Astronews - February 2005

Einstein@Home - Search For Gravitational Waves

 

You may have already tried out SETI@home. Now Einstein@Home will let anyone with a PC contribute to cutting edge astrophysics research!



Einstein@Home is a flagship program of the World Year of Physics 2005 celebration of the centennial of Albert Einstein's miraculous year. The program searches for gravitational waves in data collected by US and European gravitational wave detectors.

Albert Einstein's General Theory of Relativity predicted the existence of gravitational waves in 1916, but only now has technology reached the point that scientists hope to detect them directly.

Gravitational waves?? They are ripples in the fabric of space and time produced by violent events in the universe such as black hole collisions and exploding stars (supernovae).

Longer-lived sources of gravitational waves include rapidly rotating compact stars, and binary systems composed of two orbiting stars. The ripples travel through space, carrying information both about their source and about the nature of gravity itself.

Finding such signals in gravitational wave data requires an enormous amount of computing power. Estimates indicate that searching gravitational data with the maximum possible sensitivity would require many times the computing capacity of even the most powerful supercomputer.

Therefore, LIGO Scientific Collaboration researchers from the Albert Einstein Institute, UWM, and the LIGO Laboratory are enlisting the aid of an army of home computer users to analyze the data.

Much like the popular SETI@Home project that searches radio telescope data for signs of extraterrestrial life, Einstein@Home will involve hundreds of thousands people who will dedicate a portion of their personal computers' computational time to the project.

The Einstein@Home program is available for PCs running Windows, Linux, and Mac operating systems. When the computer is not in use, it downloads LIGO and GEO600 data from a central server and searches it for gravitational wave signals. While running, it displays a screensaver that depicts the celestial sphere, with the major constellations outlined. A moving marker indicates the portion of the sky currently being searched on the computer.

Happy hunting!

Einstein@home website:
http://einstein.phys.uwm.edu/

 

Full Moon Names

 

Naming the full moons - a Tradition dating back to Native American tribes



Full Moon names date back to Native Americans. Tribes kept track of the seasons by giving distinctive names to each recurring Full Moon.

Their names were applied to the entire month in which each occurred. In general the same names were current throughout the Algonquin tribes from New England on west to Lake Superior. European settlers followed their own customs and created some of their own names.

Since the lunar ("synodic") month is roughly 29.5 days in length on average, the dates of the Full Moon shift from year to year.

Below are all the Full Moon names for 2005, as well as the dates and times (USA Eastern time zone).

January 25, 5:32 a.m. EST --The Full Wolf Moon.

Amid the zero cold and deep snows of midwinter, the wolf packs howled hungrily outside Indian villages. It was also known as the Old Moon or the Moon After Yule. In some tribes this was the Full Snow Moon; most applied that name to the next moon.

February 23, 11:54 p.m. EST --The Full Snow Moon.

Usually the heaviest snows fall in this month. Hunting becomes very difficult, and hence to some tribes this was the Full Hunger Moon.

March 25, 3:58 p.m. EST --The Full Worm Moon.

In this month the ground softens and the earthworm casts reappear, inviting the return of the robins. The more northern tribes knew this as the Full Crow Moon, when the cawing of crows signals the end of winter, or the Full Crust Moon because the snow cover becomes crusted from thawing by day and freezing at night. The Full Sap Moon, marking the time of tapping maple trees, is another variation. This is also the Paschal Full Moon; the first full Moon of the spring season.

April 24, 6:06 a.m. EDT --The Full Pink Moon.

The grass pink or wild ground phlox is one of the earliest widespread flowers of the spring. Other names were the Full Sprouting Grass Moon, the Egg Moon, and -- among coastal tribes -- the Full Fish Moon, when the shad came upstream to spawn.

May 23, 4:18 p.m. EDT --The Full Flower Moon.

Flowers are abundant everywhere. It was also known as the Full Corn Planting Moon or the Milk Moon.

June 22, 12:14 a.m. EDT --The Full Strawberry Moon.

Known to every Algonquin tribe. Europeans called it the Rose Moon.

