Another Impact Flash on Jupiter

On August 20, 2010 a new optical flash has been observed on Jupiter. This is the third time in only 13 months that such events have been observed on the surface of this giant planet. Previous events occurred on July 19, 2009 and June 03, 2010. All these signs of impact have been recorded by amateur astronomers.

Masayuki Tachikawa, amateur astronomer from Japan, first reported his detection of the flash on August 20, 2010 at 18:22 UT with a Philips ToUcam Pro II attached to his 6-inch (150-mm) Takahashi TAO-150 f/7.3 refractor. Below you can see the detection image and the video showing the flash.

Credit: Masayuki Tachikawa

Credit: Masayuki Tachikawa

After the announcement by Tachikawa, another amateur astronomer from Japan, Aoki Kazuo, looking back at his Jupiter data taken independently, found what is the confirmation of the flash. In this case the two observers were separated by roughly 800 km, so Earth and its surrounding can be rule out as cause of the flash. These flashes are likely from meteors or small asteroid impact (~ less than 10 meters).

Credit: Aoki Kazuo

Like the event of June 03, this fireball did not produce any visible scar on the surface of Jupiter. (while the July 2009 event was detected just for the scar it left on Jupiter surface, due to a bigger impactor).

Thanks to their skill and new video cameras available on the market, amateur astronomers are now able to record short exposure videos necessary to detect these short-live events. It's now time to establish a worldwide network of telescopes to monitor Jupiter 24/7 to determine the current impact rate.

by Ernesto Guido

Recovery of comet P/2003 S2 (NEAT) = P/2010 P5

IAUC circular No. 9162, issued on August 17, 2010 announces our recovery of comet P/2003 S2 (NEAT) = P/2010 P5.

We found the comet on our first attempt to locate it on August 15, 2010. It was moving roughly 6 arc-minutes away from the nominal position at magnitude 19 (roughly 1 magnitude dimmer than predicted). We imaged it remotely, through the GRAS network, using a scope located in Mayhill (NM): 0.25-m, f/3.4 reflector + CCD.

We performed the second night of follow-up on August 17, 2010. Co-adding of 24 unfiltered exposures, 120 seconds each, showed the presence of a faint 15" tail in p.a. 356 deg.

Our recovery image of P/2003 S2 (NEAT)

According to the IAUC, the indicated correction to the prediction by B. G. Marsden on MPC62880 is Delta(T) = -0.33 day. The linked orbital elements by G. V. Williams and an ephemeris appear on MPEC 2010-Q08.

P/2003 S2 was last observed (before our recovery) on February 18, 2004.

By Ernesto Guido & Giovanni Sostero

Perseids 2010

The Perseid 2010 peak was expected on the night of August 12-13 between 18h and 07h UT with a ZHR (Zenithal Hourly Rate) of ~100 meteors per hour. (ZHR is a number that assumes a dark sky and the shower radiant at the zenith).

According to the first and preliminary results published on the IMO website, the observed ZHR maximum has been around 80-90 Perseids per hour in good agreement with the previsions of the dust stream models. The Perseid meteor shower is associated with the comet 109P/Swift-Tuttle. When the dust particles, spread out all along its orbit by this comet, strikes Earth's atmosphere, we see Perseids in the sky. The ZHR change accordingly to the Earth passing distance to the nearest comet dust trails and to its density. (the Perseid 2009 had a ZHR ~200)

Perseids 2010 - Activity Profile (courtesy IMO)

While the ZHR is decreasing, this meteor shower is not over yet and will last for the next few days.

Below you can find a meteor composite image (because the images were collected over several hours, the radiant of the shower is spread out) + animation. The images have been collected by our meteorcam located in Castellammare di Stabia (Italy) from 21h UT of August 12, 2010 to 03h UT of August 13, 2010. Most of this meteors are Perseids.

by Ernesto Guido

The Kamil Impact Crater in Egypt

An Italian-Egyptian team reported in July 22nd's edition of Sciencexpress, their detection in southern Egypt of an impact crater 45 meters in diameter and 16-meter-deep with a pristine rayed structure. Italian researcher V. De Michele, first found the crater in February 2009 during a Google Earth images survey. After that, an expedition was arranged to the area where this surprisingly "fresh" crater is located. In the area surrounding the crater the researchers found many tons of meteorites confirming the impact nature of this crater.

