Winter Solstice

In astronomy, the solstice is either of the two times a year when the Sun is at its greatest distance from the celestial equator, the great circle on the celestial sphere that is on the same plane as the earth's equator. In the Northern Hemisphere, the winter solstice occurs either December 21 or 22, when the sun shines directly over the tropic of Capricorn; the summer solstice occurs either June 20 or 21, when the sun shines directly over the tropic of Cancer. In the Southern Hemisphere, the winter and summer solstices are reversed.

Reason for the Seasons

The reason for the different seasons at opposite times of the year in the two hemispheres is that while the earth rotates about the sun, it also spins on its axis, which is tilted some 23.5 degrees towards the plane of its rotation. Because of this tilt, the Northern Hemisphere receives less direct sunlight (creating winter) while the Southern Hemisphere receives more direct sunlight (creating summer). As the Earth continues its orbit the hemisphere that is angled closest to the sun changes and the seasons are reversed.

Longest Night of the Year

The winter solstice marks the shortest day and the longest night of the year. The sun appears at its lowest point in the sky, and its noontime elevation appears to be the same for several days before and after the solstice. Hence the origin of the word solstice, which comes from Latin solstitium, from sol, "sun" and -stitium, "a stoppage." Following the winter solstice, the days begin to grow longer and the nights shorter.

Numbers announced for $636 million Mega Millions jackpot

This holiday season just got a lot merrier for at least two insanely lucky people.Two tickets matched the winning numbers in Tuesday night's $636 million Mega Millions jackpot -- splitting the second-largest prize in U.S. history.

One winning ticket was sold in Atlanta, and the other was sold in San Jose, California, lottery officials said.

The winning numbers were 8, 14, 17, 20 and 39, with a Megaball of 7. Twenty ticket holders will win $1 million after matching all the numbers except the Megaball.Strong sales boosted the jackpot to $636 million from the previous estimate of $586 million, lottery officials announced late Tuesday morning. That's tantalizingly close to the U.S. record -- a $656 million Mega Millions jackpot split by three winning tickets in March 2012.

This jackpot was so large in part because Mega Millions became tougher to win. The prize rises with each miss, and no one had won it since organizers increased the pool of numbers to choose from -- making astronomical odds even longer -- in October. The winning tickets were sold at Jenny's Gift Shop in a San Jose strip mall and a Gateway Newstand in the lobby of an office building near Atlanta's Buckhead area, lottery officials said.

In Florida, $8,000 worth of tickets were sold every minute from 9 to 10 a.m. Tuesday, CNN affiliate WFTS reported, citing lottery officials. Mega Millions tickets go for $1 each, though buyers choose to pay an additional $1 for the Megaplier option, which could multiply lesser, non-jackpot winning prizes.Before the drawing, a lottery player in the Bronx joked Tuesday that the jackpot wouldn't change his life.

"It would just change my vocabulary. I would say, 'I quit' (my job)," he told CNN affiliate News 12 of New York on Tuesday morning in the Bronx's Hunts Point neighborhood. At Bunny's Superette in Manchester, New Hampshire, a clerk told CNN affiliate WMUR that Mega Millions sales were brisk Tuesday -- she'd gone through four rolls of ticket paper by noon.

One player there, Armand Lesage, said he'd like to use the jackpot to escape snowy New Hampshire for a warm vacation. But he'd also share with his large family."My mother had 19 of us, and that is a big family, and 14 are still living," he told WMUR.The chance of winning -- never particularly bright -- got worse in late October, when Mega Millions increased the drawing's pool of numbers. The odds of hitting the jackpot, which were 1 in 176 million, are now 1 in 259 million.You have more than 1,000 times better chance of an asteroid or comet killing you -- and that's using the longest estimated odds for the celestial bodies -- according to Tulane University."Winning the Mega Millions is akin to getting struck by lightning at the same time you're being eaten by a shark," said Todd Northrop, founder of Lotterypost.com.$800 million in lottery prizes unclaimed

Previously, lottery players chose five numbers, ranging from 1 to 56. It's now 1 to 75. But the sixth, gold ball has fewer numbers from which to choose, as the pool decreased from 46 to 15.Mega Millions tickets are sold in 43 states -- all but Alabama, Alaska, Hawaii, Mississippi, Nevada, Utah and Wyoming -- plus the District of Columbia and the U.S. Virgin Islands.