astronomy & space stuff

Pulling them from the SpaceWeather.com gallary. Thought I'd toss a couple here for those of us too far south to see them in person until the next X20 comes towards us.
 
SRC: http://www.cnn.com/2004/TECH/11/16/scramjet.delay/index.html

Experimental NASA jet reaches Mach 10
Final test of X-45A appears to go as planned

From Kate Tobin
CNN

Tuesday, November 16, 2004 Posted: 10:09 PM EST (0309 GMT)

(CNN) -- The National Aeronautics and Space Administration conducted a third and final test flight of the unmanned X-43A aircraft, which uses an experimental scramjet engine designed to push the craft to nearly 10 times the speed of sound.

A scramjet differs from conventional jet technology by not using rotor blades to compress the air inside the engine. Instead, the scramjet, sometimes called an "air-breathing" engine, burns hydrogen fuel in a stream of fast-moving, compressed air created by the forward motion of the aircraft.

Hot exhaust shooting out of the back of the jet propels it forward at high speed.

At a post-flight news conference Tuesday, mission managers said they had only begun to look at the data, but they believed the aircraft reached a speed of about 6,600 miles (10,621 kilometers) per hour, or about Mach 10.

The flight took place over the Pacific Ocean off the coast of Southern California, in restricted U.S. Naval airspace.

The black X-43A, fastened to a larger, white booster rocket, was carried to 40,000 feet (13,157 meters) strapped to the right wing of a B-52, which took off from NASA's Dryden Flight Research Center in Edwards, California.

The B-52 released the booster rocket, which dropped for several seconds with the X-43A attached to its nose, then ignited and ascended to 110,000 feet (36,184 meters). At that point, the scramjet engine fired and the booster rocket dropped away.

As planned, the test flight lasted only a couple of minutes and ended when the aircraft ran out of fuel. It eventually crashed harmlessly into the ocean.

The test flight was originally scheduled for Monday, but technical glitches forced NASA to postpone it for 24 hours.

Tuesday's flight was the last of three test flights in NASA's eight-year, $230 million Hyper-X program, designed to help develop a new generation of spacecraft that could fly into low Earth orbit at a fraction of the current cost.

Some engineers have even speculated that scramjets could one day power a fleet of hypersonic airplanes, capable of crossing a continent in less than an hour. The technology also has military applications, with the potential for new innovations in ballistic missiles.

Scramjet technology could eliminate the need to use heavy liquid oxygen to launch spacecraft and rockets into orbit. A speed of Mach 25, or 17,000 miles (27,200 kilometers) per hour, is needed to lift a craft into orbit.

In 2001, the X-43A's maiden flight ended unsuccessfully after an onboard booster rocket misfired and flight controllers had to destroy the aircraft. But last March, its second flight was successful, reaching almost Mach 7.

However, with NASA now dedicating the bulk of its resources to returning the space shuttle fleet to flight, completing construction of the international space station and developing technology for manned missions to the Moon and Mars, no additional scramjet flights are on the drawing board.
 
AURORA WATCH: Earth will glide through a solar wind stream on Nov. 19th or 20th, possibly sparking a geomagnetic storm at high latitudes. Sky watchers in, e.g., Alaska and Canada should be alert for auroras.
 
THE LEONIDS: The 2004 Leonid meteor shower peaks on Friday, Nov. 19th. Sky watchers in Europe and Asia are favored; they could see as many as 60 meteors per hour when Earth skims through a cloud of comet dust at 2149 GMT (4:49 p.m. EST).

In the Americas, meteor rates will be lower, perhaps only 5 to 15 per hour--nothing like the jaw-dropping displays of recent years. The best time to look will be during the hours just before local dawn on Friday, Nov. 19th, and Saturday, Nov. 20th.

You can also listen to the shower. The USAF Space Surveillance Radar (formerly NAVSPASUR) is monitoring the skies above the southern United States. Whenever a Leonid meteor streaks overhead, it records a ghostly ping (sample).
Click to listen:
live! NAVSPASUR audio stream


Live audio from NAVSPASUR is provided by amateur astronomer Stan Nelson of Roswell, New Mexico. He also operates a 67 MHz forward-scatter meteor radar; you can listen to that, too.
 