Newly discovered Kamil crater in Egypt

Largest recovered mass (ca. 80 kg!) at Kamil Crater

Including Kamil Crater, to date we know of only 176 impact craters on Earth's surface of which only 15 are less than 300 meters wide. This is due to erosion. The small craters lost their features and become unrecognizable. The Kamil crater is an exception because this is an extremely "fresh" impact crater and it escaped severe weathering (Italian-Egyptian researcher estimates the age at less than 5000 years). It is so well preserved that the radial streaks of ejecta thrown out during impact are still visible (usually these streaks are visible only on impact crater formed on body without an atmosphere and so with no weathering).

Due to its peculiarities this discovery is particularly important to better understand the impact science and to better assess the frequency of asteroid impacts on our Planet.

This is the official website of the Kamir Crater with more info and photos:

by Ernesto Guido

Remanzacco Observatory - Blog of Note

On July 20, 2010 our blog has been chosen by Blogger team as Blog of Note!!

We are happy for this award that arrive after 2 years and half (with 140 posts present at the moment, most with original material of our observations) from the creation of this blog devoted to Astronomy and in particular to Comets and Asteroids.

Thanks to Blogger and to everyone expressing their congratulations!!

Ernesto Guido

Rosetta flyby of asteroid (21) Lutetia

On July 10, 2010 ESA's Rosetta spacecraft imaged asteroid Lutetia within an estimated distance of 3170 kilometers. Lutetia (the largest asteroid yet visited by a spacecraft) was discovered in 1852 from the Paris balcony of French painter turned astronomer Hermann Goldschmidt. To honour his home city, he called it 'Lutetia', after the Roman name for Paris.

In 2008 Rosetta encountered the asteroid (2867) Steins at a distance of 802.6 km.

All images: CREDIT: (C) ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

Pre-flyby image! View of Lutetia at a distance of 80,000 km.

Lutetia imaged just before its closest approach with Rosetta

At a distance of 36 000 km, Rosetta took this image of Lutetia with the planet Saturn in the background.

Lutetia close approach by Rosetta - Animation (click for a bigger version)

Next Rosetta rendezvous, scheduled for 2014, is with comet 67P/Churyumov-Gerasimenko. This comet rendezvous is the ultimate goal of Rosetta in the attempt to try to solve some of the enigmas of our Solar System.

by Ernesto Guido

Impact Flash on Jupiter

Amateur astronomers Anthony Wesley (Australia) and Christopher Go (Philippines) have independently observed an impact flash on Jupiter. According to their images and videos, the impact flash happened at 20:31 UTC of June 3, 2010 and lasted only few seconds in Jupiter's faded south equatorial belt. The alert was first launched by Wesley and soon after confirmed by Go who happened to imaging the planet at the same time.

Credit: A. Wesley

Credit: Christopher Go

Wesley suggests that the impact "doesn't seem to have left any mark, so it probably burned up in the upper atmosphere before it reached the cloud deck. There were no visible remains at the impact point for the next half hour or so, until sunrise put an end to the imaging."

According to S&T website: "The flare occurred at longitude 248.8° in Jupiter's System I, 342.7° in System II, and 159.4° in System III. The latitude is 16° south. This region should be visible from about 4:00 to 6:30 June 4th UT, favoring observers in Europe and Africa when Jupiter is up before dawn. The impact site will return to good view about every 9 hours 56 minutes thereafter."

Major telescopes will be pointed on the area as soon as possible. So it's likely that we'll have more info available in the next few hours.

Link to Wesley webpage about this event (where you can download his 45MB video):

Link to download the video of this event by C. Go

Anthony Wesley was also the discoverer of the impact scar on Jupiter on July 2009.

For more info about the 2009 impact:

http://remanzacco.blogspot.com/2009/07/nasa-images-confirm-jupiter-impact.html

http://remanzacco.blogspot.com/2009/07/new-impact-on-jupiter.html

http://bit.ly/d6KuEM (Hubble Images of the scar)

http://bit.ly/cGOI1P (Published results on the Jupiter impact appeared in ApJ Letters)

UPDATE JUNE 16, 2010

Unlike previous impacts, Hubble imaging of the June 3rd impact site revealed no debris scar. The impact flash came from a giant meteor burning up high above Jupiter's cloud tops. The space visitor did not plunge deep enough into the atmosphere to explode and leave behind any telltale cloud of debris, as seen in previous Jupiter collisions.

Image Credit: NASA, ESA, M.H. Wong (University of California, Berkeley), H.B. Hammel (Space Science Institute, Boulder, Colo.), A.A. Simon-Miller (Goddard Space Flight Center), and the Jupiter Impact Science Team.

"We suspected for this 2010 impact there might be no big explosion driving a giant plume, and hence no resulting debris field to be imaged. There was just the meteor, and Hubble confirmed this," adds Hammel, a veteran Jupiter observer of the 1994 string of impacts.

by E. Guido & G. Sostero