SCIENCE & TECHNOLOGY

Amateur first to spot big bang on Jupiter
Steve Connor
Anthony Wesley was engaged in his favourite backyard pastime of watching Jupiter through his 14.5-inch-wide Newtonian telescope when the amateur Australian astronomer made the discovery of a lifetime – a find that has astonished and enthralled professional planet watchers around the world.

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Spacewalkers complete Japan’s laboratory complex
Organic food is no healthier, study finds


Prof Yash Pal

Prof Yash Pal

THIS UNIVERSE 
PROF YASH PAL
Why are we advised not to see the sun during a solar eclipse? The same advice is, however, not given during a common sunny day, although it very difficult to see the sun at any time. Is there anything special on the day of the solar eclipse

 


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Amateur first to spot big bang on Jupiter
Steve Connor

Anthony Wesley posing with his telescope
Anthony Wesley posing with his telescope

Anthony Wesley was engaged in his favourite backyard pastime of watching Jupiter through his 14.5-inch-wide Newtonian telescope when the amateur Australian astronomer made the discovery of a lifetime – a find that has astonished and enthralled professional planet watchers around the world.

It was just after midnight on Sunday and Mr Wesley, a 44-year-old IT consultant living in the rural town of Murrumbateman near Canberra, was about to call it a night after the clear skies he had enjoyed that evening began to deteriorate and visibility fell.

But having gone inside and got caught up watching golfer Tom Watson almost make history in the Open on television, something made Mr Wesley return to the computer screen of his home-made telescope once more. It was then he saw the dark disfiguration of a region near to Jupiter’s south pole, a part of the planet that he knew well from his many hours of painstaking observations.

“When I came back to my ‘scope at about 12.40am, I noticed a dark spot rotating into view in Jupiter’s south polar region (and) started to get curious. When first seen... it was only a vaguely dark spot, I thought likely to be just a normal dark polar storm,” Mr Wesley recorded in his observation report.

“However, as it rotated further into view, and the conditions improved, I suddenly realised that it wasn’t just dark, it was black in all channels, meaning it was truly a black spot,” he said.

His first thought was that it was one of Jupiter’s darker moons, such as Callisto, or at least the shadow from such a moon. “But it was in the wrong place and the wrong size. Also, I had noticed it was moving too slow to be a moon or shadow,” he said. “As far as I could see it was rotating in sync with a nearby white oval storm that I was very familiar with – this could only mean that the black feature was at the cloud level and not a projected shadow from a moon. I started to get excited.”

For the next 15 minutes Mr Wesley furiously checked his photographs of the same region taken just two days before. There was no sign of the black spot. It was then he realised the full magnitude of his discovery – he had witnessed the immediate aftermath of a cosmic collision between Jupiter and some as-yet-unidentified object.

Mr Wesley remembered one of the most famous cosmic impacts in recent times, when the comet Shoemaker-Levy pounded Jupiter exactly 15 years ago with the explosive power of thousands of nuclear bombs. “I remember watching Jupiter back then, so I grew up with those images,” he said.

“Could it really be an impact mark on Jupiter? I had no real idea, and the odds on that happening were so small as to be laughable, but I was really struggling to see any other possibility given the location of the mark. If it really was an impact mark then I had to start telling people, and quickly,” he said.

The “surreal” experience of seeing the same sort of image again spurred him into action. He quickly fired off emails to the international astronomical community and the US National Aeronautics and Space Administration (Nasa).

Glenn Orton of Nasa’s Jet Propulsion Laboratory in California used a high-powered infrared telescope on a mountaintop in Hawaii to confirm the sighting. The dark spot was accompanied by bright “upwelling particles” in the upper atmosphere of Jupiter, with the possible emission of ammonia gas, – the tell-tale signs of a massive impact.

It was clear that Jupiter had been hit, although Dr Orton and his Nasa colleagues were not sure whether it was by a comet or some other celestial object. “It could be the impact of a comet, but we don’t know for sure yet,” Dr Orton said.

“We were extremely lucky to be seeing Jupiter at exactly the right time, the right hour, the right side of Jupiter to witness the event,” he said.