July 21, 7:00 a.m. EDT --The Full Buck Moon.

So-called because it is when the new antlers of buck deer push out from their foreheads in coatings of velvety fur. It was also often called the Full Thunder Moon, thunderstorms being now most frequent. Sometimes also called the Full Hay Moon.

The Moon will also be at perigee later this day, at 4:00 p.m., at a distance of 221,928 mi./357,158 km miles from Earth. Very high ocean tides can be expected from the coincidence of perigee with full Moon.

August 19, 1:53 p.m. EDT --The Full Sturgeon Moon

So-called because it is when this large fish of the Great Lakes and other major bodies of water like Lake Champlain is most readily caught. A few tribes knew it as the Full Red Moon because the moon rises looking reddish through sultry haze, or the Green Corn Moon or Grain Moon.

September 17, 10:01 p.m. EDT --The Full Harvest Moon.

Traditionally, this designation goes to the Full Moon that occurs closest to the Autumnal (Fall) Equinox. In two years out of three, the Harvest Moon comes in September, but every third year it occurs in October. At the peak of the harvest, farmers can work into the night by the light of this moon.

Usually the full Moon rises an average of 50 minutes later each night, but for the few nights around the Harvest Moon, the Moon seems to rise at nearly the same time each night: just 25 to 30 minutes later across the U.S., and only 10 to 20 minutes later for much of Canada and Europe. Corn, pumpkins, squash, beans, and wild rice -- the chief Indian staples -- are now ready for gathering.

October 17, 8:14 a.m. EDT --The Full Hunter’s Moon.

With the leaves falling and the deer fattened, it is time to hunt. Since the fields have been reaped, hunters can ride over the stubble, and can more easily see the fox, also other animals, which have come out to glean and can be caught for a thanksgiving banquet after the harvest.

November 15, 7:58 p.m. EST --TheFull Beaver Moon.

Time to set beaver traps before the swamps freeze to ensure a supply of warm winter furs. Another interpretation suggests that the name Beaver Full Moon come from the fact that the beavers are now active in their preparation for winter. Also called the Frosty Moon.

December 15, 11:15 a.m. EST --TheFull Cold Moon

Among some tribes, the Full Long Nights Moon. In this month the winter cold fastens its grip, and the nights are at their longest and darkest. Also sometimes called the Moon before Yule (Yule is Christmas, and this time the Moon is only just before it).

The term Long Night Moon is a doubly appropriate name because the midwinter night is indeed long and the Moon is above the horizon a long time. The midwinter full Moon takes a high trajectory across the sky because it is opposite to the low Sun.

© 2005 Space.com. All rights reserved. More from Space.com.

Source: http://www.msnbc.msn.com/id/7013393/

Astronews - January 2005

Caution: This moon is flammable

 

Saturn's largest moon apparently is lashed regularly by rain made of liquid methane, forming pools, cutting river beds and eroding rocks in much the same way that forces have shaped the Earth, scientists said Friday.

The European Space Agency's probe that landed on Titan's frozen surface a week ago put Europe's stamp on the distant reaches of the solar system with its discoveries of a mysterious, methane-rich globe.

"We've got a flammable world, and it's quite extraordinary," said Toby Owen, a scientist from Honolulu's Institute for Astronomy who was charged with studying the moon's atmosphere.

Black-and-white photos from the Huygens probe show a rugged terrain of ridges, peaks, dark vein-like channels and apparently dry lakebeds on the moon 744 million miles away.

On Earth, methane is a flammable gas. On Titan, it is a liquid because of the intense pressure and cold -- 274 degrees below zero.

"There is liquid that is flowing on the surface of Titan. It is not water -- it is much too cold -- it's liquid methane, and this methane really plays the same big role on Titan as water does on Earth," said mission manager Jean-Pierre Lebreton. "There are truly remarkable processes at work on Titan's surface and in the atmosphere of Titan which are very, very similar to those occurring on Earth."

A sensor about the size of a police officer's nightstick on the front of Huygens probed beneath the moon's crust and found a material with the consistency of loose sand.

