Daily Archives: 05/04/2010

Another chance to hear Brian Cox speak

On twitter Professor Brian Cox who presents the Wonders of the Solar System program has announced a speaking date in Manchester:

While you still remember me after #wonders – I’m giving public talk at University of Manchester evening of April 22nd. Details to follow

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Aurora alerts tripping all over the place

Just before lunchtime (BST) with the sun shining brightly, the shuttle vanishing high into the atmosphere and the clouds blocked all but the rain from the eyes down below here in Cumbria, something happened outside the magnetosphere, the region around the Earth where the terestrial magnetic field dominates over outside fields.

The solar wind suddenly started to ramp up its speed. Since then, we have been in the grip of a faster than usual solar wind stream. Why is this important? Because the effect of the solar wind altering its flow properties is that the magnetosphere of the Earth stretches and contracts and this releases the energy that powers the aurorae. This is the Dungey cycle.

Information from the ACE spacecraft (tweeted by Kav) showed a small rise in temperature and density of the solar wind petering out just before 1pm BST followed by a shift to southward interplanetary magnetic field (which is the type most likely to produce auroral activity) and a rise in solar wind velocity that peaked ninety minutes later at the highest we’ve seen for some time and only now is returning to normal. Aurora Alerts on twitter shows sudden rises in activity during both these events hitting a peak between 6.67-7 on the Kp index, indicating an aurora that (if timed right) would’ve been visible from down here in Kendal. But where did it come from?

Spaceweather.com mention that in the past 24 hours, the closest we’ve had to any flare activity was a B1 class x-ray flare (a slight cosmic hiccup that barely registers as noticeable). It does mention a large coronal hole (a region that isn’t producing many x-rays compared to the rest of the solar disc, but will be producing a stream of fast solar wind). They predicted its effects would hit tomorrow or the day after, but it looks like the fast solar wind has either arrived early or been preceded by an unseen small coronal mass ejection.

Either way, it looks like solar activity is heating up once more and we’ll be able to enjoy more frequent appearances of the Sun’s effect on the Earth at night.

The Space Shuttle Discovery Launches

The space shuttle Discovery launched from the Kennedy Space Center at 6:21 ET (11:21 BST) this morning. The shuttle is headed for the International Space Station and a thirteen day mission to swap over some ammonia tanks, bring back an external experiment and do some general maintenance. STS-131, as the mission is called, also puts the number of women in space at four for the first time ever. Parking of the shuttle at the ISS will commence in two days time. All the major events will be broadcast on NASA TV and then put on NASA’s Youtube channel (with tweets warning of impending events), such as has happened with the launch below:

Chances to see the International Space Station flying overhead can be got from Heavens Above, if the orbit is presently right for your location.