Astronomy Picture of the Day 3-09-03

NASA ^ | 3-09-03 | Robert Nemiroff and Jerry Bonnell

[petuniasevan]

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2003 March 9 Farewell Jupiter Credit: Cassini Imaging Team, Cassini Project, NASA

Explanation: Next stop: Saturn. The Cassini spacecraft, launched from Earth in 1997, has now swung past Jupiter and should arrive at Saturn in the year 2004. Pictured to the left is a parting shot from Cassini in January that would not have been possible from Earth: Jupiter showing a crescent phase. From the Earth and all points sunward of Jupiter, the gas giant will always appear more fully lit than a crescent. Recent analysis of Jupiter images taken from Cassini bolsters indications that clouds well up from below in the light colored zones, not the dark colored belts, as believed previously. After arriving at Saturn, Cassini will decelerate to orbit the ringed world and send a probe to its

[petuniasevan]

Jupiter is not only an incredible sight in visible light, it is radio noisy.

Radio emission from Jupiter was first discovered at decametric wavelengths by Franklin and Burke in 1955. Since that time, Jupiter has proven to have a wealth of complex radio emission mechanisms. Below 40 MHz, cyclotron-maser emission dominates, with much of this being associated with the rotational phase of the volcanic moon Io. Between 40 MHz and a few GHz, the radio emission is dominated by synchrotron emission from magnetically trapped, highly relativistic electrons, which populate the region within a few Jovian radii of the planet. At higher frequencies, the thermal emission from the planet itself dominates -- Jupiter is often used as a calibrator at high frequencies.

Jupiter is also bright at some infrared wavelengths (and dark at others). The bright spot is moon Io.

Jupiter in ultraviolet (Hubble image) in 1994 soon after the collisions with fragments of comet Shoemaker-Levy 9.

Chandra image of Jupiter in X-rays.

[petuniasevan]

[BradyLS]

Amazing images, petuniasevan! I'm always fascinated by the pics featuring impact with fragments from the Showmaker-Levy/9 comet. I sometimes wonder if the scientists detected any change in the appearance or composition of Jupiter's bands after the the strike. It seems like an impact on Earth from any of the fragments would have had a a cataclysmic effect that we'd still be reeling from.

[petuniasevan]

impact on Earth from any of the fragments would have had a a cataclysmic effect

The spectacular collision of comet fragment G: it struck Jupiter with an estimated energy equivalent to 6,000,000 megatons of TNT (about 600 times the estimated arsenal of the world). The fireball from fragment G rose about 2000 miles above the Jovian cloudtops and was observed by many observatories (mostly in infrared).

Fragment G was about 2 miles in diameter. Cataclysmic wouldn't begin to describe an impact of such an object with Earth. "Total obliteration" is the term you're looking for.

This is a reason why it's so handy having Jupiter out there in harm's way. Its huge gravity well pulls in many comets that otherwise could impact us.

Hubble images of the Fragment G impact site. Note the "sooty" area. It's larger than the diameter of Earth.

MSSSO Image of Fragment G Impact Zone

This image shows the bright fireball caused by the impact of fragment G with Jupiter. This view of the impact, seen 12 minutes after the actual collision, was taken in infrared light with a camera at the Mount Stromlo and Siding Springs Observatory in Australia. Due to Jupiter's tremendous size compared to the comet, astronomers did not expect the collisions to provide such dramatic effects as that seen in this image.

HST Image of Comet Fragment G Impact Plume

This series of images depicts the development of an explosive plume arising from the collision of fragment G. Scientists believe that the plume is not detached from Jupiter, as the pictures imply. Instead, only the portion of the plume that has risen into the sunlight is visible while the lower portion is hidden by Jupiter's shadow. The plume feature expands over the 18 minute period shown here and is visible in a variety of wavelengths across the spectrum.

[petuniasevan]

Here's links to a lot of SL9 impact images.

http://nssdc.gsfc.nasa.gov/planetary/sl9/html/hubble_images.html

http://nssdc.gsfc.nasa.gov/planetary/sl9/html/calar_images.html

http://nssdc.gsfc.nasa.gov/planetary/sl9/html/mssso_images.html

http://nssdc.gsfc.nasa.gov/planetary/sl9/html/irtf_images.html

[petuniasevan]

Changes in the atmospheric bands? For a while. See the link.

http://www.jpl.nasa.gov/sl9/image291.html

[Joan912]

That is so incredibly cool! I absolutely love seeing images of other planets! Thanks so much! :)

[firewalk]

Good morning, thanks for the ping

[xJones]

"This is a reason why it's so handy having Jupiter out there in harm's way. Its huge gravity well pulls in many comets that otherwise could impact us."

Let us all be thankful for Jupiter. Awesome photos and information about the SL9 impact. Fragment G left a larger-than-earth size scar? Ouch.

[RightWhale]

There's all the hydrogen we'll ever need to power our buggies to the mall and back.

[mikrofon]

Fascinating images, bye Jove!

[Joe Hadenuf]

Great images!

[BossyRoofer]

Great work, beautiful images, keep it up!
APOD my favorite site!

[MozartLover]

Very beautiful, thank you!