estimate yet made of the number – a figure that far exceeds all previous estimates.The calculation was made by a team led by astronomer Dr Simon Driver of the Australian National University in Canberra and announced this week at the 25th General Assembly of the International Astronomical Union in Sydney.”Even for a professional astronomer used to dealing in monster numbers, this is mind-boggling,” said Driver. “This is not the total number of stars in the universe, but it’s the number within range of our telescopes. The real number could be much, much larger still – some people think it is infinite.”Even so, 70 sextillion is greater than the estimated number of sand grains on all the world’s beaches and deserts – about 10 times more.The team – which included Dr Jochen Liske from the Royal Observatory Edinburgh, Dr Nicholas Cross of Johns Hopkins University, Professor Warrick Couch from the University of New South Wales in Sydney and Dr David Lemon from St Andrews University – did not physically count the stars.
Using some of the world’s most powerful telescopes, they instead took a representative sample by counting all the galaxies in one small region of the universe closest to Earth. By measuring precisely how bright each galaxy was, they were able to estimate how many stars it contained and then extrapolated this out to the whole region of the universe visible through telescopes.
The team believes its estimate is 10 times more accurate than any previous one because it combines the best counts of galaxies ever conducted with the most modern cosmological measurements of the geometry of the universe.
The calculation was made as part of the world’s largest galaxy survey, the Two-Degree Field Galaxy Redshift Survey, results from which were also presented to the meeting this week. The survey, run by the Anglo-Australian Observatory in rural New South Wales, aims to measure the distances of 250,000 nearby galaxies.
Driver noted that the vast majority of stars are too dim to see with the naked eye, which can pick out only around 5,000 stars from even the darkest places, and only 100 or so in the middle of a big city.
But he argues that most stars probably have planets, a fraction of which probably have life: “But they are very, very far away. It’s not so much a question of whether other life exists, but whether we will ever be able to contact them, given the massive distances involved.”
Last year, Dr Charles Lineweaver and doctoral student Daniel Grether of the University of New South Wales in Sydney, calculated that our Milky Way galaxy contains about 300 billion stars, of which about 30 billion are like our Sun, and at least 1.5 billion theoretically have orbiting planets the size of Jupiter.
In 1999, observations by NASA astronomers, using the Hubble Space Telescope, suggested that there are 125 billion galaxies in the universe.