The movie below shows the PROBA2-SWAP view of the transit so far:
Venus appears to swing north and south in this movie – this was predicted by the operators of SWAP at the Royal Observatory of Belgium Solar Data Influences Center. It is caused by the orbit of the PROBA2 spacecraft around the Earth creating very different points of view of at different times in the orbit.
More movies to come!
Alongside of our coverage of the last Transit of Venus that most of us will get to see (the next one will be in 2117 for those of you who are particularly ambitious!) we are also launching a new online discussion forum: community.helioviewer.org.
Here, users can share interesting features and events they find and get help identifying solar phenomena. In addition to forums on topics such as “transits and eclipses” to “coronal mass ejections,” we also have other sections including “solar physics” and “heliophysics” for anyone interested in learning more about the science that goes on behind the pretty pictures and movies.
Check it out and let us know what you think!
Here are some of the many excellent videos made by Helioviewer.org users of the Transit of Venus seen by AIA…
EIT has been taking special images of the transit. From the vantage point of SOHO, Venus does not appear to cross the disk of the Sun. In the image below, the EIT image is in green.
Just to the north you can see the dark disk of Venus.
More to come with AIA, very soon!
We hope you have the opportunity today to view this event safely. Due to expected heavy traffic to NASA websites concerning today’s Transit of Venus, we are reproducing in full the safety advice given at NASA’s safe solar viewing site. We will carrying images as they become available to us, as will many other sites, including live streaming from Mauna Kea, Hawaii.
Safe Solar Viewing
The transit of Venus is a rare and striking phenomenon you won’t want to miss— but you must carefully follow safety procedures. Don’t let the requisite warnings scare you away from witnessing this singular spectacle! You can experience the transit of Venus safely, but it is vital that you protect your eyes at all times with the proper solar filters. No matter what recommended technique you use, do not stare continuously at the Sun. Take breaks and give your eyes a rest! Do not use sunglasses: they don’t offer your eyes sufficient protection.
Fantastic Viewing Resources
- Dr. Doug Duncan, astronomer, Department of Astrophysical & Planetary Sciences, Univ. of Colorado and Director of Fiske Planetarium
- Definitive advice on viewing the sun safely; by B. Ralph Chou, MSc, OD.
- Six ways to see the transit!; by Chuck Bueter
Viewing with Protection — Experts suggests that one widely available filter for safe solar viewing is number 14 welder’s glass. It is imperative that the welding hood houses a #14 or darker filter. Do not view through any welding glass if you do not know or cannot discern its shade number. Be advised that arc welders typically use glass with a shade much less than the necessary #14. A welding glass that permits you to see the landscape is not safe. Inexpensive Eclipse Shades have special safety filters that appear similar to sunglasses, but these filters permits safe viewing. Eclipse shades are available through retailers listed at http://www.mreclipse.com/Totality/TotalityApC.html under “Solar Filters.”
Telescopes with Solar Filters — The transit of Venus is best viewed directly when magnified, which demands a telescope with a solar filter. A filtered, magnified view will clearly show the planet Venus and sunspots (http://skyandtelescope.com/observing/objects/sun/article_101_1.asp). Never look through a telescope without a solar filter on the large end of the scope. And never use small solar filters that attach to the eyepiece (as found in some older, cheaper telescopes.) See “Solar Filters” as cited above for retailers.
Pinhole projectors — These are a safe, indirect viewing technique for observing an image of the Sun. While popular for viewing solar eclipses, pinhole projectors suffer from the same shortcomings as unmagnified views when Venus approaches the edges of the Sun. Small features like the halo around Venus will not likely be discernible. Pinhole projectors and other projection techniques are at http://solar-center.stanford.edu/observe/.
Related projection methods — One viewing technique is to project an image of the Sun onto a white surface with a projecting telescope. http://www.skyandtelescope.com/observing/objects/sun/Solar_Projection.html and http://www.astrosociety.org/education/publications/tnl/05/stars2.html. Others follow:
- The Exploratorium demonstrates how to view a planet in transit safely by projecting the image with binoculars. http://www.exploratorium.edu/transit/how.html.
- The Sunspotter telescope viewer (recommended for younger viewers) is commercially available from Learning Technologies Inc. at http://www.starlab.com.
Next week we get to see one of the rarest of solar system events, a transit of Venus across the disk of the Sun.
