Moon and planets offer triple treat on Friday

Look toward the southwestern horizon just after sunset on Friday night and you’ll see a triple feature of Venus, Mercury, and the two-day old moon. And there's another planet treat in time for the pre-Halloween weekend, too.

You'll need a good low horizon and a clear sky to see the first three objects since they will be very low in the sky, less than 10 degrees up. Binoculars may help. For reference, a closed first held out at arm's length covers about 10 degrees of the night sky.

The accompanying sky map of the moon and planets here shows their locations on Friday evening.

The moon will be a razor-thin crescent, and the so-called "dark" side of the moon — actually its far side facing away from Earth, which is not always dark — should be well lit by sunlight reflecting off the Earth.

Venus should appear very bright, weather permitting. This may be the first glimpse you get of it this season, but it will soon be blazing bright every evening. Mercury will be directly under Venus.

All three objects will be very low because of the shallow angle the ecliptic — the path the sun takes across the sky — makes with the horizon on Friday. Notice that the sun is setting well to the south of the west point on the horizon, now that we're more than a month past the fall equinox.

The only days the sun sets due west is right on the equinoxes, which were March 20 and Sept. 23 this year.

A few minutes after sunset, turn around and look at the eastern horizon. You will see Jupiter rising there slightly north of due east, the brightest object in that part of the sky.

At 10 p.m. EDT on Friday, Jupiter will be opposition, exactly opposite the sun in the sky. On this night, Jupiter rises at sunset and sets at sunrise, so is visible all night long.

Binoculars or a small telescope can reveal Jupiter's four bright moons, allowing you to follow them as they constantly shift position, orbiting around the giant planet.

Diamond Studs

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Plenty of room on planet Earth

The world now has almost seven billion people and rising. The population may surpass nine billion by 2050. We, together with our 20 billion chickens and four billion cattle, sheep and pigs, will utterly dominate the planet. Can the planet take it? Can we take it?

Yes. Not only is such a huge population going to prove indefinitely "sustainable;" it is actually likely that the ecological impact of nine billion in 2050 will be lighter, not heavier: there will be less pollution and more space left over for nature than there is today.

Consider three startling facts. The world population quadrupled in the 20th century, but the calories available per person went up, not down. The world population doubled in the second half of the century, but the total forest area on the planet went up slightly, not down. The world population increased by a billion in the last 13 years, but the number living in absolute poverty (less than a dollar a day, adjusted for inflation) fell by around a third.

Clearly it is possible at least for a while to escape the fate forecast by Robert Malthus, the pessimistic mathematical cleric, in 1798. We've been proving Malthus wrong for more than 200 years. And now the population explosion is fading. Fertility rates are falling all over the world: in Bangladesh it's down from 6.8 children per woman in 1955 to 2.7 today; China - 5.6 to 1.7; Iran - 7 to 1.7; Nigeria - 6.5 to 5.2; Brazil 6.1 to 1.8; Yemen - 8.3 to 5.1.

The rate of growth of world population has halved since the 1960s; the absolute number added to the population each year has been falling for more than 20 years. According to the United Nations, population will probably cease growing by 2070. This miraculous collapse of fertility has not been caused by Malthusian misery or coercion (except in China), but by the opposite: enrichment, urbanization, female emancipation, education and above all the defeat of child mortality - which means women start to plan families rather than continue breeding.

Increasing prosperity means eating more food, though. Can we really feed today's let alone tomorrow's billions? In 60 years we have trebled the total harvest of the three biggest crops: wheat, rice and corn. Yet the acreage devoted to growing these crops has barely changed. This is because fertilizer, irrigation, pesticides and new varieties have greatly increased yields.

They continue to do so. Growth regulators boost the yield of wheat. Genetic modification boosts the yield of cotton (while increasing the biodiversity in fields). New enzymes promise to cut the phosphate output and increase weight gain of pigs. These technologies save rainforest by sparing land from the plow. If we went back to organic farming, the world would have to cultivate more than twice as much land as we do.

Already huge swaths of the world are being released from farming and reforested. New England is now 80 per cent woodland, where it was once 70 per cent farmland. Italy and England have more woodland than they have for centuries. Moose, coyotes, beavers and bears are back in places where they have not been for centuries. France has a wolf problem; Scotland a deer problem. It is the poor countries, not the affluent ones, that are losing forest. Haiti, with its near total dependence on renewable power (wood), is 98 per cent deforested and counting.

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Scientists Discover New Radiation Belt at Saturn

Scientists using the Cassini spacecraft's Magnetospheric Imaging instrument have detected a new, temporary radiation belt at Saturn, located around the orbit of its moon Dione at about 377,000 kilometers (234,000 miles) from the center of the planet.

The new belt, which has been named "the Dione belt," was detected by the instrument for only a few weeks on three separate occasions in 2005. Scientists believe that newly formed charged particles in the Dione belt were gradually absorbed by Dione itself and another nearby moon, named Tethys, which lies slightly closer to Saturn at an orbit of 295,000 kilometers (183,304 miles).

Mystery cause of Solar Wind Heating recognized

The solar wind is hotter than it should be, and for decades researchers have puzzled over the unknown source of energy that heats it. In a paper published in the June 12 issue of Physical Review Letters, NASA scientists say they may have found the answer.

"The energy source is turbulence," says co-author Melvyn Goldstein, chief of the Geospace Physics Laboratory at NASA's Goddard Space Flight Center, Greenbelt, Md. "The sun heats the solar wind by stirring it up."

