KA'U'S NIGHT SKIES FOR OCTOBER is written by Christopher Phillips, Astronomer and resident of Volcano. He is co-host of Stargazer on Hawai'i Public Radio:
This month the Hawaiian starline of Mānaiakalani becomes less prominent in our sky as we celebrate the arrival of Fall. It makes way for the starline of Kalupeokawelo, which will come to dominate our skies over the next couple of months. The starline of Kalupeokawelo, is known as The Kite of Kawelo, and it is composed of some asterisms (collections or patterns of stars) that may be familiar. The largest of these is the great square of Pegasus, which is the mythical winged horse of Greek mythology). This large formation of four bright stars is the body of the kite of Kawelo. The four stars of the Great Square are named for Hawaiian chiefs; Keawe of Hawaiʻi Island, Piʻilani of Maui, Kākuhihewa of Oʻahu, and Manokalanipo of Kauaʻi. From each corner star of the square we see celestial lines that are the guidelines of the kite. The lines are anchored in the northern sky to ʻIwakeliʻi, the constellation of Cassiopeia with its distinctive 'W' shape. There is also Kamōʻī, known as Cepheus the King in Greek mythology. In the southern sky they are held in place by Piʻikea, Diphda; Kaikilani, Ankaʻa; Kalanikauleleaiwi, which is the bright blue giant star Achernar;
Kūkaniloko, which is the star Fomalhaut; and Nālani, known as Alnair in Grus the Crane.
The story of the kite goes something like this. One day Kawelo watched his cousin Kauahoa releasing a kite into the sky. Kawelo, inspired by the kite riding on the winds, returned home and asked his grandparents for a kite of his own. They obliged and the next day he took to the skies with his kite, alongside his cousin Kauahoa.The two boys were competitive and both Kawelo's and Kauahoa's kites became entangled in the sky. During the fray the string holding Kauahoa's kite broke, and the kite came loose, landing somewhere in a distant forest. To this day, near Koloa, is a place called Kaho'oleināpe'a in reference to Kauahoa's fallen kite. Kawelo and Kauahoa could have come to blows over the loss of the kite, which was arguably Kawelo's fault, but Kauahoa attributed the loss of the kite to the elements and was not angry at Kawelo. However, this apparent battle of kites was a powerful sign to those onlookers who witnessed the dramatic display. It was a sign that Kawelo's mana, or supernatural power, was greater than Kauahoa's.
Fountains of Fire: When we look up into our island skies on a dark, clear night, we see the bright band of the Milky Way galaxy extending from horizon to horizon. This river of light is composed of hundreds of millions of stars, all of which are part of the great spiral galaxy that we call home. At the center of our galaxy is one, or possibly more, supermassive black holes. These are the gravitational engines that drive the galaxy and give rise to its graceful and spectacular shape. Out there in the Universe there are other galaxies, galaxies in which there are far more dramatic views to behold and Big Island astronomers at the Keck observatory, atop Maunakea, have been the first to witness such a sight.
Artwork and observation of black hole jets. Image from W.M. Keck Observatory
This spectacular sight is known as Porphyrion, named after a giant in Greek mythology. It is so distant that the light from it has traveled over 7.5 billion years to reach us, and as a result we are seeing it as it was around 7.5 billion years ago. So what is Porphyrion?Porphyrion is a pair of jets from supermassive black holes, these 'astrophysical jets' as they are known, are enormous, around 23 million light years across. That's 140 Milky way galaxies back to back, a vast fountain of fire of mind boggling size. The power of these jets is just as stunning as their size, with an equivalent power to that of trillions of suns. They erupt from the massive black holes and out into the cosmos. The galaxy from which the came cannot be seen, it is overwhelmed by the incredible power output from the dark engines within its core. These jets are so vast and energetic that it is thought that they are responsible for influencing the evolution of galaxies in the local Universe around them.
