Spacecraft discovers solar winds are weakening.

[chemisttree]

The Ulysses spacecraft , launched in 1990 and now in a polar orbit around the sun at a distance of roughly 240 million miles, is http://www.astronomy.com/asy/default.aspx?c=a&id=7424"!(?)

"The Sun's million mile-per-hour solar wind inflates a protective bubble, or heliosphere, around the solar system. It influences how things work here on Earth and even out at the boundary of our solar system where it meets the galaxy," says Dave McComas, Ulysses' solar wind instrument principal investigator and senior executive director at the Southwest Research Institute in San Antonio. "Ulysses data indicate the solar wind's global pressure is the lowest we have seen since the beginning of the space age."

How does he know that? I'm going to give him a call this afternoon...

"Galactic cosmic rays carry with them radiation from other parts of our galaxy," says Ed Smith, NASA's Ulysses project scientist at the Jet Propulsion Laboratory in Pasadena, California. "With the solar wind at an all-time low, there is an excellent chance the heliosphere will diminish in size and strength. If that occurs, more galactic cosmic rays will make it into the inner part of our solar system."

Anyone notice an increase in shot noise in their earth-based detectors? Will the increased cosmic rays induce more clouds to form and could that be responsible for the recent cooling off of the Earth's atmosphere?

 

[Waveform]

How does he know that?

I would think he is looking back at 'historical' data to draw any conclusions.
However, looking at the time lines gathering data from Ulysses any comments may be a bit premature.

I have been watching sunspot and choronal hole activity during this low end of the solar cycle. It also seems quite low. However , I do not have the expertise to make a connection between the two. Although I would not be entirely surprised if there was a commonality.

Will the increased cosmic rays induce more clouds to form and could that be responsible for the recent cooling off of the Earth's atmosphere?

Excellent question. My personal view is, could very well be.
Within the next several years this may take on much more credence.

 

[NatSusan]

I find this information about the Ulysses spacecraft and its observations of the solar wind and its effects on the heliosphere and Earth's atmosphere very intriguing. It's amazing that this spacecraft, launched almost 30 years ago, is still providing valuable data and insights into our solar system.

As for the question about how the scientists know that the solar wind's global pressure is the lowest since the beginning of the space age, I'm sure they have sophisticated instruments and methods for measuring and analyzing this data. But it would be interesting to hear more about their process and how they come to these conclusions.

I hadn't thought about the potential effects of increased cosmic rays on Earth's atmosphere and climate. It's definitely something to consider and further research. I'm curious to see if there have been any noticeable changes in shot noise in earth-based detectors and if there is a correlation with increased cosmic rays.

Overall, I think it's important to continue studying and monitoring the solar wind and its impact on our solar system. Who knows what other discoveries and insights the Ulysses spacecraft will reveal in the future.