ESA's Cluster Spacecraft Makes Shocking Discovery

A recent observation by the ESA's Cluster Spacecraft was able to finally prove a 20-year-old theory. "On 24 January 2001, the four Cluster spacecraft were flying at an approximate altitude of 105 000 kilometres, in tetrahedron formation. Each spacecraft was separated from the others by a distance of about 600 kilometres. With such a distance between them, as they approached the bow shock, scientists expected that every spacecraft would record a similar signature of the passage through this region. Instead, the readings they got were highly contradictory. They showed large fluctuations in the magnetic and electric field surrounding each spacecraft. They also revealed marked variations in the number of solar wind protons that were reflected by the shock and streaming back to Sun."

Yeah, but not for 'tetrahedron.'

[Kadin2048]

No; however, I did have to look up bow shock [wikipedia.org], which frankly I think probably should have been linked in the summary.

Basically it's the 'wave' that precedes the sun or a planet as it passes through space, somewhat similar to the standing wave that you'd see in front of a big tanker ship going through the water. (Particularly one without a bulbous bow.) Rather than water, it's the solar wind that's being disrupted by the body's passage.

Neat diagram on Wikipedia, too.

"highly contradictory" indeed

[justthinkit]

"PhysOrg" means Physics, right? Well then, show me the numbers. And probably a graph or two. FFS, since when does "highly contradictory" pass for information?

Were the differences well within the error bars? I'm going with the latter until someone pastes a link with meat on its bones.

Re:Long-delayed echoes and magnetosphere shock wav

[crumley]

I think as much as anything this observation didn't happen before, because Cluster is the first mission to fly spacecraft in relatively tight formation in the correct location. Even with with Cluster, orbital dynamics are such that magnetopause and bow shock crossings do not happen that often, so there is not that much data on them.

As for shocking, I think that is just a bad joke. Though these are nice results, I don't think that anyone is that surprised by them.