APOD: Perseid Below (2011 Aug 17)

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APOD: Perseid Below (2011 Aug 17)

Post by APOD Robot » Wed Aug 17, 2011 4:09 am

Image Perseid Below

Explanation: Denizens of planet Earth watched this year's Perseid meteor shower by looking up into the moonlit night sky. But this remarkable view captured by astronaut Ron Garan looks down on a Perseid meteor. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow. Out of the frame, the Sun is on the horizon beyond one of the station's solar panel arrays at the upper right. Seen above the meteor near the horizon is bright star Arcturus and a star field that includes the constellations Bootes and Corona Borealis. The image was recorded on August 13 while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing.

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Re: APOD: Perseid Below (2011 Aug 17)

Post by geckzilla » Wed Aug 17, 2011 4:09 am

I wonder if Chris's camera managed to capture the same Perseid?
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Re: APOD: Perseid Below (2011 Aug 17)

Post by neufer » Wed Aug 17, 2011 4:15 am

geckzilla wrote:
I wonder if Chris's camera managed to capture the same Perseid?
"The image was recorded while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing. "
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Re: APOD: Perseid Below (2011 Aug 17)

Post by Beyond » Wed Aug 17, 2011 4:23 am

geckzilla wrote:I wonder if Chris's camera managed to capture the same Perseid?
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Re: APOD: Perseid Below (2011 Aug 17)

Post by bystander » Wed Aug 17, 2011 4:31 am

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Re: APOD: Perseid Below (2011 Aug 17)

Post by bactame » Wed Aug 17, 2011 4:58 am

The APOD indicates the space station is NW of Beijing by 400 km? Doesn't it look like the viewpoint of the camera is SW of the city; the sun is rising in the NE and the meteor is heading south while the bright collection of lights on the ground is north of the camera. Neat image though and the bulge of ionization trails the meteor when viewed at full resolution.

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Re: APOD: Perseid Below (2011 Aug 17)

Post by kaigun » Wed Aug 17, 2011 5:24 am

I don't want to be morbid, but what would happen if one these dust grains traveling at 60 kilometers per second was to strike the space station? Even if the mass is small, that's a lot of velocity.

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Re: APOD: Perseid Below (2011 Aug 17)

Post by alter-ego » Wed Aug 17, 2011 5:25 am

bactame wrote:The APOD indicates the space station is NW of Beijing by 400 km? Doesn't it look like the viewpoint of the camera is SW of the city; the sun is rising in the NE and the meteor is heading south while the bright collection of lights on the ground is north of the camera. Neat image though and the bulge of ionization trails the meteor when viewed at full resolution.
The view is to the NW looking out over Mongolia and Russia.
Perseid Cities from ISS.JPG
Last edited by alter-ego on Wed Aug 17, 2011 5:49 am, edited 1 time in total.
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Re: APOD: Perseid Below (2011 Aug 17)

Post by alter-ego » Wed Aug 17, 2011 5:36 am

kaigun wrote:I don't want to be morbid, but what would happen if one these dust grains traveling at 60 kilometers per second was to strike the space station? Even if the mass is small, that's a lot of velocity.
Micro-meteorite impacts are not uncommon. The do leave dings in spacecraft (e.g. Shuttle), but fortunately not typically big enough to kill one or even do serious damage. I don't know the size threshold for meteor to punch a hole in the ISS. If I'm not mistaken, the Hubble takes protective measures by pointing away from the radiant and/or closing the "lid" during meteor showers.

You may find this interesting: http://www.nasa.gov/centers/wstf/labora ... /mmod.html
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Re: APOD: Perseid Below (2011 Aug 17)

Post by bystander » Wed Aug 17, 2011 6:10 am

http://asterisk.apod.com/viewtopic.php? ... 70#p155325
kaigun wrote:I don't want to be morbid, but what would happen if one these dust grains traveling at 60 kilometers per second was to strike the space station? Even if the mass is small, that's a lot of velocity.
alter-ego wrote:Micro-meteorite impacts are not uncommon. The do leave dings in spacecraft (e.g. Shuttle), but fortunately not typically big enough to kill one or even do serious damage. I don't know the size threshold for meteor to punch a hole in the ISS. If I'm not mistaken, the Hubble takes protective measures by pointing away from the radiant and/or closing the "lid" during meteor showers.

You may find this interesting: http://www.nasa.gov/centers/wstf/labora ... /mmod.html
See also discussion in APOD: Castle and Meteor by Moonlight (2011 Aug 13), starting here.
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Re: APOD: Perseid Below (2011 Aug 17)

Post by Indigo_Sunrise » Wed Aug 17, 2011 10:42 am

What a fortuitous image!
Interesting that the 'shooting stars' look pretty much the same from space.


