Arecibo Observatory via CNN Giant asteroid flying by Earth next week looks like it's wearing a face mask

[Disir]

An asteroid estimated to be 1.2 miles wide will fly by Earth next week, but it's not expected to collide with our planet.

And if an asteroid could be aware of such things, it appears to be wearing a face mask in deference to the pandemic, according to new images from Arecibo Observatory in Puerto Rico.

The asteroid is called 52768 (1998 OR2), and it was first spotted in 1998.

On April 29, it will pass within 3,908,791 miles of Earth, moving at 19,461 miles per hour. That's still 16 times farther than the distance between Earth and the moon.

Giant asteroid flying by Earth next week looks like it's wearing a face mask

An asteroid estimated to be 1.2 miles wide will fly by Earth next week, but it's not expected to collide with our planet.

www.ksl.com

This is kind of cool.

 

[Admiral Rockwell Tory]

The Arecibo Observatory is a radio telescope. It cannot "see" shit!

 

[Likkmee]

Everyone pray it hit's capi.toll hill(while maintaining social distancing) and things will be better FAST.

 

[Pogo]

The Arecibo Observatory is a radio telescope. It cannot "see" shit!

Fer chrissake learn what a metaphor is.

 

[miketx]

An asteroid estimated to be 1.2 miles wide will fly by Earth next week, but it's not expected to collide with our planet.

And if an asteroid could be aware of such things, it appears to be wearing a face mask in deference to the pandemic, according to new images from Arecibo Observatory in Puerto Rico.

The asteroid is called 52768 (1998 OR2), and it was first spotted in 1998.

On April 29, it will pass within 3,908,791 miles of Earth, moving at 19,461 miles per hour. That's still 16 times farther than the distance between Earth and the moon.

Giant asteroid flying by Earth next week looks like it's wearing a face mask

An asteroid estimated to be 1.2 miles wide will fly by Earth next week, but it's not expected to collide with our planet.

www.ksl.com

This is kind of cool.

You don't think it wants to risk getting the china/democrat virus do you?

 

[luchitociencia]

The Arecibo Observatory is a radio telescope. It cannot "see" shit!

Consider yourself very lucky, because if you were able to see it with your naked eyes, then you and the rest of us might have a huge problem.

 

[fncceo]

People "see" what they want to see.

It's the 21st century and we've been to Mars but, people still believe Mars is covered by canals and has huge human-faced sculptures.

 

[Bob Blaylock]

The Arecibo Observatory is a radio telescope. It cannot "see" shit!

That was pretty much my first thought when I saw this thread title, was to wonder how a radio telescope would be able to see any detail on an object that surely is not a radio emitter.

I just checked the Wikipedia article about it, to see if, by chance, there might be any mention of there being any significant optical telescope also present at that site, and found no mention of any such telescope. I did, however, find mention of the Arecibo radio telescope being configured to transmit as well as receive, which opened, in my mind, the possibility that it might be able to view non-radio-emitting objects via an active radar method.

Only after all this did I actually look at the article linked in the OP, where I see that the image said to be from Arecibo is captioned, “This Doppler radar image…”, which seems to confirm this, as does mention in the text of the article about radar imaging. The asteroid is apparently being observed from Arecibo, not by any radio that it itself emitting, but by radio waves transmitted from Earth (probably by the Arecibo device itself, but possibly from another source) and being bounced off of it.

 

[Admiral Rockwell Tory]

The Arecibo Observatory is a radio telescope. It cannot "see" shit!

That was pretty much my first thought when I saw this thread title, was to wonder how a radio telescope would be able to see any detail on an object that surely is not a radio emitter.

I just checked the Wikipedia article about it, to see if, by chance, there might be any mention of there being any significant optical telescope also present at that site, and found no mention of any such telescope. I did, however, find mention of the Arecibo radio telescope being configured to transmit as well as receive, which opened, in my mind, the possibility that it might be able to view non-radio-emitting objects via an active radar method.

Only after all this did I actually look at the article linked in the OP, where I see that the image said to be from Arecibo is captioned, “This Doppler radar image…”, which seems to confirm this, as does mention in the text of the article about radar imaging. The asteroid is apparently being observed from Arecibo, not by any radio that it itself emitting, but by radio waves transmitted from Earth (probably by the Arecibo device itself, but possibly from another source) and being bounced off of it.

Sorry! It does not work like that. A Doppler radar, even if it could work at that range, calculates the frequency shift to determine relative velocity. It would still give you no idea of the size.

 

[Bob Blaylock]

Sorry! It does not work like that. A Doppler radar, even if it could work at that range, calculates the frequency shift to determine relative velocity. It would still give you no idea of the size.

It's possible that the use of the word “doppler” is incorrect,here,but nevertheless, the basic idea is sound.

