The Square Kilometre Array: Divide And Rule
The world’s biggest astronomy project is split between Africa and Australasia. That gives South Africa, in particular, a chance to show its scientific mettle.
(Radio dishes look skyward. Credit: AFP)
“THE reputation of physics as the queen of sciences is reflected in the amount of money that governments are willing to spend on it. The Large Hadron Collider, Europe’s latest particle smasher, cost around $9 billion and took a decade to build. But, just occasionally, other fields get to play with some big, taxpayer-funded kit of their own, too.”
“On May 25th it was the astronomers’ turn in the limelight. For several years two groups of countries, one consisting of Australia and New Zealand, and the other of several sub-Saharan nations led by South Africa, have been polishing their rival bids to host the Square Kilometre Array, a gargantuan, €1.5 billion ($1.9 billion) radio telescope first proposed in 1991 and designed to be the most sensitive ever constructed. After months of deliberation, the SKA’s funding nations announced their decision: that the telescope would be split, and both groups would host a bit of it.”
“That the funding nations felt able to split the telescope in half reflects how closely matched the two bids were. Both consortia had constructed precursor telescopes that could be integrated into the SKA itself, and each bid had its advantages. The African bid, whose core will be in Northern Cape province, did well in the technical stakes, chiefly because the geography of the area allows a more efficient layout for the telescope, and also because electricity was thought likely to be cheaper there. The SKA will use about 110 megawatts when up and running, so power bills will be a significant expense. The Australasian bid, centred on the virtually unpopulated Shire of Murchison, in Western Australia, scored better for radio quietness (important to prevent interference), and on non-scientific factors such as political stability and the quality of the working environment.”
(Word on the street is that much of the decision of locating SKA came down to politics and was not as driven by the science requirements. The Economist story touches on this: “[M]any people—including Naledi Pandor, South Africa’s science minister, who said as much in an official statement—reckon that the decision had more to do with politics than science.” This is the nature of international collaboration: only by merging budgets is such blockbuster science possible, but it comes at a matching high political price. Politics driving science may be the new reality of the 21st century. -JCB)
Excitement builds for rare transit of Venus on June 5
Scientists are gearing up for the upcoming transit of Venus, an extremely rare opportunity to watch the planet Venus pass in front of the sun as seen from Earth. Venus is due to make this cosmic crossing June 5-6 — the last time such an event will occur until 2117.
(The 2004 transit of Venus. Credit: Imelda B. Joson and Edwin L. Aguirre)
“When viewed through special solar filters or protective equipment, the transit should offer skywatchers and amateur astronomers an unforgettable sight, weather permitting. But the event is also a rare opportunity for scientists.”
“As Venus transits the sun, sunlight will be filtered through the planet’s atmosphere. By analyzing the absorption features in this light, researchers can learn more about the chemical elements present in the gaseous haze around Venus. Many of the world’s premier telescopes will be trained on the sight, including NASA’s Hubble Space Telescope and Solar Dynamics Observatory, as well as the European Space Agency’s Venus Express satellite in orbit around Venus.”
“Because of the peculiarities of the orbits of the planets around the sun, Venus transits are visible from Earth in pairs separated by eight years. The upcoming transit is the second in a pair that began with one in 2004, which at the time was the first visible in more than 121 years. The 2004 transit provided scientists with the first opportunity to view such an event with modern equipment and telescopes.”
(Skywatchers will want to make every effort to SAFELY observe next week’s Venus transit, the last time such an event will occur likely during the lifetime of anyone alive today. Full details, including maps and times of visibility, are available at transitofvenus.org. However, DO NOT LOOK DIRECTLY AT THE SUN without a proper filter! Viewing the Sun directly can cause damage or permanent loss of vision! Among the safest ways to view the Sun is through a layer of Number 14 welder’s glass, available from specialty welding supply stores — do not use a less dense type of welder’s glass than Number 14. Alternately, an image of the Sun can be safely viewed with a pinhole viewer out of a shoebox and some aluminum foil. -JCB)
Source: kenobi-wan-obi
Catch a Glimpse of Halley's Comet Debris - Eta Aquarid Meteor Shower
See dust shed long ago by the infamous Comet Halley as it streaks through the upper atmosphere at nearly 100,000 miles per hour, lighting up the night sky.
(An Eta Aquarid meteor streaks over northern Georgia on April 29, 2012. Credit: NASA/MSFC/B. Cooke)
“Each spring as Earth passes through the debris trail from Halley’s Comet (1P/Halley), the cosmic bits burn up in our atmosphere and result in the annual Eta Aquarid meteor shower. This year the peak will occur on the night of May 5 and into the morning of May 6, with meteor rates of about 40-60 meteors per hour under ideal conditions.”
“The Eta Aquarids are pieces of debris from Halley’s Comet, which is a well-known comet that is viewable from Earth approximately every 76 years. Also known as 1P/Halley, this comet was last viewable from Earth in 1986 and won’t be visible again until the middle of 2061. The annual Eta Aquarid meteor shower gets its name because the radiant - or direction of origin - of the meteors appears to come from the constellation Aquarius.”
“A full moon occurs on May 6, just a day after the Eta Aquarids’s peak on the 5th. The light of the bright full moon will wash out the fainter Eta Aquarid meteors, but all is not lost! The Etas have a decent rate - 60 per hour - and contain quite a few fireballs.”
