A green-hued comet that has been lurking in the night sky for months is expected to be the most visible to stargazers this week as it gradually passes Earth for the first time in about 50,000 years.
The cosmic visitor will swing by our planet at a distance of about 42.5 million kilometers.
Here is an explanation of comets in general and this one in particular.
Photo: Reuters
WHAT IS A COMET?
Nicknamed “dirty snowballs” by astronomers, comets are balls of ice, dust and rocks that typically hail from the ring of icy material called the Oort cloud at our solar system’s outer edge. One known comet actually originated outside the solar system — 2I/Borisov.
Comets are composed of a solid core of rock, ice and dust and are blanketed by a thin and gassy atmosphere of more ice and dust, called a coma. They melt as they approach the sun, releasing a stream of gas and dust blown from their surface by solar radiation and plasma and forming a cloudy and outward-facing tail.
Comets wander toward the inner solar system when various gravitational forces dislodge them from the Oort cloud, becoming more visible as they venture closer to the heat given off by the sun. Fewer than a dozen comets are discovered each year by observatories around the world.
This comet last passed Earth at a time when Neanderthals still inhabited Eurasia, our species was expanding its reach beyond Africa, big Ice Age mammals including mammoths and saber-toothed cats roamed the landscape and northern Africa was a wet, fertile and rainy place.
The comet can provide clues about the primordial solar system because it formed during the solar system’s early stages, according to California Institute of Technology physics professor Thomas Prince.
WHY IS THE COMET GREEN?
The green comet, whose formal name is C/2022 E3 (ZTF), was discovered on March 2 last year by astronomers using the Zwicky Transient Facility telescope at Caltech’s Palomar Observatory in San Diego. Its greenish, emerald hue reflects the comet’s chemical composition — it is the result of a clash between sunlight and carbon-based molecules in the comet’s coma.
NASA plans to observe the comet with its James Webb Space Telescope (JWST), which could provide clues about the solar system’s formation.
“We’re going to be looking for the fingerprints of given molecules that we can’t access from the ground,” said planetary scientist Stefanie Milam of NASA’s Goddard Space Flight Center in Maryland. “Because JWST’s so sensitive, we’re expecting new discoveries.”
HOW CAN I SEE THE GREEN COMET?
Using binoculars during a clear night, the comet can be seen in the northern sky. On Monday, it appeared between the Big Dipper and Polaris, the North Star. And today, it was positioned to appear near the constellation Camelopardalis, bordered by Ursa Major, the Big Dipper and the Little Dipper.
Finding a remote location to avoid light pollution in populated areas is key to catching a nice view of the comet as it journeys past our planet heading away from the sun and back toward the solar system’s outer reaches.
Last week, the huge news broke that the Chinese Nationalist Party (KMT) would not host an open primary for its presidential nominee, but instead pick a candidate through a committee process. KMT Chairman Eric Chu (朱立倫) sent forth a few polite meaningless words about party unity in making the announcement. There’s great commentary on this momentous move, so I will say only that for those of you who think the KMT will “never be that dumb,” I have three words for you: Hung Hsiu-chu (洪秀柱), the unelectable candidate the party chose for the 2016 presidential race. Criticism of the Democratic Progressive
Anyone who has been stung by a black-tailed tiger hornet (Vespa basalis) would understand my immediate trepidation at stumbling on them while hiking Kaohsiung’s Weiliao Mountain (尾寮山). I’ve been stung a few times by these flying hypodermic needles, and the shock of pain lives up to their “murder hornet” moniker. Should I try to navigate around them, or get the hell off the mountain? NO 47 OF THE SMALL 100 PEAKS Weiliao Mountain (1,427m) is No 49 of the xiaobaibue (小百岳, “small 100 peaks”). I’d come here late last year to achieve a two-pronged ascent of the peak, breaching the trail on
The opportunity that brought Ming Turner (陳明惠) back to Taiwan a decade ago had an environmental theme, but since then, she admits, paying attention to environmental issues “hasn’t really been my thing.” Turner, who attended graduate school in the UK, initially returned to curate an event in Kaohsiung’s Cijin District (旗津), not far from where she grew up. Some years after she and her husband decided they’d stay in Taiwan, they moved to Tainan’s Annan District (安南) with their two young children. Turner is now an associate professor in the Institute of Creative Industries Design and director of visual and performance
Among the many atrocities committed by the Japanese during World War II, the Sook Ching massacre was notable for the involvement of Taiwanese. Having captured Singapore in February 1942, the Japanese army and its accomplices killed at least 25,000 Chinese. Prominent among the invaders’ henchmen was Wee Twee Kim (Huang Duijin, 黃堆金), an interpreter-turned-enforcer who — as this riveting new book reveals — was one of many Taiwanese participants in abuses against overseas Chinese, Allied POWS and local civilians. As an employee of the Japanese Southern Asian Company, Wee had been posted to Singapore in 1917. He started out managing Chinese
RSS