Channels on the surface are evidence of methane rain. There are also what appear to be river systems and deltas, frozen protrusions riddled by channels, apparent dried-out pools where liquid has perhaps drained away, and stones -- probably ice pebbles -- that seem to have been rounded by erosion.



"Does it rain only once a year? Is there a wet season once a year? Does it rain more frequently? We don't know," said another member of the team, Martin Tomasko of the University of Arizona. "The feeling is that in the place we landed, it must rain fairly frequently, but we can't be more precise than that."

The area is "more like Arizona, or someplace like that, where the river beds are dry most of the time," he added. "Right after the rain, you might have open flowing liquids, then there are pools, the pools gradually dry out, the liquid sinks down into the surface. Perhaps it's very seasonal."

The river beds are darkened by what seem to be particles of smog that fall out of Titan's atmosphere, coating the terrain. The dirt apparently gets washed off the ridges by the methane rain to collect in the river channels.

It did not appear to be raining when Huygens descended through Titan's haze on parachutes, "but it has been raining not long ago," Lebreton said.

Scientists believe the dark smog particles are formed by Titan's methane, breaking up in the atmosphere. That raised another question: Where does the methane come from?

"There must be some source of methane inside Titan which is releasing the gas into the atmosphere. It has to be continually renewed, otherwise it would have all disappeared," Owen said.

But he also cautioned that they should not generalize too much from the area they surveyed about what the rest of Titan might look like.

Lebreton, the mission manager, said a next possible step in Titan exploration would be to send mobile probes, perhaps balloons to float around before landing.

The Mars Rover team has already contacted him to say that "they really now are dreaming of sending their rovers on the surface of Titan," he added. "This is highly possible -- that we can now dream seriously of sending rovers on the surface of Titan. We just need the money."

The probe was named after Titan's discoverer, the 17th-century Dutch astronomer Christiaan Huygens.

Huygens was spun off from the Cassini mother ship on Dec. 24. The $3.3 billion Cassini-Huygens mission to explore Saturn and its moons was launched in 1997 from Cape Canaveral, Fla., a joint effort between NASA, ESA and the Italian space agency.

Titan is the first moon other than the Earth's to be explored, and David Southwood, ESA's director of science programs, reflected Europe's pride in the accomplishment.

"Hello America, we're in the exploration business, too," Southwood told reporters.

European Space Agency: www.esa.int


URL: http://sfgate.com/cgi-bin/article.cgi?file=/news/archive/2005/01/21/international1517EST0581.DTL

 

Huygens probe lands on Titan on Friday

 

Huygens trajectory spot on


Huygens approaching Titan

Not the Death Star! A photo of the Huygens probe approaching Titan


12 January 2005

Early on Christmas Day 2004, the Cassini mothership flawlessly released ESA's Huygens probe. But how do we know that it is on the right course and how accurately can we tell?

Since Huygens has no propulsion system of its own, it had to be put on course for its descent before it was released.

As planned, a fine tuning of the Cassini trajectory took place on 22 December to place Huygens on its nominal entry trajectory.

While Huygens will remain on this trajectory until it plunges into Titan's atmosphere on 14 January, the Cassini orbiter performed a deflection manoeuvre on 28 December to avoid crashing onto the moon.

Huygens is scheduled to reach Titan's upper atmosphere at about 10:06 CET on 14 January, entering the atmosphere at a relatively steep angle of 65 degrees and a velocity of about six kilometres per second.

The fine-tuning manoeuvre, called 'Targeting Clean-up', was critical: if the entry angle is too steep, the probe could overheat and burn up in the atmosphere; if the angle is too shallow, the probe might skim like a pebble on the surface of a lake and miss its target.

After the probe's separation from Cassini, telemetry data were collected by NASA's Deep Space Network stations in Madrid, Spain, and Goldstone, California. From these data confirming the release, we know the speed after release, and that the probe is spinning as planned to keep stable. Images from Cassini's cameras showing the probe drifting away were taken on 25-27 October.

