Close approach asteroid

[Karls48 (Karl)]

The near-Earth asteroid, which is called 2005 YU55, will make its closest approach at 6:28 p.m. EDT (2228 GMT) on Nov. 8.
It is quite large - around 400m
(from Space.com)

[ZeroID (Brent)]

Mmm, 4:30 pm NZ time, can someone turn off that bright light in the sky for a couple of hours and I'll take a look see....

[Rob_K]

Originally Posted by ZeroID

Mmm, 4:30 pm NZ time, can someone turn off that bright light in the sky for a couple of hours and I'll take a look see....

And later on in the evening of the 9th there'll be that other bright light, a big fat gibbous Moon! After twilight 2005 YU55 will only be about 20-deg from the Moon viewed from my place, and will close in on it over the evening. Still 'bright' in the high mag 11s, but pretty difficult to view/capture. Info from JPL Small-Body Database Browser:
http://ssd.jpl.nasa.gov/sbdb.cgi#top

Put "2005 YU55" in the Search box, hit enter, click on "Ephemeris", then input your observer location and a time span.

Cheers -

[Tommy Camp]

Damn, at around 4 PM WA time, not much to see.

Originally Posted by ZeroID

Mmm, 4:30 pm NZ time, can someone turn off that bright light in the sky for a couple of hours and I'll take a look see....

If it's 6:30 EDT isn't it 8:30 or so NZ time?

[Allan_L (Allan)]

Originally Posted by Karls48

The near-Earth asteroid, which is called 2005 YU55, will make its closest approach at 6:28 p.m. EDT (2228 GMT) on Nov. 8.
It is quite large - around 400m
(from Space.com)

Am I missing something?
How does GMT 2228 equate to 6:28pm EDT.
Or Is EDT a US time zone?
I thought Sydney is AEDT.

In my calculations, 2228 GMT Nov 8, equals 9:28 AM AEDT on the 9th November.
Please someone correct me.

[Karls48 (Karl)]

EDT is US time zone. Closest approach will be Nov 8 22.28 GMT

[Rob_K]

As far as I can see, closest approach will be 23:28, 8 Nov UT. Immaterial really because it's approaching Earth from the sunward side and will not be optically visible from anywhere on Earth at that time. It will start to become visible a few hours after the close approach as it enters 'dark skies'. It will be brightest at mag 11.1 at around 4:30 9 Nov UT, or 3:30pm AEDST (UT+11), again in daylight for us. This is worked out on the phase versus the distance from us, and doesn't coincide with closest approach.

So the optimum time will be after twilight on 9 Nov. It will be about 20-deg away from the big gibbous Moon then, and will close in on it as the night progresses. It will be gradually fading, from mid mag 11s to around mag 12. The next night it will have faded right off into the mag 14s so there will only be one realistic opportunity, on the night of Wed 9 November in Australia. And a poor one because of the Moon.

I only have one query - the JPL ephemeris shows an 'instantaneous jump' from RA 23h to RA 00h at around 07:55 UT on the 9th. What's going on?

Cheers -

[Robh (Rob)]

Originally Posted by Rob_K

I only have one query - the JPL ephemeris shows an 'instantaneous jump' from RA 23h to RA 00h at around 07:55 UT on the 9th. What's going on?

Cheers -

RA 24h = RA 00h i.e. you're back to the origin of RA

Regards, Rob

[Rob_K]

Originally Posted by Robh

RA 24h = RA 00h i.e. you're back to the origin of RA

Regards, Rob

Ahh, duh-uh, thanks Rob (embarrassed!!).

Cheers -