Clouds blocking the sun: a common sight. But that’s not all. To wit:
Averaging over the entire Earth, clouds block the Sun about 2/3rds of the time, although much less over many land locations. On the Sun’s upper right is a prominence of magnetically levitating hot gas. The prominence might seem small but it could easily envelop our Earth and persist for over a month. The featured image is a combination of two exposures, one optimising the cloud and prominence, and the other optimising the Sun‘s texture. Both were taken about an hour apart with the same camera and from the same location in Lynnwood, Washington, USA. The shaggy texture derives from the Sun’s chromosphere, an atmospheric layer that stands out in the specifically exposed colour. The uniformity of the texture shows the surface to be relatively calm, indicative of a Sun just past the solar minimum in its 11-year cycle. In the years ahead, the Sun will progress toward a more active epoch where sunspots, prominences, and ultimately auroras on Earth will be more common: solar maximum.
With last Sunday’s solstice came the northernmost sunset for 2020 and – as an added bonus for some – an annular solar eclipse. Some viewpoints were better than others. To wit:
At maximum eclipse, the New Moon in silhouette created a ring of fire visible along a narrow path at most 85 kilometers wide. The annular eclipse path began in central Africa, crossed south Asia and China, and ended over the Pacific Ocean. But a partial eclipse of the Sun was visible over a much broader region. In Hong Kong, this busy section of Jordan Street looks to the northwest, well-aligned with the track of the near solstice afternoon Sun. The street level view was composited with an eclipse sequence made with a safe solar filter on the camera. For that location the eclipse was partial. The Moon covered about 90 percent of the Sun’s diameter at maximum, seen near the middle of the eclipse sequence.
Behold: the very first images of the sun taken by the new Inouye Solar Telescope at the 3050m summit of Haleakalā in Hawaii. Three times more detailed than any previous image of the sun, each of the cells you see is around the size of Texas.
It’s hot work, ogling that fiery ball:
Focusing 13 kilowatts of solar power generates enormous amounts of heat — heat that must be contained or removed. A specialized cooling system provides crucial heat protection for the telescope and its optics. More than seven miles of piping distribute coolant throughout the observatory, partially chilled by ice created on site during the night.
Last month, ‘industrial designer and tinkerer’ Markus Kayser went out into the Sahara desert to field-test two devices he’d spent the last year developing: a solar powered laser cutter and the Solar Sinter (above), a 3D printer that makes glass objects whose only power source is the sun and whose only consumable is sand.