Saturday, 12 January 2008

Voyager Plasma Science Experiment

Voyager Plasma Science Experiment

Solar wind data measured by VOYAGER 2 up through August 30, 2007

Edited and Add By:
Arip nurahman
Department of Physics, Faculty of Sciences and Mathematics
Indonesia University of Education
Follower Open Course Ware at MIT-Harvard University, Cambridge. USA.

As of 7 December 2007, Voyager 2 was 7.921 billion miles from Earth (84.293 Astronomical Units from the Sun), well beyond the orbit of Pluto. Voyager 2 is leaving the solar system at 36,000 miles per hour, which is 3.2 AU per year, or 1 light year per 18,600 years.

On the same date, the light travel time from Voyager 2 to Earth was 11 hours, 48 minutes, 41 seconds. Data are returned from the spacecraft at 160 bits per second, using a transmitter with about 25 watts (!) of power.

VOYAGER 2 data up through August 30, 2007
(Daily averages through November 25, 2007)

The outer atmosphere of the Sun expands outward to form the solar wind, with average speeds of 400 km/sec (roughly one million miles per hour). The Plasma Science Experiment on Voyager 2 measures that speed every 192 seconds, and that information is returned to Earth over the Deep Space Net, analyzed, and plotted here within a few days of receipt.

These plots show hourly averages of the solar wind speeds measured by Voyager 2 over the last 500 and 100 days, respectively.
Acquiring the Voyager 1 and 2 Data

Voyager plasma data are available from MIT through the links below or directly through anonymous ftp to (cd pub/plasma/vgr). Please look at the README files in each directory before using these data.

Voyager 1: hourly averages and fine resolution data are available by year for 1977-1980.
Voyager 2: hourly averages and fine resolution data are available by year for 1977-present. In addition, a file of daily averages for the entire Voyager 2 mission (de-spiked and then averaged by day) will be updated periodically.
Note that hourly average values for days 2007/240 (28 August 2007) to the present are being re-analyzed.
[go to voyager events page] Show recent events.

These plots show hourly averages of the solar wind dynamic pressure observed by Voyager 2 over the entire mission (100-day averages) and over the last four years (25-day averages), respectively. These pressures are normalized to 1 AU by multiplying by the square of the spacecraft's distance.

These plots show 50-day averages of the solar wind speed, density, and temperature over the life of the Voyager mission (from 1977 to the present), and 1-day averages over the last three years, respectively. The density shown is normalized to Earth by multiplying by the distance to Voyager in AU squared.