Assignment 6. Modern Astronomy

Assignment 6. Modern Astronomy


Before the invention of the telescope, all human knew about the universe is got from the observatory of our naked eyes. When Galileo applied his innovated telescope to cosmology in 1610, he showed a world a much clearer picture of this amazing universe.[1] The great discoveries that Galileo made with his refined telescope include the Moons of Jupiter and the Phases of Venus.

Graph 1 Galileo's drawings of phases of the Moon



During the following years, the telescope has evolved gradually in size and complexity. They need to exclude as much as possible the rain clouds, light pollution, and atmospheric distortion.[2] Many of them were placed at mountain tops, far from cities.

Hubble is the first major optical telescope to be placed in space, not earth, which enables it to provide an unobstructed view of the universe.[3] Orbiting high above the earth and its atmosphere, Hubble takes pictures of the universe and send it back to earth using radio waves.[4] Scientists thus can use Hubble to observe the most distant stars, galaxies, and planets.

Graph 2 Hubble

Hubble was launched on April 24, 1990.[5] According to NASA, Hubble transmits about 150 gigabits of raw science data every week.

Things are not that smooth for Hubble’s launch. Its original proposed launch was in 1983. However, technical delay, budget problem, and Challenger disaster postponed the plan.[6] Even after the launch, there were still problems to be fixed. The main mirror had some ground errors which compromised its capabilities. The issue was solved in 1993 with a serving mission which adjusts the mirror to its intended quality.

Graph 3 The Hubble Space Telescope took this picture of the Tadpole Galaxy and its tail of large, bright blue star clusters.
  
There is no specific retirement date for Hubble’s retirement, although it has already outlived its original lifespan.[7] Its last mission was accomplished in 2009. According to some preliminary reports last year, Trump administration may team up with the Sierra Nevada to bring new life to an old telescope and assign it the sixth mission.[8] Hubble is not the only telescope that NASA placed in the universe. Another one, James Webb Space Telescope will be built in the universe and orbit the Sun to provide us with a different perspective to see the space.[9]



Reference
[1] https://www.atnf.csiro.au/outreach/education/senior/astrophysics/galileo.html
[2] [3]https://www.nasa.gov/mission_pages/hubble/story/index.html
[4] https://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-the-hubble-space-telecope-k4.html
[5] https://www.nasa.gov/mission_pages/hubble/story/index.html
[6] https://en.wikipedia.org/wiki/Hubble_Space_Telescope#Challenger_disaster,_delays,_and_eventual_launch
[7] https://www.extremetech.com/extreme/244420-hubble-get-another-repair-mission-coming-years
[8] http://astronomy.com/news/2017/02/potential-hubble-repair-mission

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