Image taken in 1986. Next perihelion predicted: July 2061
(source: space.com)
2.- Deep Impact Mission
Deep Impact was a NASA space probe launched on January 12, 2005. It was designed to study the interior composition of the comet Tempel, by releasing an impactor into the comet. On July 4, 2005, the impactor successfully collided with the comet's nucleus. The impact excavated debris from the interior of the nucleus, allowing photographs of the impact crater. The photographs showed the comet to be more dusty and less icy than had been expected. The impact generated a large and bright dust cloud, which unexpectedly obscured the view of the impact crater (source: http://goo.gl/ORqmou)
Principal Investigator: Prof. Michael A'Hearn (UMD)
Comet Tempel 1 taken by Deep Impact Probe:
Deep Impact Ejecta Plume:
3.- Comet Shoemaker Levy 9
4.- Prof. Meg Urry on: "A meteor and asteroid: 1 in 100 million odds"
I encourage you to read the following opinion column by Prof. Meg Urry (Yale):
Asteroid 2012 DA14 passed closest on February 15, 2013. As the image above shows, it passed much closer than the orbit of the moon - closer even that orbiting geosynchronous satellites (22,000 miles). Image Credit: NASA, Source: http://goo.gl/OpGNsq
Chance of an asteroid like DA14 to pass close to Earth: once every decade or two.
Meteor (~50 feet across) fell, on the same day, near Chelyabinsk, Russia.
Chance of impact of a meteorite like this: once every 100 years.
Therefore, the chance of both events happening on any one day are indeed very small: 1 in 3,650 days times 1 in 36,500 days, or about 1 in 100 million!!!