By arrangement with The Independent
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Spacewalkers complete Japan’s laboratory complex

Astronaut Christopher Cassidy participates in the mission’s fifth and final session of extravehicular activity in this NASA handout photo taken on July 27, 2009.
Astronaut Christopher Cassidy participates in the mission’s fifth and final session of extravehicular activity in this NASA handout photo taken on July 27, 2009. —Reuters

CAPE CANAVERAL, Florida: A pair of spacewalking astronauts put the finishing touches on Japan’s International Space Station research lab Monday during a fifth and final outing before the visiting shuttle Endeavour departs. Floating 225 miles above Earth, Endeavour astronauts Chris Cassidy and Tom Marshburn outfitted Japan’s new outdoor experiments platform with television cameras, completing the $2.4-billion Kibo complex.




Organic food is no healthier, study finds

LONDON: Organic food has no nutritional or health benefits over ordinary food, according to a major study. Researchers from the London School of Hygiene and Tropical Medicine said consumers were paying higher prices for organic food because of its perceived health benefits, creating a global organic market worth an estimated $48 billion in 2007.— Reuters
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THIS UNIVERSE 
PROF YASH PAL

Why are we advised not to see the sun during a solar eclipse? The same advice is, however, not given during a common sunny day, although it very difficult to see the sun at any time. Is there anything special on the day of the solar eclipse

I do not think there is any thing special about an eclipse day, except for the fact that for some time the moon shadows the solar disc. There are no extra radiations. However the difference lies in our great curiosity to observe the gradual covering of the sun and the spectacle that can be observed before, during and soon after totality. A greater danger to the eyes comes from the fact that we have a tendency to stare at the sun during this time, which we normally don’t. Also the fact that during totality, the iris of our eye is totally open and therefore lets in lot of sunlight when the sun suddenly appears. This can be dangerous, unless we are careful.

Since you have asked about the special aspects of the eclipse, I might remind you that the total solar eclipse happens on a new moon day at a time when the moon orbit is crossing the ecliptic, the plane in which the sun goes around the sun. This is the reason that we do not have an eclipse every new moon day.

Do changes in salinity in oceans affect the climate?

I am also not an expert in this area, but it would be interesting to explore this question a little. You perhaps know that the ocean currents are very important for maintaining the temperature differences on the planet. The Western part of Europe would have been much colder than it is if it were not for the fact that the Gulf Stream goes by Great Britain carrying warmer waters from the tropical areas. This ocean current is driven by the prevailing winds. It is obvious that water cannot be traveling across the Atlantic to Europe to pile up there. There must be a path to return the water that is going there. It is believed that this path is provided by the fact that after being cooled in the Arctic region, the water in the current becomes heavier and sinks deep in the ocean and starts moving backwards along the coast of America. This must rise up again near the Equator and go on another journey. Indeed without this “conveyor belt” of ocean currents climate in different parts of the world would be very different.

Let us get back to your question. What is the possible role of salinity of the sea in all this? For this let us go back to the events that happen when the Gulf Stream comes close to the Arctic Ocean. It is true that the water after cooling down sinks to the lower layer’s return path in the ocean. It is possible that this sinking is helped by the fact that lot of water coming up with the Gulf Stream might also be freezing in Arctic cold. If so, another natural happening could play an important role in keeping the conveyor belt going. This is the fact that saline water while freezing has to let go most of its salt load to liquid water, making it heavier and thus helping it to sink to lower depth to join the current going on the return path. We have to remember that pure ice in the Arctic, Antarctic, and glaciers of Norway and Greenland is pure water.

The above discussion indicates that salinity might have a significant role in maintaining, or altering climate on the planet. Could the onset and recession of Ice Ages might have had something to influences like this? I do not know.

I think this area is still open scientifically. Suppose a lot of melting of ice in the Arctic Ocean and increased flows of fresh water from Norway and melting of Greenland ice makes the last stage of the Gulf Stream a bit cold, but salt-less. Is it possible that this salt-less water becomes rather light and therefore unwilling to sink down to lower depths? If yes, then there would be a block to the movement of the current and the conveyor belt might slow down and actually stop! That would be catastrophic for Europe and many other parts of the world. Another Ice Age might begin!

Why is water not inflammable even though it is made of two substances which enhance the rate of combustion—oxygen and hydrogen?

You know that when hydrogen burns, it combines with oxygen. This is like most burning. The difference is that there is a single product of this burning. That is nothing but water. In a real sense water represents the ash of hydrogen burning. It should then be clear that the ashes of burning cannot start burning again. Water cannot combine with oxygen to produce energy.


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