Impact on Jupiter

This image, acquired by the Hubble Space Telescope, on 23 July 2009, shows a large dark cloud in Jupiter’s atmosphere, believed to be the result of the collision of a small asteroid with Jupiter. The rare cloud was discovered on 19 July 2009. On 20 August 2010, Jupiter was struck anew by another small asteroid.

Credit: NASA, ESA, and H. Hammel (Space Science Institute, Boulder, Colo.), and the Jupiter Impact Team

On 20 August 2010, at 18:22 UT, Japanese amateur astronomer Masayuki Tachikawa of Kumamoto city, Japan, observed, through his telescope, a flash in the thick colorful cloud bands enveloping Jupiter (approximately 142,000 km across), the largest planet. The flash appears to be due to an explosion in Jupiter’s atmosphere, resulting from the collision of a small asteroid with the giant planet.

This is the third record of an impact on Jupiter within only 13 months. Earlier asteroid impacts in Jupiter were recorded on 19 July 2009 and 3 June 2010, respectively. Interestingly, the 20 August 2010 event was confirmed by another Japanese observer. It left no trace or debris in Jupiter’s atmosphere, indicating the colliding object was small. In the movies documenting the impact, the impacting object is visible as a point source of light, blinking on Jupiter. 

The July 2009 event, first spotted by Australian amateur astronomer Anthony Wesley, however, left a large dark cloud in Jupiter’s atmosphere, comparable in area to the Pacific Ocean. The cloud was later observed from space, by the sophisticated Hubble Space Telescope (HST). The colliding object is estimated to have been less than 1 km across. The June 2010 impact was detected independently by Wesley and amateur astronomer Christopher Go in the Philippines. This impact was of a smaller magnitude, leaving  no trace in Jupiter’s cloud layers. 

The fragments of Comet Shoemaker-Levy 9

This image shows the fragments of Comet Shoemaker-Levy 9, which broke up, in July 1992, when it approached very close to Jupiter, due to the giant planet’s strong gravity, measuring 2.5 times that of Earth. It was acquired by the Hubble Space Telescope, on 17 May 1994.

Credit: NASA, ESA, and H. Weaver and E. Smith (STScI)

Almost 16 years ago, in July 1994, mighty Jupiter, whose mass is 320 times that of Earth, endured a series of spectacular successive impacts of more than 20 fragments of shattered Comet Shoemaker-Levy 9 (S-L 9). Comet S-L 9 was destroyed by Jupiter’s gravity, in July 1992, when it ventured too close to the planet.

The train of fragments of S-L 9 was discovered in March 1993, by David Levy and Eugene and Caroline Shoemaker. Astronomers were able to compute the trajectory of the fragments, and predict their impacts. The impacts occurred between 16 and 22 July 1994. They released a tremendous amount of energy, far dwarfing in power all the nuclear arsenals on Earth. Large, dark clouds were visible in Jupiter, even through small telescopes, due to the impacts. The event was extensively photographed, and documented by spacecrafts, ground-based observatories and amateur astronomers, worldwide.

References

SpaceWeather.com Website
The Planetary Society
Wikipedia

Further Reading

Jupiter
http://www.nineplanets.org/jupiter.html

Mysterious Flash on Jupiter Left No Debris Cloud
http://hubblesite.org/newscenter/archive/releases/2010/20/

Hubble Images Suggest Rogue Asteroid Smacked Jupiter
http://hubblesite.org/newscenter/archive/releases/2010/16/

Hubble Captures Rare Jupiter Collision
http://hubblesite.org/newscenter/archive/releases/2009/23/

Aymen Mohamed Ibrahem
Senior Astronomy Specialist