Asteroids

I am back from the 45th annual Division of Planetary Sciences meeting in Denver, Colorado, where I presented my findings on the study of the triple asteroid system (87) Sylvia through a poster and in a press conference (video here). Located in the asteroid main-belt, we know that (87) Sylvia possesses two moons since our publication in Nature Journal in 2005. Our team  has combined observations from professional-class telescopes and from small telescopes used by amateur astronomers to reveal that this 270-km diameter main-belt asteroid has a complex interior, probably linked to the way the multiple system was formed. Artistic... read more ❯

Almost 12h after the event, it is time to gather my notes on the Russian meteor event (#RussianMeteor) and my thoughts on this impact and those which may come soon. What do we know? (I collected these pieces of information from numerous of my colleagues. Thanks) Today February 15 2013 a meteor exploded over the region of Chelyabinsk, Russia near the Southern Ural Mountains at 9:20:26 am LT (03:20:26 UTC). The explosion  occurred at an altitude of ~15-20 km  and the bolide impact speed was estimated to ~20 km/s with a... read more ❯

This exceptional result was brought to my attention late on Friday evening, but it clearly deserves a short post on this blog. Chang'E 2, a chinese mission dedicated to the exploration of the moon was recycled to explore the Near-Earth Asteroid (4179) Toutatis  and succeeded. Launched on  October 1, 2010 aboard a Long March 3C rocket, the probe was in lunar orbit until August 25, 2011. The spacecraft is equipped with several instruments, such as stereo camera, Laser altimeter, Gamma/X-ray Spectrometers and a Microwave Detector. To date, no... read more ❯

Third day of the 2012 AGU Fall Meeting tomorrow, Wednesday December 5, and I anticipate another busy day. Julie Castillo from Jet Propulsion Laboratory and myself organized a session on the internal structure and composition of small solar system bodies (SSSBs). This session will give us an opportunity to discuss recent results on the compositions and physical properties of asteroids and comets.  The discussion and results should be new since our view on the internal structure of SSSBs has changed drastically over the past decade thanks to the exploration with spacecrafts and the discovery of satellites around several asteroids. [caption id="attachment_1477"... read more ❯

Some news about the Jupiter flash which was detected on September 10. I reported the absence of detection in the visible light from data collected by amateur astronomers. Glenn Orton, a  colleague from the Jet Propulsion Laboratory,  sent me yesterday two observations of Jupiter taking with the IRTF telescope and the SpeX Guiding camera in the near-infrared. No scar, or debris field, can be seen at the location of the flash. The meteoroid did not enter in the inner part of the planet atmosphere. This observation confirms that it was most likely a meteor. [caption id="attachment_1417" align="alignnone" width="480" caption="2.3 um observations... read more ❯

As I mentioned in this blog, yesterday two amateur astronomers reported the detection of a flash on Jupiter yesterday on September 10. Since then, various teams have been working around the clock to estimate if this event was a meteor or a large fireball. The results are coming... Ricardo Hueso, a colleague from University of the Basque Country in... read more ❯

An amateur astronomer reported the visual detection of a fireball on Jupiter at 11:35 UT (September 10 2012) last night. It was confirmed on a video recorded from Texas. This is the 6th impact of Jupiter detected so far. Astronomer Dan Petersen saw today September 10 2012 at  11:35 UT a bright flash on Jupiter which lasted 1 or 2 seconds. It estimated its... read more ❯

There will be an oral session on Evolution and Exploration of Asteroids tomorrow from 8am to 10am, followed by a poster session from 1:40pm to 6pm, at the AGU Fall Conference, San Francisco, CA. Ben Weiss, Linda Elkins-Tanton (both from MIT) and myself are conveners of this session. It will be chaired by A. Mainzer (JPL) and myself. I am attaching the schedule of the session below. We will discuss the recent and future space missions dedicated to the Exploration of asteroids in the main-belt, the contribution of space-based and ground-based telescopes, and new ideas on the evolution of asteroids and... read more ❯

The official EPSC-DPS press-release about our latest discovery on the analysis of the moons of (93) Minerva and understanding of the composition of this main-belt triple system is finally out. Two years ago, I reported on this blog the discovery of those moons. Let's confess that I am glad to have finally solved secrets of this enigmatical main-belt asteroid. It was one of the most difficult multiple systems to characterize and understand due to its strangely spherical shape. Hopefully it will give birth to follow-up works... read more ❯

Last Tuesday July 19 at 3:25am PDT, several SETI REU students and colleagues from SETI institute and Observatoire de Paris were on the road. They were looking at the sky with  tiny telescopes and surrounding by complex instruments somewhere in the middle the Californian countryside to witness and record a rare event: the occultation of a bright 7-mag star by the double asteroid (90) Antiope. (90) Antiope is clearly a remarkable and unique binary asteroid. It is made of 2 large (~86 km) ellipsoidal components orbiting around their center of mass in 16.5 hours, describing a circular orbit with a... read more ❯