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METEOR UPDATE: Compared to the storms of recent years, last week's Leonid meteor shower was a dud. Good news: another much better shower is coming. The 2004 Geminid meteor shower is due to peak on Dec. 13th. The moon will be almost-new and skies will be dark, revealing dozens to hundreds of bright meteors.

http://www.spaceweather.com/
 
LUNAR OCCULTATION: Mark your calendar. On Tuesday, Dec. 7th, about an hour before sunrise, the crescent Moon will eclipse Jupiter. Astronomers call this a "lunar occultation." You can see it if you live in the eastern two-thirds of North America. When the time comes, go outside and look southeast: sky map.
 
GIANT FILAMENT: There's a dark gash across the sun today. It's a solar filament: a relatively cool and dense ribbon of gas held together by solar magnetic fields. Greg Piepol of Rockville MD photographed it, along with the rest of the sun, on Nov. 26th:

http://www.spaceweather.com/swpod2004/29nov04/Piepol1.jpg
There are several filaments in Piepol's photo; most are small. The big one, the eye-catching "gash," spans more than 250,000 miles, about the same as the distance between Earth and the Moon.
 
http://science.msfc.nasa.gov/headlines/y2004/images/geminids2004/Westlake1_med.jpg

The Geminid Meteor Shower

The best meteor shower of 2004 peaks on Dec. 13th.

December 6, 2004: Make hot cocoa. Bundle up. Tell your friends: the best meteor shower of 2004 is about to peak on a long cold December night.

It's the Geminids. The best time to look is Monday night, Dec. 13th. Sky watchers who stay outside for a few hours around midnight can expect to see dozens to hundreds of "shooting stars."

The source of the shower is asteroid 3200 Phaethon. There's a cloud of dust trailing the asteroid and Earth plows through it every year in mid-December. Bits of dust traveling 80,000 mph hit our atmosphere and turn into glowing meteors.

Where should you look? Anywhere. Geminids streak all over the sky. Trace some backwards: they all lead to a radiant point in the constellation Gemini. This year the radiant lies next to Saturn--a beautiful coincidence. Gemini and Saturn are high overhead at midnight, easy to find.

(Take a look at Saturn using a telescope; you won't be disappointed. Even a small 'scope shows Saturn's breathtaking rings. You might also notice a pinprick of light near Saturn: that's Titan, Saturn's largest moon. Titan is an exquisitely weird place. It has orange clouds, an icy continent the size of Australia and, possibly, seas filled with something like gasoline. The ESA Huygens probe, to be deployed from NASA's Cassini spacecraft later this month, will land on Titan in January 2005.)

City lights are bad for meteor showers. The glare can reduce the number of meteors you see 3- to 10-fold. Consider taking a trip to the countryside. Because the Moon is almost new on Dec. 13th, country skies are going to be very dark and perfect for meteor watching.

Although the middle of the night is (probably) best, start looking for Geminids as soon as the sun goes down. The first dark hours after sunset are when Earthgrazers appear.

Earthgrazers are meteors that skim almost horizontally across the top of Earth's atmosphere, like a stone skipping across a pond. You might see a few between 5:00 p.m. and 7:00 p.m. local time when Gemini is first peeking over the eastern horizon (the perfect geometry for earthgrazing). Earthgrazers are bright, long and colorful. Even one can make your day.

Finally, the Geminids are a little strange. It's their parentage: 3200 Phaethon. Meteor showers are supposed to come from comets, but 3200 Phaethon looks like an asteroid. This has puzzled astronomers for years.

Comets are made of ice and dust and rock. Sunlight vaporizes the ice, opening fissures which spew gas and dust into space. This is why comets have tails. When Earth runs into an old comet tail we see a meteor shower. Asteroids, on the other hand, are mainly rocky and they rarely spew anything. No tail means no shower.

Asteroid 3200 Phaethon might have gotten a tail, of sorts, by bumping into another asteroid. 3200 Phaethon spends much of its time in the asteroid belt. Hitting a neighbor could have created a cloud of debris that follows 3200 Phaethon around the solar system.

That's one idea. Another is that 3200 Phaethon is a comet--a dead one. It died from too much Sun. Every year and a half, 3200 Phaethon dives inward from the asteroid belt. Passing only 2 million miles from Earth's orbit, it approaches the Sun closer than Mercury does. Repeated sunbaking could have vaporized all of 3200 Phaethon's ice long ago, leaving behind a rocky skeleton with a dribble of comet dust in its wake.

