Impactos em Júpiter

Há 3 semanas atrás, o Jorge Fonte escreveu este post, sobre um flash em Júpiter detectado por um astrónomo amador.
E eu próprio falei de outro impacto em Junho deste ano, neste post.

Agora confirmou-se que foram mesmo impactos em Júpiter.
Dois asteróides ou cometas terão atingido o gigantesco planeta.
Júpiter está a ser bombardeado 🙂

Folha:
“Astrônomos amadores conseguiram uma grande façanha com seus pequenos telescópios, segundo a Nasa, que confirmou na última quinta-feira (9) que, pela primeira vez, telescópios terrestres capturaram o impacto de um objeto relativamente pequeno com um planeta gigante.
(…)
Os fanáticos por astronomia foram os primeiros a detectar dois objetos “relativamente pequenos”, segundo a Nasa, que se desintegraram ao entrar na atmosfera de Júpiter formando uma bola de fogo, usando telescópios caseiros que instalaram em suas próprias residências.
(…)
Os impactos aconteceram entre 3 de junho e 20 de agosto, segundo os cientistas da Nasa, que acompanharam as observações e confirmaram que foram corretas.
Os especialistas calcularam que o objeto observado em 3 de junho tinha entre 8 e 13 metros de diâmetro, comparável ao asteroide RF12, que passou perto da Terra na quarta-feira (8).
Anthony Wesley, da Austrália, foi quem o avistou primeiro. O astrônomo amador já descobriu em julho de 2009 uma mancha escura em Júpiter que os cientistas não tinham detectado até então.
O segundo objeto, detectado em agosto, foi descoberto primeiro pelo japonês Masayuki Tachikawa, e pouco mais tarde confirmado por Aoki Kazuo e Masayuki Ishimaru.”
Leiam mais, aqui.

NASA:
“Amateur astronomers working with professional astronomers have spotted two fireballs lighting up Jupiter’s atmosphere this summer, marking the first time Earth-based telescopes have captured relatively small objects burning up in the atmosphere of the giant planet. The two fireballs – which produced bright freckles on Jupiter that were visible through backyard telescopes – occurred on June 3, 2010, and August 20, 2010, respectively.
A new paper that includes both pros and amateurs, led by Ricardo Hueso of the Universidad del País Vasco, Bilbao, Spain, appears today in the Astrophysical Journal Letters. In the paper, astronomers estimate the object that caused the June 3 fireball was 8 to 13 meters (30 to 40 feet) in diameter. The object is comparable in size to the asteroid 2010 RF12 that flew by Earth on Wednesday, Sept. 8, and slightly larger than the asteroid 2008 TC3, which burned up above Sudan two years ago.
An impact of this kind on Earth would not be expected to cause damage on the ground. The energy released by the June 3 fireball as it collided with Jupiter’s atmosphere was five to 10 times less than the 1908 Tunguska event on Earth, which knocked over tens of millions of trees in a remote part of Russia. Analysis is continuing on the Aug. 20 fireball, but scientists said it was comparable to the June 3 object.
“Jupiter is a big gravitational vacuum cleaner”
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Although collisions of this size had never before been detected on Jupiter, some previous models predicted around one collision of this kind a year. Another predicted up to 100 such collisions. Scientists now believe the frequency must be closer to the high end of the scale.
“It is interesting to note that whereas Earth gets smacked by a 10-meter-sized object about every 10 years on average, it looks as though Jupiter gets hit with the same-sized object a few times each month,” said Don Yeomans, manager of the Near-Earth Object Program Office at JPL, who was not involved in the paper. “The Jupiter impact rate is still being refined and studies like this one help to do just that”.”

Space.com:
“Two fireballs from collisions with Jupiter in June and August provided a great show for the skywatchers who spotted them, packing a punch and suggesting the gas giant could be in for frequent punishment.
In both instances, amateur astronomers using backyard telescopes were the first to detect two small objects that burned up in Jupiter’s atmosphere. Since then, the skywatchers teamed up with professional astronomers to study the fireballs, which were likely caused by rogue asteroids or comets.”

Universe Today:
“Poor Jupiter just can’t seem to catch a break. Ever since 1994, when our largest planet was hit by Comet Shoemaker-Levy, detections of impacts on Jupiter have occurred with increasing regularity. Most recently, an impact was witnessed on August 20. On June 3rd of 2010, (coincidentally the same day pictures from Hubble were released from a 2009 impact) Jupiter was hit yet again. Shortly after the June 3rd impact, several other telescopes joined the observing.
A paper to appear in the October issue of The Astrophysical Journal Letters discusses the science that has been gained from these observations.
The June 3rd impact was novel in several respects. It was the first unexpected impact that was reported from two independent locations simultaneously.
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Clearly, amateur observations led to some fantastic science. Modest telescopes, “in the range 15–20 cm in diameter equipped with webcams and video recorders” can easily allow for excellent coverage of Jupiter and continued observation could help in determining the impact rate and lead to a better understanding of the population of such small bodies in the outer solar system.”

Space Ref:
“Amateur Astronomers Are First To Detect Objects Impacting Jupiter.
Amateur astronomers using backyard telescopes were the first to detect two small objects that burned up in Jupiter’s atmosphere on June 3 and Aug. 20.
The object that caused the June 3 fireball was estimated to be 30 to 40 feet in diameter – comparable in size to asteroid 2010 RF12 that flew by Earth on Sept. 8.
The June 3 fireball released five to 10 times less energy than the 1908 Tunguska meteoroid, which exploded 4-6 miles above Earth’s surface with a powerful burst that knocked down millions of trees in a remote part of Russia. Scientists continue to analyze the Aug. 20 fireball, but think it was comparable to the June 3 object.
Jupiter is a big gravitational vacuum cleaner.”