Europe Live In 1986 Time Has Come [UPD]
As a "periodic" comet, it returns to Earth's vicinity about every 75 years, making it possible for a person to see it twice in their lifetime. It was last here in 1986, and it is projected to return in 2061.
Europe Live In 1986 Time Has Come
Halley didn't live to see the comet's correctly-predicted return, but the comet was given his name. (For those looking for help with pronunciation, the name traditionally rhymes with the word valley.)
Scientists finally got an up-close look at the comet when it last visited in 1986 when several spacecraft were sent to Halley's vicinity to sample its composition. High-powered telescopes also observed the comet as it swung by Earth.
Years passed and the comet appeared in 1531, 1607 and 1682. Halley suggested the same comet could return to Earth in 1758. Halley did not live long enough to see its return (he died in 1742) but his work inspired others to name the comet after him.
The comet's pass in 1910 was particularly spectacular, as the comet flew by about 13.9 million miles (22.4 million kilometers) from Earth, which is about one-fifteenth the distance between Earth and the sun. On that occasion, Halley's Comet was captured on camera for the first time.
Several spacecraft successfully made the journey to the comet. This fleet of spaceships is sometimes dubbed the "Halley Armada." Two joint Soviet/French probes (Vega 1 and 2) flew nearby, with one of them capturing pictures of the nucleus, or "heart," of the comet for the first time.
The astronauts aboard Challenger's STS-51L mission were also scheduled to look at the comet. But, sadly, they never got the chance. The shuttle exploded about two minutes after launch on Jan. 28, 1986, due to a rocket malfunction, killing all seven astronauts on board.
When Halley's sweeps by Earth in 2061, the comet will be on the same side of the sun as Earth and will be much brighter than in 1986. At least one study has pointed out that it is difficult to predict Halley's orbit on a scale of more than 100 years, and that the comet could collide with another object (or be ejected from the solar system) in as little as 10,000 years, although not all scientists agree with the hypothesis.
In 1986, the European spacecraft Giotto became one of the first spacecraft ever to encounter and photograph the nucleus of a comet, passing and imaging Halley's nucleus as it receded from the Sun. Credit: Halley Multicolor Camera Team, Giotto Project, ESA More about this image
Halley is often called the most famous comet because it marked the first time astronomers understood comets could be repeat visitors to our night skies. Astronomers have now linked the comet's appearances to observations dating back more than 2,000 years.
In 1986, an international fleet spacecraft met the comet for an unprecedented study from a variety of vantage points. The science fleet included Japan's Suisei and Sakigake spacecraft, the Soviet Union's Vega 1 and Vega 2 (repurposed after a successful Venus mission), the international ISEE-3 (ICE) spacecraft, and the European Space Agency's Giotto. NASA's Pioneer 7 and Pioneer 12 also contributed to the bounty of science data collected.
The comet's closest approach to Earth occurred in 837, at a distance of 0.033 AU (3.07 million miles or 4.94 million kilometers). At that time, April 10, 837, Halley reached a total apparent brightness of about magnitude -3.5, nearly that of Venus at greatest brilliance. The light of Halley was spread over an extended area, however, so its surface brightness was less than that of Venus.
At aphelion in 1948, Halley was 35.25 AU (3.28 billion miles or 5.27 billion kilometers) from the Sun, well beyond the distance of Neptune. The comet was moving 0.91 kilometers per second (2,000 mph). At perihelion on Feb. 9, 1986, Halley was only 0.5871 AU (87.8 million km: 54.6 million miles) from the Sun, well inside the orbit of Venus. Halley was moving at 122,000 mph (54.55 kilometers per second).
Scientists calculate that an average periodic comet lives to complete about 1,000 trips around the Sun. Halley has been in its present orbit for at least 16,000 years, but it has shown no obvious signs of aging in its recorded appearances.
One may certainly visit the Chernobyl area, including even the exclusion zone, which is a 30 kilometre radius surrounding the plant, all of whose reactors are now closed. Although some of the radioactive isotopes released into the atmosphere still linger (such as Strontium-90 and Caesium-137), they are at tolerable exposure levels for limited periods of time. Some residents of the exclusion zone have returned to their homes at their own free will, and they live in areas with higher than normal environmental radiation levels. However, these levels are not fatal. Exposure to low but unusual levels of radiation over a period of time is less dangerous than exposure to a huge amount at once, and studies have been unable to link any direct increase in cancer risks to chronic low-level exposure.
