Friday, June 30, 2017
Star cluster Westerlund 1 is home to some of the largest and most massive stars known. It is headlined by the star Westerlund 1-26, a red supergiant star so big that if placed in the center of our Solar System, it would extend out past the orbit of Jupiter. Additionally, the young star cluster is home to 3 other red supergiants, 6 yellow hypergiant stars, 24 Wolf-Rayet stars, and several even-more unusual stars that continue to be studied.
Westerlund 1 is relatively close-by for a star cluster at a distance of 15,000 light years, givingastronomers a good laboratory to study the development of massive stars. The featured image of Westerlund 1 was taken by the Hubble Space Telescopetoward the southern constellation of the Altar (Ara). Although presently classified as a "super" open cluster, Westerlund 1 may evolve into a low massglobular cluster over the next billion years.
Image & info via APOD https://apod.nasa.gov/apod/astropix.html
Image Credit: ESA/Hubble & NASA
Lava deltas, similar to river deltas form wherever sufficient sub-aerial flows of lava enter standing bodies of water. The lava cools and breaks up as it encounters the water, with the resulting fragments filling in the adjacent seabed topography such that the flow can move further offshore sub-aerially. Lava deltas are generally associated with large-scale, effusive type basaltic volcanism.
Starting in January at Kīlauea Volcano’s Kamokuna ocean entry, the lava hit the salty water, shooting molten rock upward and outward, accompanied by a rising, steamy cloud of acid.
Normally cooling lava would stack up, creating a rocky shelf on which the lava settles called a lava delta. But this time, the flow continued to gush nearly 100 feet down, into the sea, for a whole month.
Ocean Entry Hazards - Important info:https://volcanoes.usgs.gov/observatories/hvo/hawaii_ocean_entry.html
Thursday, June 29, 2017
The saddleback caterpillar (Acharia stimulea) is the larva of a species of moth native to eastern North America. These caterpillars have a pair of fleshy “horns” at either end, and these, like much of the body, bear urticating hairs that secrete an irritating venom. Stings can be very painful and can cause swelling, nausea, and leave a rash that can last for days.
Photo via redddit
GOES-16's Geostationary Lightning Mapper (GLM) captured this electrifying imagery of the lightning associated with the recent severe weather over the Mississippi Valley and southern Plains this past weekend.
According to a variety of media reports, the storms caused the deaths of at least 13 people, produced widespread heavy rain resulting in flash floods, high winds that down trees and left thousands without power, a late-season blizzard in Kansas, and several tornadoes.
GLM observes total lightning, including in-cloud and cloud to ground lightning, and will continually observe lightning flashes day and night across the Western Hemisphere. Of particular note in this animation is the horizontal propagation of lightning flashes occurring behind the line of intense storms. Rapid increases of lightning are a signal that a storm is strengthening and could become more dangerous. GLM, in concert with other forecaster tools, will help provide more accurate and earlier warnings of developing severe storms and give communities more time to prepare for impending severe weather.