EXPLANATION by mifei

VIEWS: 17 PAGES: 7

									Video clips of European Space Agency

Scientific subject and topic: Astronomy and Astrophysics Title / year: Video clips of European Space Agency Movie producer: European Space Agency Websites of movie: Courtesy of the European Space Agency http://www.spacetelescope.org/videos Description of movie: Collection of astronomical and astrophysical video clips Link to Trailer Site: Courtesy of the European Space Agency http://www.spacetelescope.org/videos/html/heic0508f.html DVD: Spacetelesope.org
http://www.spacetelescope.org/hubbleshop/webshop/webshop.php?show=sales&se ction=cdroms

Title of scene: Video clips of European Space Agency: Deep Impact probe slams into comet Still:

Courtesy of European Space Agency Time interval: 00:00:00 – 00:00:18 Author: Heinz Oberhummer [ heinz@oberhummer.at ] Editor: Heinz Oberhummer [ heinz@oberhummer.at ] Scientific keywords: Comet, Asteroid, Impact Description of scene: Animation showing the collision between the 370 kilogram projectile released by the spacecraft Deep Impact and comet Tempel 1 on July 4, 2005. See also scene of Contact: Zooming through the Universe 1 See also scene of Video Clips of European Space Agency: Comet slams into Jupiter See also scene of Deep Impact: Comet produces Mega-Tsunami

Author: E-mail:

Heinz Oberhummer heinz@oberhummer.at

Movie: Video clips of European Space Agency Movie Scene: Deep Impact probe slams into comet Film Studio: European Space Agency

Basic level Comets are objects consisting of ice and dust and are therefore often called dirtysnowballs. When comets approach the Sun the surface is heated, the ice melts and boils and particles are thrown out . These particles are then blown away by the wind from the Sun, forming the characteristic tail of comets. Tempel 1 is a cigar-like object about 14 x 4 km in size. In the video, we see the impact of the 370 kilogram projectile (impactor) released by the mother spacecraft Deep Impact and the inner part comet Tempel 1 on July 4, 2005. The comet is named after it was discovered by Ernst Wilhelm Leberecht Tempel in 1859. The mission is named after the movie Deep Impact, a 1990 Hollywood blockbuster. The impact on the comet Tempel 1 was observed by the mother spacecraft, the Hubble Space telescope and observatories around the world. First results show that there is more dust than ice in the comet suggesting that comets are ‘icy dirtballs’, rather than ‘dirty snowballs’ as previously believed.

Comet Tempel 1 in observed in visible light and infrared light (artists rendition) [Source: The European Homepage for the NASA/ESA Hubble Space Telescope]

Author: E-mail:

Heinz Oberhummer heinz@oberhummer.at

4

Movie: Video clips of European Space Agency Movie Scene: Deep Impact probe slams into comet Film Studio: European Space Agency Advanced level Mission Deep Impact: Some of the scientific questions the mission Deep Impact was designed to answer were: • What are some basic properties of the comet: how is its surface formed, how dense is it, how strongly is it held together and how massive is it? • What is the composition of the comet? • Can the course of a comet be altered to reduce the effect of, or avoid, a collision with Earth?

Distant view of comet Tempel 1, the target of NASA's Deep Impact mission (artist's impression) [Source: The European Homepage for the NASA/ESA Hubble Space Telescope]

The asteroid Apophis: On the evening of April 13, 2029 the asteroid Apophis having a size of 320 km will pass the Earth in a distance of only 36650 km. This is about the height of our geostationary satellites and about 10 times closer than our moon. It will then be visible with the naked eye over Europe. However, then on April 13, 2036 Apophis will pass the Earth in a height of only 3,400 km (about half the Earth radius). According to the present calculation the chance of hitting the Earth is about 1:38000. This would correspond to an explosive force of about 100 million tons of TNT. If Apophis would crash into the ocean with a speed of about 50000 km/h it would create a 2500 m deep crater in the ocean thereby creating up to 20 m high tsunamis. The tsunami in 2004 in Asia was only half as high. However, global sustained effects are not anticipated. The Egyptian god Apophis is named after the Egyptian god of evil, destruction and darkness. The co-discoverer of the asteroid Apophis is a fan of the TV-series Stargate SG-1. It is probable that he named the asteroid after the character Apophis in this series being played by the actor Peter Williams (see website about character Apophis in Stargate SG-1 below).
3

The Egyptian god Apophis is named after the Egyptian god of evil, destruction and darkness. The serpent-like God Apophis is attacked with a butcher’s knife by his antagonist Re, the Egyptian sun God shown as a cat. [Source: Ottar Vendel, Ibisportal]

5

Redirecting Apophis: NASA is now making plans to land a transponder on the asteroid Apophis. A transponder is a tracking system similar to the ones used in commercial aircraft. This transponder could then determine the exact trajectory of Apophis. Once the trajectory was known the asteroid could be hit and redirected using a space ship with a mass of about 4 tons to reduce the risk of impact with the earth in 2036. In principle, this is possible and was demonstrated on a smaller scale with the mission Deep Impact.

Author: E-mail:

Heinz Oberhummer heinz@oberhummer.at

6

Movie: Video clips of European Space Agency Movie Scene: Deep Impact probe slams into comet Film Studio: European Space Agency

Scientific level Websites about the mission Deep Impact: NASA-site about the science and technology, results, gallery and news: http://deepimpact.jpl.nasa.gov/home/index.html Scientific background information: http://en.wikipedia.org/wiki/Deep_Impact_%28space_mission%29 Websites about Apophis: Countdown calendar of Apophis till possible impact with Earth: http://www.widgetgallery.com/?search=apophis&x=0&y=0 NASA-site about Earth Risk Impact Summary of Apophis: http://neo.jpl.nasa.gov/risk/a99942.html Website about character Apophis in Stargate SG-1: http://en.wikipedia.org/wiki/Apophis_%28Stargate%29 Website about the Egyptian god Apophis: http://www.nemo.nu/ibisportal/0egyptintro/1egypt/index.htm Websites about asteroids: NASA-site about asteroids and comets: http://nssdc.gsfc.nasa.gov/planetary/planets/asteroidpage.html Scientific description of asteroids: http://en.wikipedia.org/wiki/Asteroid Introduction to comets including images: http://www.solarviews.com/eng/asteroid.htm Educational site about comets: http://www.windows.ucar.edu/tour/link=/asteroids/asteroids.html Video clips about asteroid: http://www.spacetelescope.org/bin/videos.pl?searchtype=freesearch&string=Asteroid Websites about impacts of comets or asteroids: Scientific description of an impact event: http://en.wikipedia.org/wiki/Impact_event Calculator about the environmental consequences of impacts on Earth: http://www.lpl.arizona.edu/impacteffects/

7 Calculator about the effects of impacts on different planets: http://janus.astro.umd.edu/astro/impact/

Websites about movie Deep Impact: Background information: http://www.imdb.com/title/tt0120647/ Scientific background: http://en.wikipedia.org/wiki/Stargate_SG-1#


								
To top