Modifications have been made to overcome deficiencies in all the RBMK reactors still operating. In these, originally the nuclear chain reaction and power output could increase if cooling water were lost or turned to steam, in contrast to most Western designs. It was this effect which led to the uncontrolled power surge that led to the destruction of Chernobyl 4 (see Positive void coefficient section in the information page on RBMK Reactors). All of the RBMK reactors have now been modified by changes in the control rods, adding neutron absorbers and consequently increasing the fuel enrichment from 1.8 to 2.4% U-235, making them very much more stable at low power (see Post accident changes to the RBMK section in the information page on RBMK Reactors). Automatic shut-down mechanisms now operate faster, and other safety mechanisms have been improved. Automated inspection equipment has also been installed. A repetition of the 1986 Chernobyl accident is now virtually impossible, according to a German nuclear safety agency report7.
The map shows the expected years lived with disability across the world. In general, we tend to see that higher-income countries tend to spend more years with disability or disease burden than at lower incomes (around 10-11 years versus 7-9 years at lower incomes).
Given that life expectancy at birth is highly sensitive to the rate of death in the first few years of life, it is common to report life expectancy figures at different ages, both under the period and cohort approaches. For example, the UN estimates that the (period) global life expectancy at age 15 in 2005 was 73.6 years. This means that the group of 15-year-old children alive around the world in 2005 could expect to live another 63.6 years (i.e. until the age of 73.6), provided that mortality patterns observed in 2005 remained constant throughout their lifetime.
Age-specific mortality rates are usually estimated by counting (or projecting) the number of age-specific deaths in a time interval (e.g. the number of people aged 10-15 who died in the year 2005), and dividing by the total observed (or projected) population alive at a given point within that interval (e.g. the number of people aged 10-15 alive on 1 July 2015).
As an adolescent Taussig struggled with dyslexia, a disability that impairs reading comprehension. Dyslexia was not well understood at the time, and there were no treatments readily available. She grew close to her father, who supported her education and helped her succeed despite her reading disability. However, Taussig would struggle with reading and writing for years to come.
The human and economic displacements unleashed by Mexican modernization between 1876 and 1910 made this massive migration into the United States possible at a moment of intense labor demand in the United States. Mexican peasants had lost vast expanses of ancestral lands. High inflation in the price of basic commodities followed, producing profound income inequalities, which, when compounded by middle class grievances against the state, precipitated the Mexican Revolution of 1910. As different factions in this civil war wrestled for control of the state apparatus, perhaps as many as 1.4 million combatants and civilians died. Those able to move sought refuge from the violence in the United States. According to the Annual Reports of the Commissioner General of Immigration, between 1910 and 1929, about 661,000 Mexicans officially entered the United States as immigrants, a statistic that vastly underreports the true magnitude of this influx. Before 1924, federal statistics were kept only on foreign-born immigrants arriving at maritime ports, such as those in San Francisco, Los Angeles, Boston, New York, and Baltimore. During the most violent phase of the Mexican Revolution, from 1910 to 1914, on average, only 16,000 Mexican immigrants requested entry at all of these ports yearly. Clearly, most Mexicans were not traveling to the United States by ship; they were coming by train, on mules, or by foot. In 1924 alone, after inspection stations finally were constructed along the land border between Mexico and the United States, the number of Mexican entrants jumped to nearly 88,000, perhaps better reflecting the true dimensions of this exodus on a yearly basis.
The 2019 ozone hole has been very small and short-lived, which was mostly driven by unusual meteorological conditions. In particular, August and September 2019 showed exceptionally high temperatures at altitudes between 20 and 30 km above the Antarctic, stopping the formation of icy clouds that usually trap ozone-depleting molecules that, when released during springtime in the Southern Hemisphere, trigger ozone destruction. Taken together, the mitigation of ozone depletion is still very fragile and scientific evidence suggests that more action is still required to remove pressure on the ozone layer caused by ozone-depleting substances (ODS).
I would say this is the hardest day of our lives, worse even than the Chernobyl nuclear disaster of 1986. The difference is that at that time the lies of the Soviet regime were blatant, and when the truth was uncovered, millions of people dissented. Today we know the truth. Now we are not in the grip of an ideology with its constant falsehoods. The Maidan revolution brought down this empire inherited from the Soviet Union, but its monstrous corpse is still alive. 041b061a72