A Space & astronomy forum. SpaceBanter.com

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Hubble
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

Saturn Seen From Far And Near



 
 
Thread Tools Display Modes
  #1  
Old May 27th 04, 04:12 PM
external usenet poster
 
Posts: n/a
Default Saturn Seen From Far And Near

MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLO
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Carolina Martinez/Nancy Lovato (818) 354-9382
Jet Propulsion Laboratory, Pasadena, Calif.

Cheryl S. Gundy (410) 338-4707
Space Telescope Science Institute, Baltimore, Md.

Image Advisory: 2004-131 May 26, 2004

Saturn Seen From Far And Near

As Saturn grows closer through the eyes of the Cassini spacecraft,
which is hurtling toward a rendezvous with the ringed world on June 30
(July 1, Universal Time), both Cassini and the Earth-orbiting Hubble
Space Telescope snapped spectacular pictures of the planet and its
magnificent rings.

Cassini is approaching Saturn at an oblique angle to the Sun and from
below the ecliptic plane. Cassini has a very different view of Saturn
than Hubble's Earth-centered view. For the first time, astronomers can
compare views of equal sharpness of Saturn from two very different
perspectives.

The view from Hubble, taken on March 22, 2004, is so sharp that many
individual Saturnian ringlets can be seen. When Cassini returned its
picture of Saturn on May 16, it was so close to the planet that the
imaging science subsystem narrow-angle camera could not fit the whole
planet in its field-of-view. Cassini is still about 20 million
kilometers (about 12.4 million miles) away and only 36 days from
reaching Saturn.

Hubble's exquisite optics, coupled with the high resolution of its
Advanced Camera for Surveys, allow it to take pictures of Saturn which
are nearly as sharp as Cassini's, even though Hubble is nearly a
billion miles farther from Saturn than Cassini. Cassini will
ultimately far exceed the resolution of Hubble during its close
encounter with Saturn. Cassini's sharpness began to surpass Hubble's
when it came to within 23 million kilometers (14 million miles) of
Saturn earlier this month.

Camera exposures in four filters (blue, blue-green, green and red)
were combined to form the Hubble image, to render colors similar to
what the eye would see through a telescope focused on Saturn. The
subtle pastel colors of ammonia-methane clouds trace a variety of
atmospheric dynamics. Saturn displays its familiar banded structure,
and haze and clouds of various altitudes. Like Jupiter, all bands are
parallel to Saturn's equator. Even the magnificent rings, at nearly
their maximum tilt toward Earth, show subtle hues, which indicate the
trace chemical differences in their icy composition.

Cassini has two cameras, a wide angle and narrow angle. This narrow
angle image was made using a combination of three filters (red, green,
blue) and was taken at a range of 24.3 million kilometers (15.1
million miles). The view is from 13 degrees below the equator.
Enceladus, one of Saturn's 31 known moons, appears near the south pole
at the bottom of the image.

The color differences between the Hubble and Cassini images are mainly
due to the different sets of filters used.

More than two decades have passed since a spacecraft last visited
Saturn -- NASA's Voyager-2 flew by Saturn in August 1981. Since 1990,
Hubble has produced high-resolution Saturn images, tracking storms and
auroral activity while providing crisp views of the rings over time
and from various angles.

Cassini will begin a four-year mission in orbit around Saturn when it
arrives on June 30, 2004 (July 1, 2004 Univeral Time). Six months
later it will release its piggybacked Huygens probe for descent
through Titan's thick atmosphere.

The Space Telescope Science Institute is operated by the Association
of Universities for Research in Astronomy, Inc., for NASA, under
contract with the Goddard Space Flight Center, Greenbelt, Md. The
Hubble Space Telescope is a project of international cooperation
between NASA and the European Space Agency. The Cassini-Huygens
mission is a cooperative mission of NASA, the European Space Agency
and the Italian Space Agency. The Jet Propulsion Laboratory, a
division of the California Institute of Technology in Pasadena,
manages the mission for NASA's Office of Space Science, Washington,
D.C. The Cassini orbiter and its two onboard cameras were designed,
developed and assembled at JPL.

Hubble images and additional information on Hubble are available at:
http://hubblesite.org/news/2004/18

Cassini images and information is available at:
http://saturn.jpl.nasa.gov

Hubble Photo Credit: NASA, ESA and Erich Karkoschka (University of
Arizona)

Cassini Photo Credit: NASA/JPL/Space Science Institute

-end-
Ads
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT +1. The time now is 11:15 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright 2004-2019 SpaceBanter.com.
The comments are property of their posters.