Comet? Asteroid? Comet-carcass? No one knows for sure. It's a mystery to savor on Dec. 13th … with hot cocoa at your side and the Geminids overhead.
 
COMET MACHHOLZ: Comet Machholz (C/2004 Q2) has been nearing Earth for weeks and now it's bright enough to see with the unaided eye. The comet looks like a fuzzy 5th-magnitude star near the feet of Orion. Look for it in the southeastern sky a few hours after sunset.

This comet is climbing higher in the sky and brightening a bit every night. Astronomers expect it to reach peak brightness (3rd or 4th magnitude) in January 2005--an easy target for Christmas telescopes.

http://www.spaceweather.com/comets/machholz/03dec04/holloway1_strip.jpg

http://www.spaceweather.com/images2004/13dec04/skymap_north.gif
 
Code:
Object    RA         DEC         ALT         AZ          Distance 
------------------------------------------------------------------
Mercury   16h 33.8m  -19° 19.5'   31° 45.7'  218° 39.7'   0.932070
Venus     21h 22.4m  -17° 38.7'   31°  0.7'  136° 55.9'   0.840414
Sun       18h  6.6m  -23° 25.8'   36° 53.6'  192° 41.9'   0.982637
Mars      12h 40.8m   -2°  1.3'   -3° 10.7'  269° 25.7'   1.497051
Jupiter    9h 19.0m   16° 34.9'  -32° 20.5'  316° 52.9'   4.574666
Saturn    18h 50.4m  -22° 11.1'   39° 12.9'  180°  8.4'  11.146374
Uranus     7h 24.3m   22° 23.0'  -38° 23.0'  350°  7.2'  17.641813
Neptune    8h 37.2m   18° 19.5'  -36° 29.6'  328°  4.9'  29.227718
Pluto      1h 38.9m   -8° 12.3'  -14° 26.2'   91° 34.5'  47.625509

RA - right ascension (hour angle)
DEC - declination (degrees)
ALT - altitude
AZ - azimuth
Distance - distance to the planet from Earth in AUs

http://home.att.net/~srschmitt/script_planet_orbits.html
 
Date: Sat, 11 Dec 2004 15:25:28 -0600
From: SpaceWeather.com <swlist@spaceweather.com>
To: SpaceWeather.com <swlist@spaceweather.com>
Subject: The Geminid Meteor Shower

Space Weather News for December 11, 2004
http://spaceweather.com

GEMINID METEORS: The 2004 Geminid meteor shower is underway. Midnight sky watchers this weekend can expect to see bright meteors shooting out of the constellation Geminid--at least a few per hour. Rates will increase many-fold on Dec. 13th when the shower peaks.

Because this meteor shower has such a broad peak, a good display is possible twice: on Monday morning, Dec. 13th, during the dark hours before sunrise and again on Monday evening, Dec. 13th, especially during the hours around midnight.

Visit spaceweather.com for more information and predictions for selected US cities.

COMET MACHHOLZ: While you're out watching the meteor shower, take a look at Comet Machholz--a 5th-magnitude fuzzball near the feet of Orion. You can see it with the unaided eye from dark-sky sites and it looks great through a small telescope.
 
src

Mars rover rises from crater for new trek
After studying Endurance Crater, Opportunity sets its sights for heat shield impact site and beyond
By James Oberg
NBC News space analyst
Special to MSNBC
Updated: 6:01 p.m. ET Dec. 13, 2004


After six months of exploring the inside of a stadium-sized Martian crater, the seemingly never-ending story of NASA's Opportunity rover continues with a trek across the Martian plains. New goals and new discoveries are already in sight.

Photographs released on Sunday show new views of the Martian plains, taken by the robot as it cleared the rim. One of the latest images shows a white object, the goal of Opportunity's next traverse.

This artificial structure is not some alien monument, but the probe’s own heat shield, released moments before its landing almost a year ago. Scientists are eager to examine both the shield and the deep hole it gouged into the ground.