As seen from Earth, Venus will appear to cross the face of the Sun. The eye will see Venus as a tiny black dot moving across the Sun. Historically, the transit of Venus was used to measure the distance from the Earth to the Sun. Transits of Venus occur in pairs about 8 years apart, and each pair occurs about once every 100 years. The last transit was on June 4, 2004. The next one is June 5-6, 2012. The next one after that is in 2117!
Helioviewer.org will be providing near-real time images of the transit from AIA, SWAP and EIT. Please note that we expect a very high level of interest in this event and consequently a high level of demand on our resources.
The transit across the disk of Sun starts (first ingress) at June 5 22:09:38 UT and ends (last egress) at June 6 04:49:35 UT. However, Venus may be visible in AIA, EIT or SWAP maybe one or two hours earlier depending on the physical extent of the coronal emission over the limb of Sun.
Here’s what you need to know to enjoy this rare solar-system event.
(1) Will I be able to see it?
This map also shows where the transit is visible from. If you live somewhere where you can’t see the transit, or if the Sun is obscured, there are many places online where you can see it as it happens. Helioviewer.org will be providing near-real time images of the transit from AIA, SWAP and EIT.
(2) When is it happening?
Use the following link to find out when the transit will be visible at your location: http://transitofvenus.nl/wp/where-when/local-transit-times/
(3) How can I watch it safely?
The Sun is EXTREMELY BRIGHT and PRECAUTIONS MUST BE TAKEN to VIEW THE TRANSIT SAFELY. Without proper precautions, you can severely and permanently damage your eyesight. Please follow proper procedures as detailed here.
We hope to see some fabulous images and movies from this event. Good observing!
We are pleased to announce that images from the Sun Watching Active Pixel (SWAP) instrument on board the European Space Agency’s PRoject for On Board Autonomy (PROBA-2) spacecraft are now available through Helioviewer.org.
The Proba satellites are part of ESA’s In-orbit Technology Demonstration Programme, missions dedicated to the demonstration of innovative technologies. In-orbit demonstration is the last step on the technology development ladder. New technology products need to be demonstrated in orbit, particularly when users require evidence of flight heritage or when there is a high risk associated with use of the new technology. In-orbit demonstration is achieved through experiments on carriers of opportunity, such as the International Space Station, or through dedicated small satellites such as the Proba series, which was created to increase the availability of flight-testing opportunities.
PROBA-2 was launched on 2nd November 2009 from the Plesetsk Cosmodrome in northern Russia. SWAP started taking images of the Sun later in November 2009, and has been in operation ever since (we will be making these earlier images available as well as the most recent observations). SWAP demonstrates the space-based use of an image capture technology different from that used on AIA.
SWAP provides a wider field of view compared to AIA or EIT. It also is in a slightly different orbit than AIA, and so was able to observe the recent annular eclipse on May 20, 2012, whereas AIA did not see it. Check out this movie made by the SWAP team, or make your own at Helioviewer.org.
SWAP will also observe the upcoming transit of Venus, and due to the orbit of SWAP the predicted path will make for some interesting movies. AIA will also see the transit, but will see a different path.
For many more details on the science goals and operation of PROBA-2 and SWAP please visit the PROBA-2 Science Center. Thanks to the Royal Observatory of Belgium for providing these images to the Helioviewer Project, and we hope you enjoy them. Please let us know if you have any further questions.
Helioviewer.org and JHelioviewer will be unavailable on Tuesday, May 29 from approximately 14:00UT – 16:00UT for planned server maintenance. We apologize for any inconvenience this may cause.
We are currently experiencing some issues with our local network. Users of helioviewer.org may experience some difficulties in reaching the site, and users of JHelioviewer may experience difficulties in streaming data. The network problems are also making it difficult for us to acquire the most recent images; hence, SDO AIA and HMI images are currently lagging well behind near real-time.
Our network engineers are aware of these problems, and are working on them. We apologize for the interruptions to our services. We will be back to normal operations as soon as possible.
A new version of JHelioviewer is available for download. What’s new? This update release contains improved movie export functionality, an updated LASCO C2 coronagraph mask, the new SDO Cutout Service plug-in plus various bug fixes.
The new movie export menu makes it easier to set the exact scaling of the area you are interested in, and the processing itself is now performed on the graphics card using OpenGL:
The SDO Cutout Service plug-in allows you to request science-quality image data from the SDO/AIA and HMI instruments for the region of interest and time range selected in JHelioviewer:
A new version of Helioviewer.org has been released including better movie customization, support for embedding Helioviewer.org in remote sites, and a number of performance and bug fixes.
