Tuesday, January 27, 2015
WAITING FOR DAWNCeres the largest object in the main Asteroid Belt is waiting for the arrival of Dawn as early as March 6th, 2015. This icy mass was originally called a planet when discovered in 1801 by an Italian astronomer named Giuseppe Piazzi. Since that time and with some debate its definition was changed in 2006 by the International Astronomical Union and Ceres is now classified as a dwarf planet.
If you are not familiar with Ceres, here are some interesting facts:
· It is fourteen times smaller than Pluto.
· It is 590 miles in diameter.
· It constitutes about 30% of the mass of everything in the asteroid belt.
· It completes a rotation every 9 hours and 4 minutes.
· It is believed to have a rocky core with an icy mantle.
· Its surface can warm to -36 degrees Fahrenheit.
· It has an atmosphere but it is very weak.
· It has a mysterious bright ‘white’ spot.
While the world awaits the first visit to Pluto this July by another mission, the space probe Dawn is nearing the end of its seven-year, 3.1 billion mile journey deep into the Asteroid Belt. I’m, wondering about the nature of this alien world. What does it look like? Will there be mountains, craters, and “cryovolcanoes” that spew frozen water miles into its thin atmosphere? What is that bright ‘white’ spot anyway? What lies below that frozen surface…a liquid ocean? Although the chance of life existing on Ceres is very low, scientists claim that if there is water there may be life. Nevertheless, it’s exciting to imagine a mysterious, strange-looking sea-monster world.
Dawn could change the shape and scope of future space missions. Dawn has already visited Vesta, the second largest object in the Asteroid Belt a few years ago and will enter the orbit of Ceres in early March. Travelling at 24,000 miles per hour is possible due to its twin ion thruster engines where xenon atoms are bombarded with electrons to form ions. The ions are charged and shoot out the engines up to 90,000 miles per hour. However, the thrust effect is minimal on the probe because of a zero-gravity, frictionless environment. Does this sound like science fiction to you? Perhaps you’ve already seen it in Star Wars, when Darth Vader’s TIE fighter would speed through the galaxy. Just like Darth Vader’s super-speedy vehicle, Dawn uses solar energy to feed electrons into its power-hungry engines. I believe this technology to be a stepping-stone to Mars.
More info at this link: “Where is Dawn Now”: http://dawn.jpl.nasa.gov/mission/live_shots.asp
My reference sources: www.earthsky.org, www.space.com, www.planetary.org, www.popsci.com, http://solarsystem.nasa.gov, http://news.discovery.com
To find out what Dawn discovered about Vesta you can see what Emily Lakdawalla, of the Planetary Society has to say in her Blog at http://www.planetary.org/blogs/emily-lakdawalla/2014/10091306-what-did-dawn-learn-at-vesta.html.