How it got this far
Opportunity landed on Mars on Jan. 24, bouncing across Meridiani Planum and coming to rest within a 20-meter-wide (65-foot-wide) crater. Designed for a 90-day primary mission, the rover rolled across a cratered plain, examining rocks and small craters.

On June 10, long after its 90-day "warranty" had lapsed, Opportunity stood on the edge of a crater whose walls were lined with sedimentary rocks that promised to contain secrets of the early eons of Mars. After weighing the risks and potential payoffs, scientists sent the wheeled robot over the edge and into the crater.

Over the months that followed, Opportunity defied the depths of the Martian winter, a communications gap when Mars passed behind the sun, the minor aches and pains of aging hardware, and a growing burden of choking dust that slowly strangled the flow of electrical power from its solar energy panels. It drilled holes, sampled rocks and dust, and sent back pictures ranging from microscopic-scale detail shots to stunning panoramas.

Controllers at NASA's Jet Propulsion Laboratory faced steep, slippery slopes and crumbly soil where the six wheels turned as uselessly as auto wheels spinning in snow and ice. Planners also had to keep the rover’s top edged to the north to maximize the sunlight falling on the solar panels.

“The rover was pushed to its traverse limits, but continued to perform all that was asked of it,” mission planners said in a recent status report. “Opportunity remains in excellent health,” they said, adding that “solar power is nearly as high now as it was at the beginning of the mission.” Somehow the dust was not accumulating as fast as hoped, or was being shaken off by the rover’s frantic motions.

The crashed flying saucer
The rover mission's principal investigator, Steven Squyres of Cornell University, described the team’s plans in a recent interview with Astrobiology magazine.

”We've got a lot of things ahead of us,” he explained. “The first thing we're going to do is get to the heat shield. We've been itching to go to this thing for months now.”

The disk-shaped shield hit the ground at about 200 miles per hour. “It's going to look like a crashed flying saucer out in the desert,” Squyres joked.

”We want to look down into whatever hole it dug,” he said. “It's probably deeper than any hole that we can dig with our wheels.

Examining the shield itself will also help design future Mars probes, he added. This is important, he explained, because “no one's ever been able to examine a heat shield that's gone through the Martian atmosphere.” The rover will use its microscope to document the effects of the heat shield's fiery passage through the atmosphere — and the data could help designers craft thinner, lighter, more efficient shielding.

Squyres estimated that the heat shield was about 500 feet (150 meters) away.

Over the horizon
A few specific local science experiments will also now be possible. “There are a few cobbles — little fist-sized rocks scattered about the plains — and we've never looked at one,” Squyres told Astrobiology magazine. “So we're going to find out what those rocks are made of.”

The probe will then roll south, probably for the rest of its life. About a mile and a half (2.5 kilometers) away begins a region of what is called “etched terrain,” broad striped regions that are thought to represent different levels of sediments. Analyzing those layers could provide further insights about Mars' geological history.

About 2 miles (3.2 kilometers) even farther away is Victoria Crater, six times bigger than Endurance Crater. That may prove to be “one crater too far” — unreachable in any reasonable rover lifetime. But Opportunity and its twin rover Spirit, on the other side of the planet, already have shown surprising endurance, and there may be more surprises yet to come.
 
linuxgeek said:
COMET MACHHOLZ: Comet Machholz (C/2004 Q2) has been nearing Earth for weeks and now it's bright enough to see with the unaided eye. The comet looks like a fuzzy 5th-magnitude star near the feet of Orion. Look for it in the southeastern sky a few hours after sunset.

This comet is climbing higher in the sky and brightening a bit every night. Astronomers expect it to reach peak brightness (3rd or 4th magnitude) in January 2005--an easy target for Christmas telescopes.

http://www.spaceweather.com/comets/machholz/03dec04/holloway1_strip.jpg

http://www.spaceweather.com/images2004/13dec04/skymap_north.gif

i was looking at that night before last
:)
 
SOLAR ACTIVITY: There are no big spots on the sun today, but that doesn't mean solar activity is low. Astronomers are monitoring some impressive prominences churning over the sun's eastern limb. This 2-hour video, captured on Dec. 15th, comes from Didier Favre of Los Angeles, CA. The blue dot in the upper left corner is the size of Earth!
http://www.spaceweather.com/swpod2004/16dec04/favre1_med2.gif
 
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