*And alter-ego, you never cease to amaze with your interpretive mapping of so many of the images - Thanks!


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Re: APOD: Perseid Below (2011 Aug 17)

Post by saturn2 » Wed Aug 17, 2011 12:26 pm

Perseid meteor.
The view of Earth from ISS is very good.
The speed of meteor is 60 kilometers per second.
The spacecraft New Horizont has only a speed of 17 kilometers per second.
60 km/s it´s a big speed.
Will can a spacecraft to go 60 Km/s in the future?

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Re: APOD: Perseid Below (2011 Aug 17)

Post by neufer » Wed Aug 17, 2011 12:58 pm

saturn2 wrote:
The speed of meteor is 60 kilometers per second.

The spacecraft New Horizons has only a speed of 17 kilometers per second.
60 km/s it´s a big speed.
Will can a spacecraft to go 60 Km/s in the future?
Only by traveling close to the Sun or Jupiter.
http://en.wikipedia.org/wiki/Helios_probes wrote:
<<Helios-A and Helios-B (also known as Helios 1 and Helios 2), were a pair of probes launched into heliocentric orbit for the purpose of studying solar processes. A joint venture of the Federal Republic of Germany (West Germany) and NASA, the probes were launched from the John F. Kennedy Space Center at Cape Canaveral, Florida, on Dec. 10, 1974, and Jan. 15, 1976, respectively. The probes are notable for having set a maximum speed record among spacecraft at 70.22 km/s or 0.000234c. Helios 2 flew three million kilometers closer to the Sun than Helios 1, achieving perihelion on 17 April 1976 at a record distance of 0.29 AU, slightly inside the orbit of Mercury. Helios 2 was sent into orbit 13 months after the launch of Helios 1. The Helios space probes completed their primary missions by the early 1980s, but they continued to send data up to 1985. The probes are no longer functional but still remain in their elliptical orbit around the Sun.>>
http://www.daviddarling.info/encyclopedia/F/fastest_spacecraft.html wrote:

<<The record for the fastest spacecraft of all is held by the twin Helios probes that were placed in orbit around the Sun. Both these vehicles reached top speeds of around 70 km/s at closest approach to the Sun in their highly elliptical orbits, Helios 2 being marginally the swifter.

The highest speed for any atmospheric entry was achieved by the Galileo spacecraft when it plunged to its intentional destruction in the atmosphere of Jupiter at 48.3 km/s, narrowly beating the previous record of 47.2 km/s achieved by its own atmospheric probe, eight years earlier. The highest speed at which a spacecraft has entered Earth's atmosphere 13 km/s in the case of Stardust, comfortably surpassing the 11 km/s reentry speed of the Apollo 10 Command Module and its three-astronaut crew.

The highest speed at which any spacecraft has ever escaped from the Earth is 16 km/s in the case of the New Horizons probe, which was launched in January 2006 and is now heading toward Pluto. This beats the 15.4 km/s Earth escape speed of the solar probe Ulysses, launched in 1990 and the 14.5 km/s Earth escape speed of the Jupiter probe Pioneer 10, launched in 1972.

New Horizons is unlikely, however, to claim a second record, as the fastest interstellar spacecraft ever launched from Earth. After its encounter with Pluto and possibly one or more objects in the Kuiper Belt, New Horizons will leave the Solar System, to join four other spacecraft – Voyager 1 and Voyager 2, and Pioneer 10 and Pioneer 11 – that are also on exit trajectories from the Sun's realm. Currently, of this group, Voyager 1 is traveling the fastest away from the Sun with a speed of 17.3 km/s. New Horizons will approach Pluto with a speed of about 14 km/s and it is unlikely that this will be boosted beyond the speed of Voyager 1 by the relatively weak gravitational effect of Pluto or other small bodies in the Kuiper Belt.>>
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Re: APOD: Perseid Below (2011 Aug 17)

Post by orin stepanek » Wed Aug 17, 2011 1:05 pm

Too bad there was a full moon during the peak of the meteor shower! :?
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17/8-11 APD: meteor/ISS p.o.v.

Post by Doc Cherokee » Wed Aug 17, 2011 1:55 pm

Spent a rainy Friday nite in Tulsa, watching many great sites and listening to the the sounds of stars falling thanks to NASA/Air Force et al. Will look up sites and report later. Went out the 14th/4-6am (CST), and saw 1 large and 2 small, at TU campus.
But todays APD was the icing on the cake.