Support has been added for embedding Helioviewer.org into third-party websites, and JSONP support makes it easier for new versions of the front-end to be created which interact with the main Helioviewer.org back-end. Similarly, the front-end has been rewritten to allow for easier creation of custom front-end clients without having to re-implement a tiling system, etc.
The back-end movie queuing system has been ported from Ruby to PHP to allow for better integration with the rest of the back-end, and the movies table structure has been modified for improved time estimation and similarity searching. Additional options (frame-rate and movie length) are offered to allow users further control over the movies they create and the duration option has been moved to a more obvious location.
Let us know what you think, or if you have any suggestions. Feedback is always welcome.
Helioviewer.2.3.0 includes several new features to give users more control over how the site behaves. Let us know what you think, or if you have any suggestions. Feedback is always welcome.
* JSONP support
* Added option display date from last visit when returning to Helioviewer.org
* Added setting to automatically update images every 5 minutes
* Added support for embedding Helioviewer.org in other websites
* Added support for specifying frame-rate or duration during movie creation
* Added support for PROBA-2 SWAP data
* Created an installer diagnostic script
* Added support for tracking custom events in Google Analytics
* Movie and screenshot selection rectangle preserved during visit
* Data availability information included in getDateSources response
* Fixed bug #691356 JPX Summary file does not exist
* Fixed bug #783497 Port Helioqueuer to PHP
* Fixed bug #903360 Error occurs for certain layer orders when attempting to create AIA/LASCO
* Fixed bug #925542 The minimum width of the display window is too big
* Fixed bug #624857 After clicking “clear history” unfinished requests are still processed, and download links displayed
* Fixed bug #885795 Add image attribution to about dialog
* Fixed bug #888269 Attempt to normalize movie frame-rate instead of duration when possible
* Fixed bug #909795 Normalize date strings for API requests
* Fixed bug #909897 Mark movies that have not finished in less than x hours as Error
* Fixed bug #930628 Improve movie creation time estimation
* Fixed bug #942547 Validate value for dsun before attempting to process in front-side
* Fixed bug #609219 API should return an error message when an invalid parameter is specified in a request
* Fixed bug #783481 Report mouse coordinates immediately upon activation
* Fixed bug #787744 Add a checkSettings method to the UserSettings class to verify user settings integrity
* Fixed bug #876707 Included creation_time in FFmpeg metadata for mp4/webm movies
* Fixed bug #789515 Reduce filesize of WebM movies
* Flowplayer (3.2.7 => 3.2.8)
* jQuery (1.7.0 => 1.7.2)
* jQuery UI (1.8.16 => 1.8.18)
* jQuery.JSON (2.2 => 2.3)
* jQuery imgAreaSelect (0.9.5 => 0.9.8)
As you may have noticed, we are currently experiencing a lag in the availability of SDO images. The lag is happening upstream of Helioviewer. The Helioviewer Project provides images of scientific data. The science data is beamed down from the spacecraft , to a dedicated ground station (as outlined here) in New Mexico. The packets of data are first re-assembled to form the raw science data, and then have some corrections applied to yield data suitable for science applications. Data is constantly streaming off the spacecraft and being processed through this pipeline, which involves many different locations and institutions.
One of those science applications is visualization of the data. The Helioviewer Project takes that science data and converts those data to JPEG2000 images, which we then make available via www.helioviewer.org and www.jhelioviewer.org. We have to have the science data available to make the JPEG2000 images.
As soon as new SDO-AIA and HMI images become available, we will make them available to you. We regret the interruption to the stream of SDO data. Other data-sets are unaffected, and are available as usual.
Why does the orbit have this shape? It’s because SDO takes so many large images that it has to have its own ground station to receive all that data (around 1.5 TB/day). In order to keep the flow of data running off the spacecraft, its geosynchronous orbit was designed to maintain contact with the ground station. For more detail, please go to http://sdo.gsfc.nasa.gov/mission/project/specs.php.
What happened? Well, there was an eruption on the back side of the Sun, that caused a propagating disturbance in the solar atmosphere. that appears to have triggered a prominence lift-off on the front-side of the Sun. This is a great example of how the high cadence, continuous observations from Solar Dynamics Observatory give us a much better view of how distant parts of the Sun can physically influence each other. We liked this event so much we made and uploaded some movies of our own. The lower cadence of these movies allows you to see the swaying of coronal material in response to the disturbance from the initial eruption.
A colleague who works with LASCO data yesterday found this lovely spiralling eruption close to the south pole.
It’s a great example of how the magnetic field can influence the dynamics of erupting plasma. The eruption starts around 00:13 in the above video.