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Ring Around Supernova 1987A
John M. Blondin (North Carolina State University)
One of the most exciting astronomical events of the 20th century occurred in February 1987 when the first naked-eye supernova in centuries appeared in the Large Magellanic Cloud. In the past decade, three rings of glowing matter have developed around the explosion site. Astronomers have shown that the rings are made of material that surrounded the supernova's progenitor star. This visualization shows how that sort of cold, dark material can begin to glow when a supernova blast wave crashes into it.
Video: 462 kB, MPEG
Supernova shock
In the movie, you see a cross-section view of one possible glowing smoke ring.
Imagine the supernova blast wave traveling from left to right; the circle on the right hand side represents a doughnut
of cold gas being hit by the blast wave. The calculation shows that the blast wave plows into the ring like a blowtorch; much of the gas is blown away, while the rest is set aglow by the blast wave's powerful kinetic energy. The gas reaches temperatures in the millions of degrees, hot enough to glow in X-rays as well as ultraviolet, visible, and infrared light.
Charles Liu
Comet Impact with a Gaseous Planet: The Comet
Mordecai-Mark Mac Low (American Museum of Natural History) and Kevin Zahnle (NASA Ames Research Center)
Video: 1 MB, MPEG
Motivated by the Comet P/Shoemaker-Levy 9 impact with Jupiter in the summer of 1994, scientists began to calculate the effects of such an impact on the comet as well as the planet. Comet Shoemaker-Levy 9 entered the Jovian atmosphere at 60 kilometers/second (about 40 miles/second) causing the comet to transform into a plasma. The temperature of the comet rose to about 50,000 K (90,000° F). As the comet entered the atmosphere, turbulence from the shock wave stripped away any loose fragments sending them streaming back into the wake. As the temperature and pressure increased, the comet was crushed, flattened, and spread out into a trail of debris before being completely destroyed.
Simulation details
Using a complex computer code to calculate the structure and density of the gas, scientists were able to predict what would happen to the gas in the Jovian atmosphere during the collision. Because a comet is such a loose body, the calculations were performed assuming a fluid body for the impacting comet. As the comet enters the atmosphere, a shock wave forms in front of the comet. Traveling deeper and deeper, turbulence begins to take its toll, breaking up the comet. Eventually, it explodes sending material high up into the atmosphere. As this material falls back into the atmosphere, it produces the spots or scars
that were seen on Jupiter for months after the collision.
Brian Abbott
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Comet Impact with a Gaseous Planet: The Atmosphere
Kevin Zahnle (NASA Ames Research Center) and Mordecai-Mark Mac Low (American Museum of Natural History)
Video: 438 kB, MPEG
Motivated by the Comet P/Shoemaker-Levy 9 impact with Jupiter in the summer of 1994, scientists began to calculate the effects of such an impact on the comet as well as on Jupiter. Once the comet had traveled deep into the atmosphere, it was ultimately destroyed in a powerful explosion. This explosion sent a plume of material shooting hundreds, even thousands, of kilometers above the cloud tops. The material eventually fell back into the Jovian atmosphere where it produced the scars
or spots seen on Jupiter after the collision.
The simulation
Using a complex computer code to calculate the structure and density of the gas, scientists are able to predict what would happen to the gas in the Jovian atmosphere during the collision. In this movie, the comet explodes sending material ballooning out into the atmosphere. After exploding from the upper cloud deck, the material will soon fall back to the atmosphere and come to equilibrium with the surrounding gas in the atmosphere.
Brian Abbott
