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[Chicago Astronomer - Astro Joe]

Small Asteroid Passes Between Satellites and Earth

Seems like we missed another close encounter with space debris. The Following from Space.com:

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Astronomers spotted an asteroid this week after it had flown past Earth on a course that took it so close to the planet it was below the orbits of some satellites.

The space rock was relatively small, however, and would not have posed any danger had it plunged into the atmosphere.

The object, named 2004 YD5, was about 16 feet (5 meters) wide, though that's a rough estimate based on its distance and assumed reflectivity. Had it entered the atmosphere, it would have exploded high up, experts figure.

Satellite territory

The asteroid passed just under the orbits of geostationary satellites, which at 22,300 miles (36,000 kilometers) altitude are the highest manmade objects circling Earth. Most other satellites, along with the International Space Station, circle the planet at just a few hundred miles up.

2004 YD5 is the second closest pass of an asteroid ever observed by telescope, according to the Asteroid/Comet Connection, a web site that monitors space rock discoveries. The closest involved a rock that flew by last March and was not announced until August.

2004 YD5 was discovered Tuesday, Dec. 21 by Stan Pope, who volunteers his time to examine images provided by the FMO (Fast Moving Object) project, an online program run by the University of Arizona's Spacewatch Project. After the initial detection, other observers noted the object's position during the day and its path was then calculated back. Closest approach occurred on Dec. 19.

The rock approached Earth from near the Sun and so would have been nearly impossible to detect prior to close passage. It soared over Antarctica -- underneath the planet, Washington State University researcher Pasquale Tricarico told the Asteroid/Comet Connection.

Astronomers are aware of this significant blind spot for asteroids that approach Earth while in the glare of the Sun. Only a space telescope could detect such objects before they arrive.

More Here: www.space.com/scienceastronomy/asteroid_close_041222.html

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Perhaps the recent fireballs observed on the Asian contentant are related to this astroid.

I have many hard hats no farther than 5 paces at any given time!

[dewayne]

Stan Pope lives in Morton, IL., about 12 miles from me.
I talked to him briefly yesterday over the phone.
I'm going to meet with him this week for an interview.
I'm going to put together a story on him.
I[ll post it here when I get done.

[Chicago Astronomer - Astro Joe]

DeWayne,

The interview will be a great read, I look forward to it.

There are many unknown rocks heading our way!

[stanpope]

dewayne said:

Stan Pope lives in Morton, IL., about 12 miles from me.
I talked to him briefly yesterday over the phone.
I'm going to meet with him this week for an interview.
I'm going to put together a story on him.
I[ll post it here when I get done.

Well, DeWayne did the interview (several exchanges of emails ... I think he ran out of questions before I ran out of emailed answers) and the article has been published. He did a nice job, and his knowledge of astronomy did show through ... no gaffs! I think that DeWayne has since moved on to another job, and may no longer be able to reprint the story legally.)

I put my personal account of the experience on my website at members.aol.com/standcmr/fmo.htm. I'm still rather new at the formal process of astronomy, but have been an avid reader of all aspects of the physical sciences for about 50 years. I suspect that being listed in an MPEC is as close as I'll ever get to Harvard U.

[Chicago Astronomer - Astro Joe]

Stan,

Thank you for joining the Chicago Astronomer family and for your first post.

When I first heard of this asteroid I was amazed. So close and under several satellites! And now having it's discoverer amongst us is quite cool as well!

Tell us some more of this, info that usually gets edited out. How did you get started?

I think that one is going to hit us, without any warning whats so ever! I have my hard hat at the ready!

[stanpope]

Thank you, Joe.

Here's some details, most of which did not show up in any of the articles ...

Spacewatch is an organized effort concerned with NEO's (Hard hat sized and above.) The FMO Project is a part of Spacewatch and runs out of Steward Observatory, SW of Tucson, AZ. The onsite staff produces a survey of up to about 960 reviewed images per night, depending on seeing conditions. Part of the project plan is to augment professional astronomers by enlisting the aid of interested volunteers to perform the review. Each image is about 1 MBytes jpeg and an 1200X900 screen will see about 1/4 of an image at a time.

The survey consists of three series of images taken at about 30 minute intervals. The middle series is put on a queue for review by volunteers in bunches of about 160. Those volunteers who are logged in at the time pull an image for review, mark "suspicious" locations, and return the image for another. The volunteer's second phase is to review the detailed pic of the locations he marked. This review consists of looking at small "blink imges" (animated gif's) made up from each of the three series of images. An FMO will show only in the middle image. Stars will be fixed "points" and FMO's will be trails around 3/8" long with the apparent width of approx. 19th magnitude stars. The volunteer makes his final decision on whether to submit or not from these blink images. He "weeds out" the pics of edge-on galaxies, trails left by "cosmic rays", trails left by artificial satellites, etc.

Review is performed at near real-time, and all images are typically reviewed within a few 10's of minutes of release. So, participation has the same kind of time schedule as typical field astronomy. (The internet does cause a "time shift", since volunteers in Australia, Hawaii or Netherlands are in different parts of their "day" than volunteers in Arizona or Illinois. Illinois volunteers typically need to be active during the 10pm to 7 am time. But, not necessarily for the entire period!)

It is important that images be reviewed promptly, since they will soon be beyond viewable distance. A little one like mine was rapidly becoming fainter, and would probably have been lost had recoveries not been accomplished on 21 or 22 December.

The onsite astronomer(s) manage the survey process on a 0.9m scope and also perform recoveries of FMO's using a separate (1.8m?) scope. They also check on submissions from the volunteers and make the final decision regarding submission to MPC (Minor Planet Center) for dissemination to others who will hopefully provide enough observations to define the orbit accurately.

I first heard of the project about a year ago, but set it aside because I had slow internet service (56Kbs) and downloading 1 MB images would be cumbersome in a "real time" activity. I did go through the "online instruction" sequence at the time and decided it looked interesting enough to look at again later.

In the fall, I got broadband service (cable TV related) and renewed my interest in the FMO Project in November, just in time for the "Full moon shutdown" (the 9 days that bracket the full moon.)

Over the course of December, I reviewed a total of about 45 images. The 29th image was a good one! Since then, I've reviewed another 200 images with no hits. (Just a couple of suspicious cosmic ray trails.) Typically, the project discovers about 10 to 15 FMO's per year, which gives some idea of just how infrequent the FMO's show up in the images. If the averages hold, I'll review another few thousand images before discovering another FMO!

[TheCriticalEye]

A bus sized asteroid burns up in the earths atmosphere about once a month. Would be cool to see a killer fireball run across the sky !

[Chicago Astronomer - Astro Joe]

It certainly would be cool.

I have viewed a couple of clips, one in film and the other in video, of a huge fireball shooting thru our atmosphere and heading back out into space. Quite a remarkable capture!