A Good Year for Lyrid Meteors
Although typically weak, the annual Lyrid display will benefit from moonless skies and a peak on the morning of April 22nd that favors North America.
(The Lyrid shower’s radiant rises as early as 10 p.m., but you’ll likely see more meteors once it climbs much higher in the sky before dawn. Credit: Sky & Telescope)
“Among the widely recognized annual meteor showers, the Lyrid display that arrives every April is seldom very dramatic. Usually the Lyrids produce only about a dozen meteors per hour under dark skies. The shower is due to peak on the morning of Sunday, April 22nd, around 5hor 6h Universal Time according to the International Meteor Organization. This corresponds to 1 or 2 a.m. EDT — excellent timing for North America.”
“The Lyrids get their name from the constellation Lyra, as they appear to radiate from a point near the bright star Vega. They are bits of interplanetary dust shed by Comet Thatcher (C/1861 G1) and scattered along its orbit, which Earth crosses every April. The particles strike our atmosphere at 30 miles (49 km) per second, and they typically create momentary streaks as bright as the stars in the Big Dipper.”
(While the Lyrids aren’t the most spectacular of the annual meteor showers, they’re pretty reliable. The good news is that this year there is zero moonlight interference, which will make seeing the meteors easier. Comet Thatcher, last seen during the early days of the American Civil War, has a period of about 415 years; it will next grace the skies of Earth — and refresh the particle stream responsible for the Lyrid shower — in around the year 2276. -JCB)
Night sky over the position of the wreck of the RMS Titanic (41° 43’N, 49°56’W) at 2:20 am local time, 15 April 1912.
This is the view victims and survivors would have had when the ship disappeared beneath the waves.
The view is looking straight overhead with the zenith in the center, and the horizon represented by a circle near the edge of the frame (with the azimuth in degrees marked along it). North is at the top, and east and west are revered compared to the orientation of maps, because the view is up into the sky rather than down from overhead.
The night of Titanic’s loss was very dark on account of there being no Moon in the sky. The sea was exceptionally calm, leading to virtually mirror-like reflections off its surface. Notable, bright objects in the local night sky were the stars Arcturus, Vega, Spica, Altair, and Antares. Capella was setting on the northern horizon at the time of the sinking, at an azimuth of about 340°. Most prominent in the sky was Jupiter, low in the south-southeast.
However, film director James Cameron famously got this sky wrong in the 1997 film Titanic; the affected scene appeared to show the Milky Way passing directly overhead, which was certainly not the case. Astronomer Neil de Grasse Tyson pointed out the inaccuracy to Cameron, and replacing the sky with the correct one was the only change made before the film’s recent 3-D re-release.
Mars Viking Robots ‘Found Life’
New analysis of 36-year-old data, resuscitated from printouts, shows NASA found life on Mars, an international team of mathematicians and scientists conclude in a paper published this week.
Further, NASA doesn’t need a human expedition to Mars to nail down the claim, neuropharmacologist and biologist Joseph Miller, with the University of Southern California Keck School of Medicine, told Discovery News.
“The ultimate proof is to take a video of a Martian bacteria. They should send a microscope — watch the bacteria move,” Miller said.
“On the basis of what we’ve done so far, I’d say I’m 99 percent sure there’s life there,” he added.
(If confirmed, obviously this would be very big news indeed. Researchers in the 1970’s concluded that weird soil chemistry was responsible for the evidently positive results from the life experiments on Viking. Clays in the Martian soil, so the explanation went, were subject to prolonged irradiation by ultraviolet light from the Sun, undergoing chemical changes that provoked the observed changes when, e.g., a nutrient solution onboard the Viking landers was added to soil samples. Some never accepted that explanation, and are still seeking a definitive answer. But, as Carl Sagan once reminded us, “Extraordinary claims require extraordinary evidence.” Stay tuned… -JCB)
The Moon Visits Jupiter and Venus
The crescent Moon visits Jupiter in the evening sky on Sunday, March 25th, and it visits Venus on Monday night.
“The Moon will visit Venus two more times before Venus’s historic transit across the Sun’s face on June 5th, but this is your last chance to see Jupiter paired with the Moon high in a dark night sky for several months. A very thin crescent Moon will hang above Jupiter shortly after sunset on April 22nd, but the pair will be very low in bright twilight.”
The best part is that no telescope or even binoculars are needed to see this sight! Also, as the sky is darkening, look for bright, red Mars rising in the eastern sky almost exactly opposite the Moon/Jupiter/Venus spectacle. Toward midnight, Saturn will rise in the east, near the bright blue star Spica. That’s four bright planets in one night! -JCB
Venus Spacecraft Punched, Blinded by Solar Radiation
Space weather in our solar system has been rather unsettled of late, and some of our tenacious robotic interplanetary explorers have been feeling the impact of the sun’s temper tantrums. The European Space Agency’s Venus Express orbiter suffered a particularly nasty solar sucker-punch, temporarily blinding one of its navigational systems.
The solar radiation hit Venus’ orbit on March 7 (Tuesday) after the sun had belched out a series of solar flares and coronal mass ejections (CMEs). This radiation uptick knocked-out Venus Express’ startracker cameras (including the backup camera), causing them to lose sight of stars the spacecraft uses to orient itself.
Astronomy news, recent research results, and pretty pictures from the media along with context, commentary, and explanations for folks who dig this sort of thing. Written by a quasi-professional astronomer affiliated with the University of Texas at Austin.
