This figure shows the composition of a large event which was measured by ACE-SWICS on May 3 and compares it to standard solar wind composition (labelled slow solar wind). The Fe and O charge state show that the CME plasma is composed of a very hot (about 2.5-3 million K) and a very cold (less than 0.3 million K) component.
Click on image for full size
Image courtesy of ACE-SWICS
ACE Satellite Probes Solar Event
News story originally written on June 8, 1998
During the last months increasing solar activity has resulted in a higher occurence rate of
Coronal Mass Ejections (CMEs) than usual. In fact, one such event was recorded by SOHO on June 2, 1998. Another
CME was recorded by the
ACE spacecraft on May 3, 1998. SOHO observed a dramatic ejection of solar gas on the southwest limb of the Sun. The
ACE satellite measurements have shown that the composition of these CMEs exhibits surprising patterns.
These explosion events, first discovered in the 1970's, originate at the Sun's visible surface, the photosphere, and travel upward through its atmosphere, and then into its super-hot corona before speeding out into space, sometimes towards Earth. Before this May 3rd CME hit the Earth, the CME material passed the ACE satellite. On this occasion, the SWICS (Solar Wind Ionic Charge Spectrometer) instrument did not measure one homogeneous mass of material as the CME passed ACE. Instead, it was found that the CME consisted of an extremely hot region, followed by a cooler region and then another hot region of solar material. Further analysis is being done, but this discovery could change what scientists know about CMEs and about how CMEs affect the Earth's environment.
The ACE spacecraft will continue to track the solar wind coming from the Sun while solar activity increases. The ACE satellite serves as a spaceweather station while in orbit. The location of ACE enables it to provide about one-hour advance warning of any major geomagnetic activity that can cause aurorae or power losses here on Earth.
As we near solar maximum, more and more CMEs are likely to occur.
You might also be interested in:
For a planet to be affected by a blob of material being ejected by the sun, the planet must be in the path of the blob, as shown in this picture. The Earth and its magnetosphere are shown in the bottom
...more
It was another exciting and frustrating year for the space science program. It seemed that every step forward led to one backwards. Either way, NASA led the way to a great century of discovery. Unfortunately,
...more
The Space Shuttle Discovery lifted off from Kennedy Space Center at 2:19 p.m. EST, October 29th. The sky was clear and the weather was great as Discovery took 8 1/2 minutes to reach orbit for the Unitied
...more
A moon was discovered orbiting the asteroid, Eugenia. This is only the second time in history that a satellite has been seen circling an asteroid. A special mirror allowed scientists to find the moon
...more
Will Russia ever put the service module for the International Space Station in space? NASA officials are demanding an answer from the Russian government. The necessary service module is currently waiting
...more
During a period of about two days in early May, 1998, the ACE spacecraft was immersed in plasma associated with a coronal mass ejection (CME). The SWICS instrument on ACE, which determines unambiguously
...more
J.S. Maini of the Canadian Forest Service has referred to forests as the "heart and lungs of the world." Forests reduce soil erosion, maintain water quality, contribute to atmospheric humidity and cloud
...more