Chandra Turns Ten

About ten years ago Space Shuttle Columbia launched hauling 55,000 pounds worth of astronomers' dreams -- the Chandra X-Ray Observatory. This was the heaviest payload a space shuttle ever lifted – and one of the best day's labor the work-horse space shuttle ever put in.

Above : In a beautiful night launch, the space shuttle (STS-93) carries Chandra aloft.



Above: Chandra's first light image of the Cas A supernova remnant.



Above: A false-color X-ray image of the Cas A supernova remnant. Red traces iron-rich material; greenish-white denotes material enriched in silicon and sulfur. The blue regions are peppered with X-ray absorbing space dust.



Above: A composite Hubble-Chandra image of the Crab Nebula. Credit: NASA and Chandra Science Center



Above: A Chandra X-ray Observatory image of the central region of our Milky Way galaxy.



Above: This Chandra image gave scientists their first look at X-rays from Mars.

Trigger-Happy Star Formation

This composite image, combining data from the Chandra X-ray Observatory and the Spitzer Space Telescope shows the molecular cloud Cepheus B, located in our Galaxy about 2,400 light years from the Earth. A molecular cloud is a region containing cool interstellar gas and dust left over from the formation of the galaxy and mostly contains molecular hydrogen. The Spitzer data, in red, green and blue shows the molecular cloud (in the bottom part of the image) plus young stars in and around Cepheus B, and the Chandra data in violet shows the young stars in the field.

Clementine

This image was taken by Clementine as it came over the north lunar pole at the completion of mapping orbit 102 on March 13, 1994. The angular separation between lunar horizon and Earth has been reduced for illustration purposes. The large crater at the bottom of the image is Plaskett (180 W longitude, 82 N latitude).

NASA Honors Apollo Astronaut Al Worden with Moon Rock

WASHINGTON -- NASA will honor Apollo astronaut Al Worden with the presentation of an Ambassador of Exploration Award for his contributions to the U.S. space program.

Worden will receive the award during a ceremony Thursday, July 30, at 4 p.m. EDT. The ceremony will be held at the Apollo Saturn V Center at NASA's Kennedy Space Center Visitor Complex in Florida, where the moon rock will be displayed.

Reporters interested in covering the ceremony should contact Andrea Farmer at 321-449-4318 or Jillian McRae at 321-449-4273.

NASA is giving the Ambassador of Exploration Award to the first generation of explorers in the Mercury, Gemini and Apollo space programs for realizing America's goal of going to the moon. The award is a moon rock encased in Lucite, mounted for public display. The rock is part of the 842 pounds of lunar samples collected during six Apollo expeditions from 1969 to 1972. Those astronauts who receive the award will then present the award to a museum of their choice, where the moon rock will be placed for public display.

Worden served as command module pilot for the Apollo 15 mission, which set several moon records for NASA, including the longest lunar surface stay time, the longest lunar extravehicular activity and the first use of a lunar roving vehicle. Worden spent 38 minutes in a spacewalk outside the command module and logged a total of 295 hours, 11 minutes in space during the mission.

Worden was born in Jackson, Mich. He received a bachelor of military science degree from the United States Military Academy at West Point, N.Y., in 1955, and master of science degrees in astronautical and aeronautical engineering and instrumentation engineering from the University of Michigan in 1963.

New NASA Images Indicate Object Hits Jupiter

Scientists have found evidence that another object has bombarded Jupiter, exactly 15 years after the first impacts by the comet Shoemaker-Levy 9.

Following up on a tip by an amateur astronomer, Anthony Wesley of Australia, that a new dark "scar" had suddenly appeared on Jupiter, this morning between 3 and 9 a.m. PDT (6 a.m. and noon EDT) scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., using NASA's Infrared Telescope Facility at the summit of Mauna Kea, Hawaii, gathered evidence indicating an impact.

New infrared images show the likely impact point was near the south polar region, with a visibly dark "scar" and bright upwelling particles in the upper atmosphere detected in near-infrared wavelengths, and a warming of the upper troposphere with possible extra emission from ammonia gas detected at mid-infrared wavelengths.

"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. We couldn't have planned it better," said Glenn Orton, a scientist at JPL.

Orton and his team of astronomers kicked into gear early in the morning and haven't stopped tracking the planet. They are downloading data now and are working to get additional observing time on this and other telescopes.

This image was taken at 1.65 microns, a wavelength sensitive to sunlight reflected from high in Jupiter's atmosphere, and it shows both the bright center of the scar (bottom left) and the debris to its northwest (upper left).

"It could be the impact of a comet, but we don't know for sure yet," said Orton. "It's been a whirlwind of a day, and this on the anniversary of the Shoemaker-Levy 9 and Apollo anniversaries is amazing."

Shoemaker-Levy 9 was a comet that had been seen to break into many pieces before the pieces hit Jupiter in 1994.

Leigh Fletcher, a NASA postdoctoral fellow at JPL who worked with Orton during these latest observations said, "Given the rarity of these events, it's extremely exciting to be involved in these observations. These are the most exciting observations I've seen in my five years of observing the outer planets!"

The observations were made possible in large measure by the extraordinary efforts of the Infrared Telescope Facility staff, including telescope operator William Golisch, who adroitly moved three instruments in and out of the field during the short time the scar was visible on the planet, providing the wide wavelength coverage.

JPL is managed for NASA by the California Institute of Technology in Pasadena.