June 23, 1999
Commemorating the 9th Anniversary of Hubble's Launch
Click on image for larger view.
Io and its shadow sweep across the giant face of Jupiter. Io, which is roughly the size of the Earth's moon, is the innermost of Jupiter's Galilean satellites. It orbits approximately 218,000 miles above the planet's surface once every 42.5 hours. The image was taken with the Wide Field and Planetary Camera 2 (WFPC2) of NASA's Hubble Space Telescope (HST).
Image Credits: John R. Spencer (Lowell Observatory) and NASA.
NASA released the above and other images of Io and Jupiter this past April in commemoration of the 9th anniversary of the launch of the Hubble Space Telescope (HST) on April 24, 1990.
During its nine years of observing the heavens, HST has logged 1.4 billion miles orbiting the Earth and gathered 6 terabytes* of data, equal to about 4 million floppy disks.
Hubble has observed roughly 12,000 celestial objects near and far, and snapped more than a quarter of a million exposures. The observations range from the Earth's moon and other bodies of the Sun's planetary system to stars in various stages of evolution, protoplanetary rings surrounding some of them, interstellar clouds, galaxies, galaxy clusters, and fuzzy-looking blue objects believed to represent the building blocks of today's galaxies and dating back to when the universe was a mere 5 to 10 percent of its present age.
We have regularly featured HST and its scientific exploits. Here are a few examples:
HST Monitors Martian Weather:
http://observe.ivv.nasa.gov/nasa/ootw/1997/ootw_970416/ob970416.html
A Star Is Born:
http://observe.ivv.nasa.gov/nasa/ootw/1995/ootw_951220/ob951220.html
HST Peers Deep into Star-Forming Region:
http://observe.ivv.nasa.gov/nasa/ootw/1997/ootw_970716/ob970716.html
The Most Energetic Gamma Ray Burst:
http://observe.ivv.nasa.gov/nasa/ootw/1998/ootw_981007/ob981007.html
Galaxies under Construction:
http://observe.ivv.nasa.gov/nasa/ootw/1998/ootw_980128/ob980128.html
Measuring the Expansion Rate of the Universe:
http://observe.ivv.nasa.gov/nasa/ootw/1999/ootw_990317/ob990317.html
The Second HST Servicing Mission:
http://observe.ivv.nasa.gov/nasa/ootw/1997/ootw_970205/ob970205.html
Additional HST images can be found by going to the Observation of the
Week Archive and our longer space science articles:
http://observe.ivv.nasa.gov/nasa/ootw/1999/oarch99_index.html
http://observe.ivv.nasa.gov/nasa/space/space_index.shtml
* The prefix tera is the International System of Units equivalent of "trillion" as used in American English (i.e., the number 1 followed by 12 zeros). The term is derived from the Greek teras, meaning "monster."
More Cool Stuff
- We obtained the above image of Io from press release 99-13 of the Space Telescope Science Institute:
- http://oposite.stsci.edu/pubinfo/pr/1999/13/index.html
As part of its Learning Technologies Project (LTP), NASA supports a number of educational Web sites that have excellent material on the space sciences: