This great video created from images taken by the Solar and Heliospheric Observatory (SOHO) on May 13 and 14 show Jupiter as it comes close to the Sun (from our vantage point) in a solar conjunction. But what it really looks like is the old “Space Invaders” video game, with Jupiter marching across the screen. There’s even a couple of sungrazing comets “pewpew-ing” in like the laser cannon shots in the game, and a coronal mass ejection completes the scene as an explosion (which is actually more like “Asteroids.”) For more fun, the team who created this video at the Naval Research Laboratory’s Sungrazing Comets website takes the time to show all the different objects in the scene, which amazingly includes Callisto and Ganymede, two of Jupiter’s moons. All it needs is the funky video game background music.
Continue reading “Watch Jupiter as a ‘Space Invader’”
How Big Are Sunspots?
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The short answer? Really big. The long answer? Really, really big.
The image above shows sunspot regions in comparison with the sizes of Earth and Jupiter, demonstrating the sheer enormity of these solar features.
Sunspots are regions where the Sun’s internal magnetic fields rise up through its surface layers, preventing convection from taking place and creating cooler, optically darker areas. They often occur in pairs or clusters, with individual spots corresponding to the opposite polar ends of magnetic lines.
(Read “What Are Sunspots?”)
The image on the left was acquired by NASA’s Solar Dynamics Observatory on May 11, 2012, showing Active Region 11476. The one on the right comes courtesy of the Carnegie Institution of Washington, and shows the largest sunspot ever captured on film, AR 14886. It was nearly the diameter of Jupiter — 88,846 miles (142,984 km)!
“The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well,” writes SDO project scientist Dean Pesnell on the SDO is GO blog. “As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.”
Sunspots are associated with solar flares and CMEs, which can send solar storms our way and negatively affect satellite operation and impact communications and sensitive electronics here on Earth. As we approach the peak of the current solar maximum cycle, it’s important to keep an eye — or a Solar Dynamics Observatory! — on the increasing activity of our home star.
(Image credit: NASA/SDO and the Carnegie Institution)
Venus Transit — There’s an App for That!
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There have been only six Venus transits since the invention of the telescope in the early 17th century. It was not until 1761 that the transit of Venus on June 6th was observed as part of the first ever international scientific observation project, instigated by Edmond Halley. Astronomers across the globe viewed the transit and the differences in their observations were used to triangulate the distance to Venus and, using Kepler’s laws, the distance to the Sun, the other planets and the size of the Solar System. Though the method used has not changed in the 251 years since, the equipment most certainly has.
For this transit, we have technology on our side.
In previous Venus Transits, expeditions were sent out far and wide and the 1761 transit was eventually recorded by 120 individual astronomers from 62 locations across Europe, America, Asia and Africa. They used only the simple telescopes of the day, fitted with dense filters, a pendulum clock to time the transit and quadrants to determine their exact latitude and local time. It is hardly surprising that their observations varied widely. Their calculations put the Sun’s distance between 130 and 158 million kilometres.
Transits happen in pairs. After 121 years a transit occurs followed 8 years later by another, then 105 years pass before the next pair and then the pattern repeats. Prior to the transit of 2004 the most recent transit was in 1882. There were none during the whole of the 20th century! We now approach the last chance to view a transit in our lifetime, the next will not occur until 2117.
Luckily, we’ve got some newly developed technology to help make this the most-observed transit ever!
Astronomers Without Borders are part of the Transit of Venus Project to get as many people around the world to observe the transit and to participate in a collective experiment to measure the Sun’s distance. To this end they have produced the Venus Transit phone app, available to download free for both iTunes and Android. Once downloaded you can start to practice timing the interior contacts of ingress and egress using a simulation of the transit. This is not as easy as it seems, as the black drop effect makes precise timing tricky so practice is definitely recommended. The app will tell you how far out you are so that you can perfect your timing and it will also predict times of contact based on your location together with times of sunrise and sunset.
On the day of the transit, the app will record the exact GPS time and your location, which is sent to the global database. Afterwards you can access your data on the website’s map to edit your entry, and upload descriptions, text, images, or movies and view other entries as well. This transit will be visible over most of the Earth except for parts of West Africa and most of South America, so download, get practicing and become part of a once in a lifetime, global citizen science experiment!
Find out more at Transit of Venus
Navy Scientists Spot New Solar Structures
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There’s something new under the Sun… well, just above the Sun, actually. Scientists at the Naval Research Laboratory have spotted structures in the Sun’s super-hot corona that may shed some light on the way its magnetic fields evolve — especially near the edges of vast, wind-spewing coronal holes.
Coronal holes are regions where the Sun’s magnetic field doesn’t loop back down but rather streams outward into space. Appearing dark in images captured in ultraviolet wavelengths, these holes in the corona allow solar material to flow directly out into the solar system, in many cases doubling the normal rate of the solar wind.
Recently witnessed by NRL researchers using NASA’s SDO and STEREO solar-observing spacecraft, features called coronal cells exist at the boundaries of coronal holes and may be closely associated with their formation and behavior.
The coronal cells are plumes of magnetic activity that stream upward from the Sun, occurring in clusters. Likened to “candles on a birthday cake”, the incredibly hot (1 million K) plumes extend outwards, punching though the lower corona.
Seen near the center of the Sun’s disk, the cells appear structurally similar to granules — short-lived areas of rising and falling solar material on the Sun’s photosphere — but seen from an angle via STEREO, the cells were witnessed to be much larger, elongated and extending higher into the Sun’s atmosphere. For comparison, granules are typically about 1,000 km in diameter while the coronal cells have been measured at 30,000 km across.
“We think the coronal cells look like flames shooting up, like candles on a birthday cake,” said Neil Sheeley, a solar scientist at the Naval Research Laboratory in Washington, D.C. “When you see them from the side, they look like flames. When you look at them straight down they look like cells. And we had a great way of checking this out, because we could look at them from the top and from the side at the same time using observations from SDO, STEREO-A, and STEREO-B.”
Watch a video below of cells made from images acquired by STEREO-B… note how their elongated structure becomes evident as the cells rotate closer to the Sun’s limb.
NRL researchers also noted that the coronal cells appeared when adjacent coronal holes closed and disappeared when the holes opened, suggesting that the holes and cells share the same magnetic structure. In addition, the coronal cells were seen to disappear when a solar filament would erupt nearby, being “extinguished” as the cooler strand of solar material moved across them. Once the filament passed, the cells reformed — again, indicating a direct magnetic association.
The coronal cells were also identified in earlier images from ESA and NASA’s SOHO and Japan’s Hinode spacecraft.
It’s hoped that further study of these candle-like structures will lead to more knowledge of our star’s complex magnetic field and the effects it has on space weather and geomagnetic activity experienced here on Earth.
Read the press release from the Naval Research Laboratory here, and on NASA’s STEREO site here.
Dark Figures Do An Eerie Dance On The Sun
NASA’s Solar Dynamics Observatory captured this video on March 27 – 28 of two large areas of “dark” plasma on the Sun’s limb, twisting and spiraling in our star’s complex magnetic field. The southern region bears an uncanny resemblance to three figures swaying to some spooky, unheard music… a real “danse macabre” on the Sun!
Continue reading “Dark Figures Do An Eerie Dance On The Sun”
What Does a Solar Storm Sound Like?
Of course, there is no sound in space, but sonfication is a process where any kind of non-auditory data is translated as sound. “We’re transforming space data into the sonic realm such that we can gain a new perspective, and begin to ask new questions,” said Robert Alexander, a doctoral student at the University of Michigan, getting his Ph.D in Design Science, who created this great sonification video of the recent solar storm activity. Alexander used data from two spacecraft: SOHO, studying the Sun, and the MESSENGER spacecraft at Mercury, which has the University of Michigan’s Fast Imaging Plasma Spectrometer (FIPS) on board, an imaging mass spectrometer.
Mercury was recently bombarded with a solar storm, and the sound created from particles colliding with the FIPS is utterly horrifying, sounding like the worst monster you could ever imagine.
Continue reading “What Does a Solar Storm Sound Like?”
Active Region Is Still Active!
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Even though the CME unleashed by active region 1429 initially hit Earth a bit softer than expected yesterday (read why here), it ended up gaining some extra “oomph” once the magnetic fields lined up right… enough to ignite some amazing displays of aurorae like the one shown above over Iceland, photographed by Jónína Óskarsdóttir!
And that wasn’t the last we’d hear from AR1429 either; at around 10:30 pm EST on March 8, the region lit up again with an M6.3 flare… although smaller than the previous X5.4-class flare, it produced a temporary radio blackout and released another Earth-directed CME, which is expected to arrive in the coming hours.
Dr. Alex Young, solar physicist at NASA’s Goddard Space Flight Center, reported this morning on his blog The Sun Today:
The flare produced a temporary radio blackout as well as a possible Earth directed CME. We will have to wait and see. The sunspot group still shows potential for more activity as the region sits near the central meridian of the Sun. Facing directly at Earth this is a prime location to produce more geo-effective solar activity.
Here is a look at the flare captured by the 131 Angstrom wavelength camera on the Solar Dynamics Observatory (SDO). This shows us the super hot 5-10 million degree plasma produced by the solar flare.
Dr. Young also noted that bright aurorae could be visible in lower latitudes as a result of the latest CME, expected to impact Earth at 1:50 am EST:
Aurora watchers at higher latitudes such as the northern US should keep their eyes out in the early morning and maybe even into tonight depending upon how this storm progresses.
Many times the size of Earth, active region 1429 has been the source of at least five significant flares over the past week. As it moves across the face of the Sun, its shape has become more and more complex — a sure sign, notes Dr. Young, that magnetic forces within it are twisting further and further towards a breaking point. And when they snap, there’s a flare.
