Pictures of The Day #5
2009.06.23: Molecular Cloud Barnard 68
Credit: FORS Team, 8.2-meter VLT Antu, ESO
Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchus known as Barnard 68, pictured above. That no stars are visible in the center indicates that Barnard 68 is relatively nearby, with measurements placing it about 500 light-years away and half a light-year across. It is not known exactly how molecular clouds like Barnard 68 form, but it is known that these clouds are themselves likely places for new stars to form. In fact, Barnard 68 itself has recently been found likely to collapse and form a new star system. It is possible to look right through the cloud in infrared light.
2009.06.24: Noctilucent Clouds Over Germany
Credit & Copyright: Christoph Rollwagen
Sometimes it’s night on the ground but day in the air. As the Earth rotates to eclipse the Sun, sunset rises up from the ground. Therefore, at sunset on the ground, sunlight still shines on clouds above. Under usual circumstances, a pretty sunset might be visible, but unusual noctilucent clouds float so high up they can be seen well after dark. Pictured above last week, a network of noctilucent clouds cast an eerie white glow after dusk, beyond a local field near Potsdam, Germany. Although noctilucent clouds are thought to be composed of small ice-coated particles, much remains unknown about them. Satellites launched to help study these clouds include Sweden’s Odin and NASA’s AIM. Recent evidence indicates that at least some noctilucent clouds result from freezing water exhaust from Space Shuttles.
2009.06.25: Sarychev Peak Volcano in Stereo
Credit: Expedition 20 Crew, Crew Earth Observations Team, NASA
Stereo Image: Patrick Vantuyne
From 400 kilometers above planet Earth, the Expedition 20 Crew onboard the International Space Station (ISS) was able to witness a remarkable event from a remarkable vantage point — the June 12 eruption of the Sarychev Peak Volcano. The active volcano is located in Russia’s Kuril Island chain, stretching to the northeast of Japan. Emphasizing the orbital perspective, this stunning color stereo view was made by combining two images from the ISS and is intended to be viewed with red/blue glasses (red for the left eye). Punching upwards into the atmosphere at an early stage of the eruption, the volcanic plume features a brown column of ash topped with a smooth, bubble-like, white cloud that is likely water condensation. Below, a cloud of denser grey ash slides down the volcanic slope. About 1.5 kilometers of the island coastline is visible at ground level. The evolving ash plume posed no danger to the Expedition 20 crew, but commercial airline flights were diverted away from the region to minimize the danger of engine failures from ash intake.
Plant Family / Families: Fabaceae
Scientific Name and Author: Delonix regia Raf.
Name Location: Model Town Central Park, Lahore, Pakistan
Delonex regia, commonly known as royal poinciana or flamboyant tree, is a fast-growing (up to 1.5 metres per year), threatened native of Madagascar. Its epithets suggest something of the plant’s appeal to both the eye and the imagination. In early summer, the tree erupts into a spectacular conflagration of red, and a closer look reveals that each of the tightly clustered flowers has five gently crinkled petals, four of which are nearly uniform in shape, size and rich red hue, while the fifth (the ‘standard’), spotted and orange-yellow, rises elegantly to a few centimeters above its peers. Feathery, compound bipinnate leaves underlie the inflorescence. The trunk, which can sometimes reach 50 metres in height, bears smooth, light-brown bark. Due to the strength and complexity of its surface root system, the species is commonly considered invasive, and due to its popularity and abundance in the Caribbean, the tree is often thought to be a native of the region.
Though vulnerable in the wild, flamboyant tree is today naturalized in many tropical areas. It is hardy in zones 9 through 11 and cultivated in several different types of soil. Delonex regia is generally grown as an ornamental, though its seeds are sometimes used practically in percussive instruments like the maraca.
Plant Family / Families: Styracaceae
Scientific Name and Author: Styrax confusus Hemsley
Institution: UBC Botanical Garden
Accession Number: 028388-0565-1989
Name Location: Vancouver, British Columbia, Canada
Last month, a re-examination of the tree’s inflorescences—undertaken by botanist Beryl Zhuang as part of a garden-wide identification verification project—revealed that this original identification was in fact inaccurate, and that the species was rather—and rather appropriately in this case—Styrax confusus. The re-identification was supported by two distinct findings: firstly, close observation found the structure of the inflorescences to be racemose rather than paniculate (the latter of which is characteristic of dasyanthus); secondly, examination showed the plant’s fruit to be considerably larger than that of dasyanthus and less pointed at its apex (more obovoid). Though historically other species of Styrax (S. benzoin, for instance) have offered more raw materials to the sensuous curiosities of man (resins used in perfumes, incense, and medicines), confusus remains a lovely specimen, a fine addition to any garden, and, in this case, a subtle reminder of how the minute mysteries of plants can sometimes mislead even the trained eye of the scientist.
2009.06.25: Colocasia esculenta
Plant Family / Families: Araceae
Scientific Name and Author: Colocasia esculenta Schott
Institution: UBC Botanical Garden
Name Location: Vancouver, British Columbia, Canada
Colocasia esculenta is widely cultivated in the tropics and subtropics for its starchy edible corms and nutritious leaves. It is believed to be one of the earliest crops cultivated by humans. The origin of the species is uncertain, but it is presumed to be southeast Asia, the home of all other species in the genus. Evidence indicates cultivation in tropical India as early as 5000 BCE. From there its use spread westward to Egypt and the Mediterranean.
The comestible crop was also very important to Pacific Islanders. Cultivation in Hawaii led to the selection of over 150 varieties, including several used for the production of poi—a fermented paste of the cooked corms. Colocasia species contain toxic calcium oxalate crystals, which must be removed by soaking or cooking.
The large, peltate, heart-shaped leaves glow in the setting sun in today’s image. Leaves of C. esculenta can grow to 60 cm on plants that reach 1 to 2 m tall. Many variations of colour and form have been developed by a long history of cultivation, lending to the plants frequent ornamental use in modern day gardens. It is a returning perennial in zones 8b and 9, an evergreen perennial in its native tropical climate, and enjoys full sun or partial shade along with copious amounts of water. Here in Vancouver, the plant would not survive the cool winter, but each year it grows from its corms, which are lifted and stored in the fall.
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