Although only a few pixels across, these images taken at different distances between the probe and the orbiter helped navigators to reconstruct the probe's trajectory. Using the backdrop of known stars, and pinpointing Huygens's position relative to Cassini, the probe's trajectory was reconstructed using radio and optical navigation techniques.

This information is important to help establish the required geometry between the probe and the orbiter for radio communications during the probe descent on 14 January. It also shows that the probe and Cassini are well within the predicted trajectory accuracy.

Jean-Pierre Lebreton, ESA's Huygens Mission Manager said: "We know now that Huygens is going to hit Titan's upper atmosphere with a high precision. We are using this latest information to update our Huygens trajectory prediction. However, we still can't say precisely where Huygens is going to impact on the surface as the touchdown longitude will be most influenced by the drift of the parachute caused by the wind. This may be as large as 300-400 kilometres eastwards."

Learn more at Huygens.com

Astronews - December 2004

Geminids Meteor Shower Peaks TONIGHT!

 

Disappointed with the meager showing put on by this year's Leonid meteor shower?

The best meteor display of the year is scheduled to reach its peak tonight, Monday night, Dec. 13, 2004

Skywatchers lucky enough to have dark skies and be far away from the glare of city lights could see one or two meteors every minute during the Geminid meteor shower.

The greatest activity is expected to be visible from North America, Europe and Africa.

The Geminids get their name from the constellation of Gemini, the Twins. On the night of this shower's maximum, the meteors will appear to emanate from a spot in the sky near the bright star Castor in Gemini.

The Geminid meteors are usually the most satisfying of all the annual showers, even surpassing the famous Perseids of August. Studies of past displays show that this shower has a reputation for being rich both in slow, bright, graceful meteors and fireballs as well as faint meteors, with relatively fewer objects of medium brightness.

This year, the Moon will be at New phase Dec. 11. On the peak night, the Moon will be a skinny crescent, low in the west-southwest at dusk and setting before 6 p.m. That means the sky will be dark and moonless for the balance of the night, making for perfect viewing conditions.

Generally speaking, depending on your location, Gemini begins to come up above the east-northeast horizon right around the time evening twilight is coming to an end. So you might catch sight of a few early Geminids as soon as the sky gets dark. There is a fair chance of perhaps catching sight of some "Earth-grazing" meteors.

The Geminids begin to appear noticeably more numerous in the hours after 10 p.m. local time Monday, because the shower's radiant is already fairly high in the eastern sky by then. The best views, however, come around 2 a.m. Tuesday, when their radiant point will be passing very nearly overhead. The higher a shower's radiant, the more meteors it produces all over the sky.

If you plan to stay up and stay outside in the cold, remember to wrap up much more warmly than you think is necessary!

Give your eyes 15 minutes or more to adapt to the darkness before getting serious about meteor watching. And have something comfortable to sit on; a lounge chair will allow you to stare up for long periods without straining your neck.

Geminids stand apart from the other meteor showers in that they seem to have been spawned not by a comet, but by 3200 Phaeton, an Earth-crossing asteroid. Then again, the Geminids may be comet debris after all, for some astronomers consider Phaeton to really be the dead nucleus of a burned-out comet that somehow got trapped into an unusually tight orbit.

Learn some more at Sky & Telescope:

The Geminids: An Exception to the Rule

Astronews - October 2004

Start drinking 7Up! Official beverage of Ansari X-Prize offering a free trip to space!

 

WHAT's the prize beneath the cap of that soft drink bottle? A trip into space.

It may sound far-fetched – if not a little crass – but the commercialisation of the final frontier began in earnest when a privately funded rocket, with a pilot and the weight equivalent of two passengers, soared into space for the second time in a week.

SpaceShipOne, adorned with sponsor's logos, twice easily eclipsed the previous flight-altitude record for an air-launched craft – 354,000 feet (107,900m) by the X-15 in 1963 – and so won a $US10 million ($13.84 million) Ansari X-Prize while also raising hopes for space tourism.

One of SpaceShipOne's sponsors and the "official beverage" of the AnsariX Prize, the soft drink 7Up, announced it would be offering the first free ticket into space.

Read the entire article here:
7Up tops off space flight with ticket to ride