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Re: APOD: Perseid Below (2011 Aug 17)

Post by mtbdudex » Wed Aug 17, 2011 1:57 pm

This is a cool APOD, hits home - would be neat if someone ground wise had captured the same streak!

For me I was outside 3:30am - 5:30am August 12, 2011, trying to capture Perseid's as the moon was low/setting and before the sun rose.
Managed to capture 5, they are "hidden" in this 1.5 hour startrails composite.
URL shows 800pix
https://lh5.googleusercontent.com/-pkJs ... e-dark.jpg
Image

Bonus, ISS also captured, it's the middle white 6 streaks between the 2 red airplane streaks.
Image Image

The ISS was over me 3:53 am on the 12th, while the closest Perseid I captured timewise was the one below at 4:03am
These is a crop, about 1600 pix wide, hosted at 800pix wide and posted here 400 pix wide
(original image is 4752 pix wide)
#1 date/time 2011:08:12 04:03:38 am, this took PP in CS5 to bring out the streak while toning down the moon light.
URL shows 800pix:
https://lh6.googleusercontent.com/-vSSp ... 525202.jpg
Image

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Re: APOD: Perseid Below (2011 Aug 17)

Post by geckzilla » Wed Aug 17, 2011 2:43 pm

neufer wrote:
geckzilla wrote:
I wonder if Chris's camera managed to capture the same Perseid?
"The image was recorded while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing. "
Reading fail. :oops:
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Re: APOD: Perseid Below (2011 Aug 17)

Post by kaigun » Wed Aug 17, 2011 2:47 pm

Alter-ego-

Thanks for the interesting link. That explained a lot.

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Post by neufer » Wed Aug 17, 2011 3:07 pm

http://www.universetoday.com/88180/meteors-sound-like-aliens/ wrote:
<<A space radar picked up the sounds of a meteor shower as it delighted skywatchers over the weekend.

What do meteors sounds like as they hit Earth’s atmosphere? From this recording made by the U.S. Air Force Space Surveillance Radar in Texas, the “pings” from the Perseid Meteor Shower sound rather alien! The radar station in Lake Kickapoo, Texas is part of United States Strategic Command’s (USSTRATCOM), which involves detecting, tracking, cataloging and identifying artificial objects orbiting Earth, such as both active and inactive satellites, spent rocket bodies, or fragments of debris from natural and man-made objects. Reportedly, the radar can detect objects as small as 10 cm at heights up to 30,000 km.>>
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Re: APOD: Perseid Below (2011 Aug 17)

Post by Wolf Kotenberg » Wed Aug 17, 2011 9:39 pm

I my memory serves me correctly, last years Perseids were recorded as flashes on the moons surface, seven of them as i recall.

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Re: APOD: Perseid Below (2011 Aug 17)

Post by RSteff » Wed Aug 17, 2011 10:39 pm

Is the green upper-atmosphereic glow that we're viweing tangentially in the center of the image, airglow?

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Re: APOD: Perseid Below (2011 Aug 17)

Post by neufer » Wed Aug 17, 2011 11:15 pm

RSteff wrote:
Is the green upper-atmosphereic glow that we're viweing tangentially in the center of the image, airglow?
"the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow."
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Re: APOD: Perseid Below (2011 Aug 17)

Post by neufer » Wed Aug 17, 2011 11:29 pm

Wolf Kotenberg wrote:
If my memory serves me correctly, last years Perseids were recorded as flashes on the moons surface, seven of them as i recall.
http://www.lunarimpacts.com/lunarimpacts.htm
http://science.nasa.gov/science-news/science-at-nasa/2008/02sep_lunarperseids/ wrote: Amateur Astronomers See Perseids Hit the Moon
There's more than one way to watch a meteor shower.
Sept. 2, 2008: Dr. Tony Phillips | Credit: Science@NASA

<<One, the old-fashioned way: Find a dark place with starry skies and count the meteors streaking overhead. Two, the new way: Find a dark place with starry skies and then completely ignorethe meteors. Instead, watch the Moon. That's where the explosions are.

On August 9th, a pair of amateur astronomers on opposite sides of the United States did it the new way. With the Perseid meteor shower just underway, they fixed their cameras on the Moon and watched meteoroids slam into the lunar surface. Silent explosions equivalent to ~100 lbs of TNT produced flashes of light visible a quarter of a million miles away on Earth. It was a good night for "lunar Perseids."

"I love watching meteor showers this way," says George Varros, who recorded this impact from his home in Mt. Airy, Maryland:

The flash, which lit up a nighttime patch of Mare Nubium (the Sea of Clouds), was a bit dimmer than 7th magnitude--"an easy target for my 8-inch telescope and low-light digital video camera."