What a radio telescope does is to image objects based on radio waves received from them, rather than light. I think it's usually a passive process, based on radio waves emitted from the object itself, or possibly bounced off of that object fro another source. In this case, it seems apparent, radio waves were specifically transmitted at the asteroid in question, so that the Arecibo telescope could image it based on radio waves reflected off of it. Most radar applications with which we are familiar do not involved forming detailed images, but then most radar applications don't involve a huge 1,000-foot-diameter, ƒ/0.435 dish and sensors specifically made to form images based on received radio signals.

 

[Admiral Rockwell Tory]

Sorry! It does not work like that. A Doppler radar, even if it could work at that range, calculates the frequency shift to determine relative velocity. It would still give you no idea of the size.

It's possible that the use of the word “doppler” is incorrect,here,but nevertheless, the basic idea is sound.

What a radio telescope does is to image objects based on radio waves received from them, rather than light. I think it's usually a passive process, based on radio waves emitted from the object itself, or possibly bounced off of that object fro another source. In this case, it seems apparent, radio waves were specifically transmitted at the asteroid in question, so that the Arecibo telescope could image it based on radio waves reflected off of it. Most radar applications with which we are familiar do not involved forming detailed images, but then most radar applications don't involve a huge 1,000-foot-diameter, ƒ/0.435 dish and sensors specifically made to form images based on received radio signals.

I was a radar technician in the Navy. You are oversimplifying the issue.

 

[Bob Blaylock]

I was a radar technician in the Navy. You are oversimplifying the issue.

Possibly true, to some extent. I understand the basic concept. Radar, in general, works by transmitting a radio signal, and detecting when that signal echos back from an object. There are probably some passive radar applications that work by detecting radio signals transmitted by an object. So far as I know, radar does not usually involve any kind of sophisticated imaging, to reveal details of an object, just timing and detection in order to detect the location, distance, and speed of an object.

What is at Arecibo is a huge, sophisticated imaging device. It work almost exactly like an optical telescope, but with radio waves instead of light. That's what it is designed to do, and that's what it does.

Until this discussion, I was only really aware of it as a passive device, that images very distant astronomical objects by the radio waves given off by those objects, just as an optical telescope images distant objects by the light given off by, or reflected off of those objects.

What I only learned today is that it also is capable of transmitting a powerful signal. An obvious application of this, which the OP's article seems to imply is relevant in this case, would be to transmit that signal at an object such as this asteroid, and then use the returning signal to image that asteroid; much like a flash unit on a camera.

As an amateur photographer, and an amateur astronomer, familiar with the optical principles involved in light-based photography and telescopy, (microscopy, too, that's another hobby of mine, but it's somewhat less relevant to this discussion than the other two), it is very obvious to me how these principle would be at work here.

I do not know what you think you know, as a radar technician, that would refute what I know as a photographer and telescopist, but as I am not aware of this sort of imaging being a thing that most common radars would do, it wouldn't surprise me if, as a radar technician, you might have no awareness of how the relevant principles would apply here.

 

[Wuwei]

I was a radar technician in the Navy. You are oversimplifying the issue.

Possibly true, to some extent. I understand the basic concept. Radar, in general, works by transmitting a radio signal, and detecting when that signal echos back from an object. There are probably some passive radar applications that work by detecting radio signals transmitted by an object. So far as I know, radar does not usually involve any kind of sophisticated imaging, to reveal details of an object, just timing and detection in order to detect the location, distance, and speed of an object.

What is at Arecibo is a huge, sophisticated imaging device. It work almost exactly like an optical telescope, but with radio waves instead of light. That's what it is designed to do, and that's what it does.

Until this discussion, I was only really aware of it as a passive device, that images very distant astronomical objects by the radio waves given off by those objects, just as an optical telescope images distant objects by the light given off by, or reflected off of those objects.

What I only learned today is that it also is capable of transmitting a powerful signal. An obvious application of this, which the OP's article seems to imply is relevant in this case, would be to transmit that signal at an object such as this asteroid, and then use the returning signal to image that asteroid; much like a flash unit on a camera.

As an amateur photographer, and an amateur astronomer, familiar with the optical principles involved in light-based photography and telescopy, (microscopy, too, that's another hobby of mine, but it's somewhat less relevant to this discussion than the other two), it is very obvious to me how these principle would be at work here.

I do not know what you think you know, as a radar technician, that would refute what I know as a photographer and telescopist, but as I am not aware of this sort of imaging being a thing that most common radars would do, it wouldn't surprise me if, as a radar technician, you might have no awareness of how the relevant principles would apply here.

You are correct. This site gives some good resolution pictures of Venus and Mercury using the Arecibo Observatory. It imaged the surface structure of the planets by timing echos sent from the observatory with "delay-Doppler coordinates." There are interesting pictures.

Planetary Radar at Arecibo Observatory

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