“It’s interesting, they kind of look like a mole,” Dr. Young said during an interview on March 8. “And when you monitor a mole, they tell you as long as it stays in a nice symmetric shape and it doesn’t become really complicated and complex, it’s okay. It’s the same sort of thing with sunspots… when they become complicated and twisted, then that mean the magnetic fields inside of them have become more twisted, like a rubber band twisting around until little knots pop up in it. And right now we have been monitoring that sunspot and it is getting more complex.”
(See a photo of AR1429 taken from New Mexico!)
As far as the effects we see here on Earth are concerned, that’s all about the resulting CME — the enormous cloud of charged solar particles that gets blown out into the Solar System. If that cloud impacts Earth’s magnetic field, and if the direction of the cloud happens to be opposite the direction that Earth’s magnetic field is pointed, a lot of energy is “pumped into” our magnetosphere, resulting in a geomagnetic storm.
During yesterday’s CME impact the Earth’s magnetic field was pointed north — the same direction as the CME. As a result much of the solar material simply flowed along and over it. But the wake ended up getting caught up in the south-directed part of the field, ramping up the energy index (measured as Kp) as the hours progressed. As yet there’s no way to know for certain how a particular CME will align with Earth’s magnetic field.
According to physicist Dr. Philip Scherrer of Stanford University, “we still need better — or perhaps faster — models” to be able to accurately predict the orientation of incoming CMEs. “We are perhaps a few years of research away from completing the picture.”
Currently the geomagnetic storm level is at G3, which according to the NOAA’s Space Weather Scale could result in voltage problems on power systems, increased drag on satellites and “intermittent satellite navigation and low-frequency radio navigation problems… and aurora has been seen as low as Illinois and Oregon.”
So keep an eye out for northern lights in tonight’s skies, and stay tuned for more updates!
Thanks to Dr. Alex Young for the information! You can follow him on Facebook and Twitter and on his personal blog The Sun Today. Also thanks to Dr. Phil Scherrer at Stanford University and SpaceWeather.com for the heads-up on Jónína’s photo. See more of her aurora photography here. (Used with permission.)
Giant Sunspot Seen Through Dusty Skies
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The enormous sunspot region responsible for all the recent fuss and flares was easily visible from Earth yesterday… easily visible, that is, with the help of a natural filter provided by a New Mexico dust storm!
Photographer David Tremblay captured this image on March 7 through the dust-laden sky of Alto, New Mexico. Active Region 1429 can be seen on the upper right side of the Sun’s disk. Many times the size of Earth, this sunspot region has already erupted with several X-class solar flares and sent numerous CMEs our way — with potential for more to come!
“Blowing dust from the Tularosa Basin is so very dense that observing the sun was possible with the naked eye this evening,” noted David on SpaceWeather.com, where you can see more of his solar photos taken about the same time.
The image above was captured at 560mm with a Canon MKlll ESO1D.
View more of David’s photography here.
Image © David Tremblay. All rights reserved. Used with permission.
Sun Releases a Powerful X5 Flare
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Active Region 1429 unleashed an X5.4-class solar flare early this morning at 00:28 UT, as seen in this image by NASA’s Solar Dynamics Observatory (AIA 304). The eruption belched out a large coronal mass ejection (CME) into space but it’s not yet known exactly how it will impact Earth — it may just be a glancing blow.
Solar flares are categorized by a scale according to their x-ray brightness. X is the strongest class, followed by M and then C-class. Within each class the numbers 1 through 9 subdivide the flares’ intensity.
A run-in with an X5-class flare is a major geomagnetic event that can cause radio blackouts on Earth and disrupt satellite operations, as well as intensify auroral activity.
The GOES satellite data for the March 7 flare is below:
The CME is expected to impact Earth sometime on the 8th or 9th. Check back here or at Spaceweather.com for updates on the storm (and any subsequent aurora photos!)
Also, check out the video below, assembled by the SDO team. Just after the X5.4-class flare another smaller X1-class flare occurred, sending a visible wave cross the Sun.
Image courtesy NASA, SDO and the AIA science team. And thanks to Camilla Corona SDO for all the updates!
Sun Unleashes Powerful X-Class Solar Flare
The Sun has been quiet recently but early today (04:13 UTC on March 5, 2012) it unleashed a powerful X1-class solar flare and coronal mass ejection. The latest estimates indicate the CME will probably miss Earth, but hit Mercury and Venus. Even so, the science team from the Solar Dynamics Observatory says that high-latitude skywatchers should still be alert for auroras in the nights ahead. There was also an M2-class eruption from the same big and active sunspot, Active Region 1429, on March 4th which produced another, wider CME that might yet intersect Earth. The cloud is expected to deliver a glancing blow to our planet’s magnetic field on March 6th at 04:30 UT (+/- 7 hrs).
Check the latest forecast of the CME’s arrival from the NASA Goddard Space Weather Lab, which includes a great animation.
So, what’s the difference in the classes of solar flares and how could they affect us on Earth?
Continue reading “Sun Unleashes Powerful X-Class Solar Flare”