Hubble examines Jupiter

The biggest planet in the solar system was hit by a comet or an asteroid on 3 June 2010. The Hubble telescope has examined the impact site.

 

The area where the luminous flash was noted on 3 June 2010 was examined by Hubble on 7 June. The lack of any mark in Jupiter’s bands of cloud shows that it was more than likely a small asteroid that was totally burnt up in the upper layers of the gaseous giant’s atmosphere. Credit: NASA, ESA, M. H. Wong (University of California, Berkeley, USA), H. B. Hammel (Space Science Institute, Boulder, Colorado, USA), A. A. Simon-Miller (Goddard Space Flight Center, Greenbelt, Maryland, USA) and the Jupiter Impact Science Team.

It was two amateur astronomers that noted the event: Anthony Wesley and Christopher Go (see this Enjoy Space New-in-Brief). They recorded a flash on their images which took place on Jupiter on 3 June at 20:31 UT (Universal Time). In July 2009, the same Anthony Wesley signalled a new black spot on the Jovian disc and Hubble examined it in detail. Analysis of the photographs taken by the space telescope made it possible to determine that it was a “scar” left by the impact of a 500 m wide asteroid.

Burnt up in the upper layers of the atmosphere
Obviously, the event noted by the two amateur astronomers on 3 June 2010 provoked the interest of the scientific community and on 7 June Hubble was once again put to work in order to take a close-up look of the area where the flash occurred. But the photographs from the space telescope do not show any spot or anomaly. Disappointing? Not necessarily, because now astronomers have data concerning 3 scenarios of very different collisions on the biggest planet in the solar system. First of all, the multiple impacts caused by the pieces of the comet Shoemaker-Levy 9 in 1995 (see photograph below).

In 1995, fragments from the comet Shoemaker-Levy 9 “bombarded” Jupiter and left several “scars” that Hubble studied in detail. Take a look at this picture and others in our portfolio entitled “Jupiter struck”. Credit: Hubble Space Telescope Team - ESA/NASA

The other two collisions are that of July 2009 mentioned at the beginning of the article and that of June 2010. The lack of any mark for the latter shows that the object — probably a small asteroid — was totally burnt up in the upper layers of Jupiter’s atmosphere and therefore never reached and disturbed the bands of cloud contrary to the two previous events. It is worth noting that the atmosphere of our Earth regularly protects us in the same way from small “wandering stones” that are entirely or almost entirely burnt up before reaching the ground.

In July 2009, another impact left an obvious scar in Jupiter’s atmosphere. Works recently published assess that an asteroid 500 m across was the cause. Credit: NASA, ESA, H. B. Hammel, MIT.

Jupiter loses one of its equatorial bands
The observation made using Hubble on 7 June 2010 also made it possible to study the disappearance of one of the gaseous giant’s equatorial bands. Even through an amateur telescope, it is easy to see the alternating light and dark bands that are so typical of this planet. In fact, the light bands are clouds of ammonia crystals which are covering up the dark coloured ones situated on a lower level in the Jovian atmosphere. The phenomenon is clear to see when Hubble’s recent photograph is compared to that taken in July 2009 (see below).

What a change in 11 months! The southern equatorial band (arrows) appears to have lost its colours... In fact, bands of ammonia crystal clouds are currently covering the darker clouds that are situated lower down in the Jovian atmosphere. These photographs were taken with Hubble’s new WFC3 camera that was installed during STS-125 mission (see this portfolio); this mission forms the basis of the IMAX Hubble 3D film on show at the Cité de l’Espace. Crédit : NASA, ESA, M. H. Wong (University of California, Berkeley, USA), H. B. Hammel (Space Science Institute, Boulder, Colorado, USA), A. A. Simon-Miller (Goddard Space Flight Center, Greenbelt, Maryland, USA) and the Jupiter Impact Science Team.

According to astronomers, these clouds of ammonia crystals should dissipate in the coming months and the equatorial band will return to its usual colours. A similar phenomenon occurred in the 1970’s. Hubble, and more powerful instruments on the ground compared to the 1970's will, however, make it possible to carry out a more detailed study of these changes.

Published on 17 June 2010