Hours later, another Perseid struck, on the western shore of Oceanus Procellarum (the Ocean of Storms). This time it was Robert Spellman of Azusa, California, who caught the flash. "It's exciting to witness these explosions in real time," he says. "I used a 10-inch telescope and an off-the-shelf Supercircuits video camera."

Rob Suggs of NASA's Meteoroid Environment Office has reviewed the data. "They look real to me," he says. "The flashes appear in multiple video frames and the light curves are similar to other lunar meteors we've recorded in the past."

Suggs would know. Along with colleague Bill Cooke, he leads a team at the Marshall Space Flight Center that has recorded more than 100 lunar explosions since 2005. "We monitor lunar meteors in support of NASA's return to the Moon," Suggs says. "The Moon has no atmosphere to protect the surface, so meteoroids crash right into the ground. Our program aims to measure how often that happens and answer the question, what are the risks to astronauts?"

NASA's official lunar meteor observatories are located in Alabama and Georgia. Both were off-line on August 9th, so the NASA team didn't see how many Perseids were hitting the Moon that night.

"This shows how amateur astronomers can contribute to our research," points out Suggs. "We can't observe the Moon 24-7 from our corner of the USA. Clouds, sunlight, the phase of the Moon—all these factors limit our opportunities. A global network of amateur astronomers monitoring the Moon could, however, approach full coverage."

By day, George Varros is a software engineer at NASA headquarters. After work, he takes off his NASA badge, goes home and fires up his self-described "barely adequate" telescope. "Until a few years ago, I really didn't like the Moon because it interfered with my observations of comets and meteors. Then, in 1999 during the Leonid meteor storm, (fellow amateur astronomer) David Dunham photographed six lunar impact events from my backyard in Maryland," Varros recalls. "I was hooked."

Dunham's observations inspired not only Varros, but also NASA. "Our own observing program can be traced back to those early amateur observations of lunar Leonids," says Suggs.

A major advance in lunar meteor detection came in 2006 in the form of LunarScan, a computer program written by amateur astronomer Pete Gural that searches digital video of the Moon for split-second flashes. Using LunarScan, Varros has bagged at least a dozen lunar meteors. Three of them were observed simultaneously by the NASA team in Alabama, confirming the fidelity of Varros' techniques. (LunarScan may be freely downloaded from Varros' web site; NASA uses the program, too!)

Like Varros, Robert Spellman's interest in lunar meteors began with the Leonids of 1999. "I read about the success of amateurs recording impact flashes," he recalls. "I've been in love with the Moon since my first observation when I was five years old, and I wanted to conduct an observing program with scientific value. Lunar meteors were a natural." Spellman's day job is at the Natural History Museum of Los Angeles and the La Brea tar pits where he works as an educator. He also conducts public astronomy programs three nights a week at the Griffith Observatory. The rest of his evenings he devotes to the Moon. Spellman uses no special software to catch his impacts. "I look for the flashes in real time," he says. "Although it may sound tedious to stare at a blank screen for hours on end, the prospect of seeing an explosion keeps me alert. In future, I do plan to use LunarScan to increase my success rate."

Suggs hopes other amateurs will take up this hobby, not only to improve NASA's lunar impact statistics, but also to support the agency's LCROSS mission: In 2009, the Lunar CRater Observation and Sensing Satellite (LCROSS) will intentionally dive into the Moon, producing a flash akin to a natural lunar meteor. Unlike natural meteoroids, which hit the Moon in random locations, LCROSS will carefully target a polar crater containing suspected deposits of frozen water. If all goes as planned, the impact will launch debris high above the lunar surface where astronomers can search the ejecta for signs of H2O. The impact flash (if not hidden by crater walls) and the debris plume may be visible to backyard telescopes on Earth.

Ready for meteor watching--the new way? NASA offers a FAQ and telescope tips to help you get started. Good hunting!>>
Art Neuendorffer

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Re: APOD: Perseid Below (2011 Aug 17)

Post by Beyond » Thu Aug 18, 2011 1:13 am

geckzilla wrote:
neufer wrote:
geckzilla wrote:
I wonder if Chris's camera managed to capture the same Perseid?
"The image was recorded while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing. "
Reading fail. :oops:
Don't be concerned about it geckzilla. A few eye drops in the Oculars and you'll be Digitatoring good as new :!: :shock:
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Re: APOD: Perseid Below (2011 Aug 17)

Post by saturn2 » Thu Aug 18, 2011 1:23 am

Neufer
Thanks by your explanation.
The speed of spacecrafts is very important.

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