SharpCap Forums

I really wanted to post an Animated GIF, but I just couldn't get the size down enough without sacrificing a lot.

This will have to suffice:
https://rumble.com/veimzt-near-earth-ob ... speed.html

I got the idea from an article posted yesterday at SpaceWeather.com. The topic was Asteroid Apophis which just whizzed by Earth. I kept reading, and then I read that it would be visible to the naked eye on April 13th. I said "whoa" I got to check that out. Well, it turned out the article referred to its next fly-by in 2029 when it comes within 25,000 miles of the Earth. Anyhow, I searched for Apophis, and found some recent posts at Stargazers Lounge. Someone mentioned a site called NEODyS-2. I visited it and discovered that I can conveniently search their database for other Near Earth asteroids that are visible from my backyard. I found 16th magnitude asteroid 2000EE14 in Hercules, but I had to wait until 2am for the show to start.

I prepared by doing some tests to see what kind of exposure I needed to clearly show a 16th magnitude star in a single frame. I decided upon 90 seconds at Bin 2. When the time came for the asteroid, I quickly realized that the asteroid was barely visible! What gives? The problem was that it was moving at an incredible rate of 7.3 arc-seconds per minute. That meant that in a 90-second exposure it had moved 11 arc-seconds! At Bin 2 my super pixel size is 4.6 arcsec by 4.6 arcsec. So, its photons were spread over 2 to 3 super-pixels. I had no choice but to switch to Bin 3 and reduce exposure to 60 seconds. That did the trick, but as usual the proper solution is to buy a larger aperture scope.

Here is a link to NEODyS-2 for the asteroid and time and place that I captured it:
https://newton.spacedys.com/neodys/inde ... f=53&yf=40

Brian

Hi Brian,

a great write up of a great imaging idea - thanks for sharing!

Robin

Again..really interesting Brian and another good video with nice music.

worked out - possibly incorrectly - that the apparent velocity is about 35,200 mph and the real speed greater than that depending on the direction of the vector relative to the earth. So in 2029 at only 25 000 miles away Apophis might be visible but could whip across the sky in only 3h or so? But here of course I am assuming that Apophis is moving at a speed similar to your asteroid -- which is doubtless wrong

thanks
TimH

Tim,

Using NEODyS website, I fast-forwarded to 2029. Here is what you can expect if you are at the Greenwich Observatory, England:

Time: April 13, 2029 21:30 UTC
Apparent motion: 2774 arcsec/minute
Earth distance: 0.002 AU
Sun elevation: -21 deg
Apparent magnitude: 3.34

That should be a great show! Dark skies. Motion: 0.77 deg/minute! Right smack in the middle of Cancer. Within the same FOV as Delta Cancri, magnitude 4.2. Unfortunately the Sun will still be up for me in New York.

Brian