Asteroids in the Distance

Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing. Significant threats do exist for rocks near 100 meters in diameter, which strike the Earth roughly every 1000 years. An object this size could cause significant tsunamis were it to strike an ocean, potentially devastating even distant shores. A collision with a massive asteroid, over 1 km across, is more rare, occurring typically millions of years apart, but could have truly global consequences. Many asteroids remain undiscovered. In the featured image, one such asteroid — shown by the long blue streak — was found by chance in 1998 by the Hubble Space Telescope. A collision with a large asteroid would not affect Earth’s orbit so much as raise dust that would affect Earth’s climate. One likely result is a global extinction of many species of life, possibly dwarfing the ongoing extinction occurring now. via NASA

Wikipedia article of the day for January 31, 2021

Wikipedia article of the day is Zebra. Check it out: Summary: Zebras are African equines with black-and-white striped coats and share the genus Equus with horses and asses. Zebras inhabit eastern and southern Africa and can be found in savannahs, grasslands, woodlands, shrublands and mountainous areas. They are primarily grazers, but can subsist on lower-quality vegetation. They are preyed on mainly by lions, typically fleeing when threatened but they may bite and kick. Several theories have been proposed for the function of their stripes, with evidence suggesting they are a form of protection from biting flies. Of the three extant species, Grévy’s zebra is endangered, the mountain zebra is vulnerable and the plains zebra (examples pictured) is near-threatened; the quagga, a type of plains zebra, was driven to extinction in the 19th century. Zebras communicate with vocalisations, body postures and facial expressions. Plains and mountain zebras practice social grooming, which strengthens social bonds. Zebras have featured in art and stories in Africa and beyond.

new like on January 30, 2021 at 12:56PM