Ken Larsen's web site - Astronomy
I've had an interest in astronomy since my early childhood. Whereas other kids held Elvis and Buddy Holly as heroes, my heroes were Galileo and Copernicus. I received a telescope for a birthday present and used it see and show neighboring kids the craters of the moon, the moons of Jupiter, the rings of Saturn, and the phases of Venus. It was really cool.
In 2003 I bought a 5 inch reflecting telescope and used it to see more detail of my favorite stellar objects. I saw one of the poplar ice caps of Mars when Mars was at its closest approach in over 60,000 years on August 26, 2003. I also observed the planets Mercury and Uranus for the first time.
On January 3, 1986 I saw Halley's Comet. Unfortunately, it was just a blurry blob. [details]
On March 23, 1997 I saw Comet Hale-Bopp. It was spectacular as it had a nice tail.
On June 5, 2012 I saw a transit of Venus. The next one won't be until the year 2117.
On May 9, 2016 I saw a transit of Mercury. The next one will be November 11, 2019.
On August 21, 2017 I saw a total solar eclipse from South Carolina. [details]
The most notable element about astronomy is the vastness of the universe. In July of 2003 I read an article on the internet that estimated that there were 70,000 sextillion stars in the visible universe. That's 70,000 million million! That's approximately ten times the number of grains of sand in all of the earth's beaches and deserts! That's mind boggling!
Unfortunately, we likely will never be able to travel to any of the stars, or even communicate real time with aliens there. The nearest star, Proxima Centauri, is 4.22 light years away. That means it would require 4.22 years to reach that star if we were traveling at the speed of light (186,282 miles per second). Also, nothing can travel faster than the speed of light. This prohibits real time communication. A "hello" to the nearest star would require a minimum of 8.44 years to get a response. That's a depressing reality. It would be great to zip around the universe and see what life forms exist in various solar systems, but the distances prohibit that from ever happening. Too bad!
Accelerating up to the speed of light would take 355 days if done at gravitational acceleration (32 feet/second2). Any faster acceleration for a protracted length of time would cause damage to the human body. Ditto for deceleration down to a stopped position.
If one could travel at 10 miles/second, it would take over 78,611 years to reach the nearest star. [4.22 years X (186282 miles / 10 miles per second) = 4.22 X 18,628.2 = 78,611 years]
My favorite astronomy related web sites:
Planet viewing information. Identifies the best time during the year to view each of the planets in our solar system.
NASA's Solar System Exploration Site. Lots of pictures and information about the planets in our solar system.
NASA's Mars exploration site.
Pictures of Saturn and its moons from the Cassini-Huygens probe that is now orbiting Saturn.
The Messier Catalog. Messier objects are stellar objects (star clusters, nebulae, and galaxies) that reside outside our Milky Way galaxy. The most notable is M31, the Andromeda Galaxy.
How big is our solar system? Well, if you made a model of our solar system and depicted the earth as a golf ball (1.68 inches in diameter), the following chart would identify the size and position of the bodies in our solar system:
Distance from the sun
Alpha Centauri 85,630 miles
(over 1/3 of the way to the moon)
Useful tool: The following web site can be used to calculate alternative scale model dimensions for our solar system: http://www.exploratorium.edu/ronh/solar_system/
26 Pictures That Will Really Make You Re-Evaluate Your Entire Existence (shows how tiny and insignificant the earth really is)