Image from NASA JPL/Caltech |
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FIRST LIGHT & FLIGHT FOR HVO'S NEW LIDAR SYSTEM is the title of this week's Volcano Watch, the weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates. This article is written by HVO geologist/GIS specialist Mike Zoeller:For over 15 years, lidar systems have been used intermittently at Kīlauea and Mauna Loa volcanoes. These have included aerial systems such as the one contracted by HVO for a survey of Kīlauea in 2019, as well as ground-based terrestrial systems like the one HVO borrowed from the U.S. Army Corps of Engineers' Cold Regions Research and Engineering Laboratory (CRREL) for surveys of Halemaʻumaʻu in 2021–2023.
Both system types require a GPS to record their position during the survey, but aerial systems also require a high-precision inertial measurement unit (IMU) to track directional roll, pitch, and yaw. These parameters are used for minute corrections of the instrument's position and orientation, allowing the measured features to correctly locate in the point cloud. Lidar systems are complex, and therefore expensive, so prior surveys on the Island of Hawaiʻi could only be conducted when permitted by the availability of funding and/or collaborators. That changed with Congress's passage of the Additional Supplemental Appropriations for Disaster Relief Act of 2019, which provided HVO with funds to purchase a lidar system among other upgrades in the aftermath of Kīlauea's 2018 eruption.
In April 2022 HVO used the funds to purchase a Riegl VUX-120 airborne lidar system, mountable to a helicopter and enabling surveys of more expansive areas than a terrestrial system. The instrument arrived at HVO in November 2022, but it was not yet operational. Actually, using the VUX-120 would require the building of a mount to attach it to HVO's contracted helicopter and integrating the system with a control computer along with other accessories.
The University of Hawaiʻi at Hilo's Spatial Data Analysis and Visualization (SDAV) Lab provided a template design for a helicopter mount, and for the integration, HVO again leaned on their collaborators at CRREL—who have operationalized various lidar systems of their own, including another VUX-120. The setup work was completed this past August.
In early September, a technician from CRREL visited HVO to teach local staff how to use the VUX-120 and to assist during its first operation. The system successfully completed a ground test at HVO's warehouse in Hawaiʻi Volcanoes National Park on September 2, followed by its first flight aboard the contracted helicopter on September 5. For the first flight, HVO decided to survey the vicinity of the June 3, 2024, Kīlauea Southwest Rift Zone eruption.
The test flight proved to be a resounding success; data were captured at a density of approximately 60 points per square meter (yard), enabling the construction of a high-accuracy digital elevation model (DEM) of the June 3 eruption vicinity. Some lessons were learned to further improve data quality in the future, which is especially important when the resulting DEMs may be used for critical assessments of volcanic hazards.
HVO continues to rely on photographic surveys for rapid-response mapping of topography during eruptions, but the VUX-120 will provide more definitive datasets when time allows for its slightly longer-duration surveys (not possible during the recent, brief Kīlauea East Rift Zone eruption). To our knowledge, this is the only helicopter-mounted lidar system operated by anyone in the USGS, so there may be opportunities to use it elsewhere in support of hazard assessments and scientific research.
HVO sincerely thanks the SDAV and CRREL teams for their support while we take our first steps into the world of airborne lidar, and we look forward to further collaboration in the future.
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Volcano Activity Updates
Kīlauea is not erupting. Its USGS Volcano Alert level is ADVISORY.
While the September 15–20 East Rift Zone eruption has ended, unrest continues at a low level in this region of Kīlauea. Over the past week, ending on Thursday, about 60 earthquakes were located in Kīlauea summit region, and about 50 were located in the upper-to-middle East Rift Zone. Ground deformation rates have greatly decreased since the eruption, but data show that magma is continuing to move at a low rate from the summit to the middle East Rift Zone. Future intrusive episodes and eruptions could occur with continued magma supply. The most recent measurement of sulfur dioxide (SO2) emission rate at the summit was 60 tonnes per day on September 17, 2024, and SO2 emissions were not detected at downwind of the eruption site on Monday, September 23.
Mauna Loa is not erupting. Its USGS Volcano Alert Level is at NORMAL.
No earthquakes were reported felt in the Hawaiian Islands during the past week.
HVO continues to closely monitor Kīlauea and Mauna Loa. Visit HVO's website for past Volcano Watch articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake information, and more. Email questions to askHVO@usgs.gov.
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