Closest Encounter with Jupiter until 2022 link

Sept. 15, 2010:  Been outside at midnight lately? There's something you really need to see. Jupiter is approaching Earth for the closest encounter between the two planets in more than a decade--and it is dazzling. The night of closest approach is Sept. 20-21st. This is also called "the night of opposition" because Jupiter will be opposite the sun, rising at sunset and soaring overhead at midnight. Among all denizens of the midnight sky, only the Moon itself will be brighter.

Science@NASA reader Tamas Ladanyi took this picture of a friend photographing Jupiter over a lake in the Bakony mountains of Hungary on Sept. 5th. "The giant planet was remarkably bright," says Ladanyi. [larger image]

Earth-Jupiter encounters happen every 13 months when the Earth laps Jupiter in their race around the sun. But because Earth and Jupiter do not orbit the sun in perfect circles, they are not always the same distance apart when Earth passes by. On Sept. 20th, Jupiter will be as much as 75 million km closer than previous encounters and will not be this close again until 2022.
The view through a telescope is excellent. Because Jupiter is so close, the planet's disk can be seen in rare detail--and there is a lot to see. For instance, the Great Red Spot, a cyclone twice as wide as Earth, is bumping up against another storm called "Red Spot Jr." The apparition of two planet-sized tempests grinding against one another must be seen to be believed.

Jupiter's "kissing red spots" photographed by Alan Friedman of Buffalo, NY, using a 10-inch telescope. The full-sized image shows the golden disk of Jupiter's moon Io.

Also, Jupiter's trademark South Equatorial Belt (SEB) recently vanished, possibly submerging itself beneath high clouds. Researchers say it could reappear at any moment. The dramatic resurgence would be accompanied by a globe-straddling profusion of spots and cloudy swirls, clearly visible in backyard telescopes.
And what was that flash? Amateur astronomers have recently reported a surprising number of fireballs in Jupiter's atmosphere. Apparently, many small asteroids or comet fragments are hitting the giant planet and exploding among the clouds. Researchers who have studied these events say visible flashes could be occurring as often as a few times a month.
Finally, we mustn't forget the moons of Jupiter because they are also having a close encounter with Earth. These are planet-sized worlds with active volcanoes (Io), possible underground oceans (Europa), vast fields of craters (Callisto), and mysterious global grooves (Ganymede). When Galileo discovered the moons 400 years ago, they were no more than pinpricks of light in his primitive spy glass. Big, modern amateur telescopes reveal actual planetary disks with colorful markings.
It makes you wonder, what would Galileo think?
Answer: "I'm getting up at midnight!"

 

Stadium lies in ruins after roof caves-in due to heavy snow in New Zealand ~ link ~

Heavy snow has severely damaged one of Invercargill's most important venues.

The weight of snow caused the roof on the main netball court to collapse at the multi-purpose and world-class Stadium Southland this morning.

Stadium Southland General Manager Nigel Skelt said it was lucky it did not happen during a busy time of week.

"We've never had a snow fall this big before, in our history. We've been going ten years and unfortunately in this instant it just hasn't been able to sustain it.

"The result could've been far more catastrophic."

September snow surprise in Montana ~ link ~ Snow began falling in some areas of north central Montana and along the Rocky Mountain Front early on Friday, leaving some people checking their calendar to see if it is still, in fact, summer.

A rain-snow mix in and around Great Falls turned to all snow around 10 am in some areas. Up to an inch of accumulation may be possible throughout Friday, and temperatures will remain in the upper 30s to low 40s.

While snow in September is not unusual at higher elevations and in Glacier National Park, many lower elevations also received a dusting, with some areas reporting several inches of snow by mid-day on Friday.

 

Return of La Niña

by admin on Sep.19, 2010, under International News

The cold stretch of the thermal oscillation in the Pacific could make its presence felt this winter.

As El Niño’s cooler sister rolls round again, Nature probes the environmental pros and cons.
La Niña, the climatic event in which swathes of the equatorial east-central Pacific cool, strengthened through August, according to reports from the US National Oceanic and Atmospheric Administration (NOAA). Across all latitudes monitored by the NOAA, the ocean surface cooled by 1.3–1.8 ºC. Models predict that La Niña will persist until at least early 2011, and could, according to the NOAA, cool further during the coming winter. Nature explores its potential effects on the global environment.
What is the scientific definition of La Niña?
La Niña is a natural 3–6-year cycle, and the cold stretch of a periodic thermal oscillation in ocean surface temperatures that occurs throughout the tropical Pacific. Along with the better-known warming event, El Niño, it involves a difference from average water temperatures of more than 0.5 ºC. La Niña can persist for 1-3 years, as seen, for example, in 1998–2000.
What are its key global impacts?
Ocean cooling affects tropical Pacific rainfall from Indonesia to South America, says Gerry Bell, a NOAA climate scientist at the Climate Prediction Center in Camp Springs, Maryland. Some places, such as northern Australia, experience wetter than average seasons. “The changes are so large that it affects wind, too,” adds Bell, “and right downstream of this area is the Atlantic.”
Does this have implications for the Atlantic hurricane season?
La Niña reduces variations in wind speed and direction throughout the atmosphere, which makes Atlantic hurricanes likelier, Bell says. This year may be particularly active, he adds. On top of La Niña, Atlantic water temperatures have remained unusually high over the past 15 years, and wind patterns that have been in place since 1995 — such as weak easterly trade winds and high pressure in the upper atmosphere — are particularly conducive to a strong hurricane season. NOAA expects 8–12 Atlantic hurricanes this season, of which it predicts 4–6 will be major hurricanes (that is, with sustained wind speeds of more than 178 km h–1).
Will La Niña help to lower global temperatures after recent record highs?
Average temperature over land outside the tropical regions of the Northern Hemisphere reached a new high in July 2010, according to a report by the European Centre for Medium-Range Weather Forecasts. In addition, the global average over land during the previous 12 months ranks as the second highest on record. La Niña conditions have offset these highs, but have mainly affected tropical Pacific waters. Global temperatures have been rising since the turn of the twentieth century, most notably during the past 30 years, but La Niña is part of a regular cycle that is simply overlaid onto that pattern.

How strong is this La Niña event compared with previous ones?
So far, La Niña has been relatively strong this summer. “That’s not unheard of,” says Bell, adding that similar conditions in 1998 made headlines. The oscillation usually begins to strengthen during the autumn, so it remains to be seen how much more powerful this year will be compared with previous years.

Why is it important to keep track of these events?
Knowledge of how La Niña affects global weather patterns can help governments and people to plan for drought or heavy rainfall. For instance, researchers know that the Pacific Northwest is likely to be wetter than normal in the late autumn and early winter of La Niña years, which helps to refill parched aquifers in the wake of dry periods. Predicting global-temperature oscillations is crucial to water management, as well as to farmers seeking to mitigate potential losses.