Solar Storm

Sent from my iPad

Begin forwarded 


Raging Solar Storm 'Blinds' Venus Spacecraft
by Denise Chow, SPACE.com Staff Writer
08 March 2012 Time: 12:01 PM ET
updated at 11:20 p.m. EST.

Strong radiation from one of the most intense solar storms in the past five years has temporarily "blinded" a European spacecraft in orbit around Venus, and mission controllers are now racing to fix the problem.

The European Space Agency's Venus Express probe, which is located much closer to the sun than Earth, experienced high doses of radiation from the recent solar storm, and on Tuesday (March 6) at 8:40 p.m. EST (0140 GMT March 7), spacecraft operators reported that Venus Express' onboard startracker cameras had become blinded.

After being bombarded by solar radiation Tuesday, the cameras were unable to pick up any stars, said Octavio Camino, the Venus Express spacecraft operation manager at ESA's European Space Operations Center in Darmstadt, Germany.

"We were not able to detect any stars, so we decided to switch to the B unit, but we saw exactly the same thing," Camino told SPACE.com. "Both of them were blinded by heavy solar activity. Since then, we have not been able to get them back on track, so we are doing a lot of things in order to keep the spacecraft in a safe configuration." [Photos: Huge Solar Flare Eruptions of 2012]

The startracker cameras take pictures of the sky and use internal databases to recognize the stars. The Venus Express probe uses this information to measure its position and orientation in space.

"This information is calibrated with another tool, called gyroscopes, that tell the spacecraft what it's pointing at and what its angular rotation is," said Paolo Ferri, head of ESA's solar and planetary mission operations. "So the spacecraft uses the gyroscope information plus the calibrated information from startrackers to realize its current attitude."

These cameras are crucial on all spacecraft, but are particularly important for interplanetary probes, since they have to continuously point their solar arrays at the sun and their antennas at the ground, Ferri told SPACE.com.

Spacecraft operators have full control of Venus Express but are relying on just the onboard gyroscopes and manual corrections as they attempt to regain the startracker cameras.

"For a human being, the startrackers are the eyes and the gyroscopes are the ears," Ferri said. "When you close your eyes, you can go on for a while with your ears if you're walking, but sooner or later you have to open your eyes and see where you are because the ears are not accurate enough."

The sun has been active all week, but a strong solar storm erupted after the sun fired off two huge solar flares Tuesday. These flares unleashed a wave of solar plasma and energetic particles, called a coronal mass ejection, into space. Space weather scientists predicted that as these particles travel through space and bombard Earth's magnetic field, satellites and power grids on the ground could experience some disruptions.

Venus Express' blindness is not expected to be permanent, and as the sun's activity has waxed and waned, the spacecraft has experienced similar glitches in the past. Still, the cameras have been out of commission for nearly 40 hours now, which is an unusually long time, Ferri said.

"On this spacecraft, we've had between five and 10 cases where solar activity caused a drop of the startrackers," he explained. "In a case like this one, where it lasts so long, it's quite unusual. We had one time in the past where this lasted 32 hours, but this is quite a long duration, so it's sort of an exceptional case for us."

ESA officials anticipate that this issue could last several days, particularly because the sun shows no signs of quieting down.

"We have several days of margin if we need it, but of course we're concerned," Ferri said. "We don't like to be in this type of situation. Normally these spacecraft are very autonomous, but this forces us to do a lot of manual operations that we normally don't do."

Eventually, the spacecraft is expected to return to normal operations, but ESA officials will continue to closely monitor the situation and maintain control of the probe. In the meantime, mission controllers have suspended many functions aboard Venus Express until things return to normal.

"We're not assuming that this type of problem is permanent," Ferri said. "The sun normally goes through increases and decreases like this, and we need just a short period of quiet for us to recover to normal and for the startracker to reacquire the stars by itself. It's a lot of manual babysitting now, but we don't expect this to last forever."


Copyright © 2012 TechMediaNetwork.com All rights reserved.

===============================================================

Big Solar Storm Packs Small Punch, But Not Over Yet
by Denise Chow, SPACE.com Staff Writer
08 March 2012 Time: 04:15 PM ET

A powerful solar storm that slammed into Earth today (March 8) triggered weaker-than-expected disruptions, but may still have a few more tricks up its sleeve, scientists say.

"We're probably not going to see much more from this storm, but I don't know if we can say it's quite over yet," said C. Alex Young, a solar physicist at NASA's Goddard Space Flight Center in Greenbelt, Md. "It might pick up a little bit, but we're not completely certain yet. We still have a bit of time to see if anything else is going to happen."

Two huge X-class solar flares (the most powerful type of sun storm) erupted from the sun late Tuesday (March 6), hurling a wave of plasma and energetic particles toward Earth. This blast, called a coronal mass ejection, reached Earth at around 5:45 a.m. EST (1045 GMT) this morning, according to officials at the Space Weather Prediction Center, which is jointly managed by the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service.

Early forecasts showed that the oncoming CME could boost solar radiation in space and trigger geomagnetic storms on Earth, potentially disrupting satellites, power grids and other electronic infrastructure.

But so far, the effects of the solar tempest have been milder than scientists originally predicted, mostly due to the orientation of the CME and Earth's magnetic fields, Young told SPACE.com.

"The orientation of the magnetic field in the CME is a big determining factor for how strong or weak the event is going to be," Young said. "If it's oriented more southward, which is opposite to Earth, then we expect a stronger storm, but it appears that this one was very much north oriented." [Photos: Huge Solar Flare Eruptions of 2012]

Currently, only moderate effects have been felt, but the magnetic field of the CME is dynamic and has the potential to change.

"The coronal mass ejection has a cloud of particles, but also embedded in that is a magnetic field structure," said Rodney Viereck, director of NOAA's Space Weather Prediction Test. "As the CME passes over Earth, the magnetic field strength and direction in interplanetary space will change direction and change strength. If that magnetic field direction goes southward, there's good connectivity, and energy in the CME gets translated very efficiently through the magnetosphere to Earth and we get a big storm."

Right now, there are some signs that show the southward part of the magnetic field may be approaching, but it's still too soon to tell, Viereck added.

So far today, no major disturbances have been reported, but several space probes likely experienced high doses of radiation from the onslaught of charged particles. A European spacecraft in orbit around Venus, for example, was temporarily blinded by high radiation, officials at the European Space Agency confirmed today.

Official reports also showed that several commercial airlines, including Delta Air Lines, took caution by re-routing flights that would normally have taken aircraft near or over Earth's polar caps, Viereck said.

"Commercial airlines have diverted some flights away from the poles," he said. "For instance, New York to Beijing — those flights do get diverted because the communication to talk from the cockpit down to the ground can get disrupted by these sorts of events. So, in order to remain in good communication on the ground, they have to skirt around the high latitudes." [Anatomy of Sun Storms & Solar Flares]

These delays are expected to last as long as the level of energetic protons remains high, which could be for another 24 to 48 hours, Viereck said. But, other than flight delays, no other major impacts were recorded, he said.

The energetic particles from the CME are also expected to create amped up displays of auroras (also known as the northern and southern lights) for lucky skywatchers at high latitudes. The light shows, however, will have to compete with tonight's full moon.

"We actually had a geomagnetic storm yesterday from a CME a few days before," Young said. "We saw auroras last night, and yesterday they were as far down as Michigan. Since this geomagnetic storm is not as strong, maybe we'll see something in the northern U.S., but probably not much farther south. We'll certainly see auroras though, and at high latitudes, I'm sure it'll still be pretty spectacular."

And while it hasn't packed much of a punch so far, this ongoing solar storm is the largest one scientists have seen in more than five years. 

"The solar storm currently underway is the largest so far during this solar cycle that began about two years ago and is expected to peak 12-15 months from now,"W. Jeffrey Hughes, director of the Center for Integrated Space Weather Modeling at Boston University, said in a statement. "While this is not a major storm, we haven't experienced one this large since the storm that occurred in December 2006 at the tail end of the last cycle."

Space weather experts will continue to monitor the situation, as the effects of the CME are expected to last into tomorrow morning, and the situation could still escalate later today.

Furthermore, the sunspot region that spewed the troublesome flares remains potent, and solar physicists warn that this active region could have more in store.

"It still have a very high potential for producing an X-size flare, so at the moment, there's still a good chance that we're going to see more significant activity from it," Young said.

Editor's note: If you snap an amazing photo of the northern lights sparked by these sun storms and would like to share it for a possible story or image gallery, please contact SPACE.com managing editor Tariq Malik at tmalik@space.com.

Note: An earlier version of this story suggested that the solar storm caused NASA's twin Grail spacecraft, which are currently in orbit around the moon, to go into safe mode. This is not the case, and the story was corrected at 7:00 p.m. EST to reflect this fact.


Copyright © 2012 TechMediaNetwork.com All rights reserved.

===============================================================