Talk about getting nothing done....I started in earnest to visit you all but couldn't get my mind out of space, thinking about Asteroid 2007WD5 and whether it'll hit Mars or not. The odds keep getting better each day and it's almost Wednesday so time will certainly tell a tale. If you've forgotten about it, click into the left pane there, "ODDS OF COLLISION..." post, that seems to be the most up-to-date. Think of it: A mile-long, 400-feet wide, this returning rock will come into Martian space at 8.5 miles per second around 5:56 a.m. EST. Hope it hits, we'll gain so much science from it.
But for earth? We're not left out. We've an Asteroid coming our way too - this ones' called 2007TU24 and it's less than 2 million miles from earth at this moment. TU24 is 800 feet wide and headed straight toward us. Don't start sounding the apocalyptic horn, we've plenty of radar up there plotting every move. It's closest approach will be on the 29th, this Tuesday, at 8:33 UT or 3:33 a.m. EST. Distance from earth will be a very comforting 340,000 miles, or 1.44 times the mean distance of the moon. So fear not. This is strickly a telescopic event. But don't you want to see it fly past if you can?
On the night of closest approach, this Monday-Tuesday, it's magnitude will be bright enough for all Americas to see easily with binocs. How brilliant it'll be depends on the curve of sunlight hitting it. TU24's peak will be about 8 hours after its closest approach, and even as it fades into space it'll still be quite visible. The speed of travel past earth is approximately 7 times faster than the moon, which is half the speed that surrounding "fixed" stars drift across the sky (due to the rotation of earth).
But you really shouldn't be surprised to hear all the commotion made about "last days" and "prepare now" warnings. I have to think such persons don't know how many millions of objects hit this planet in just my lifetime (57 years). Which brings to mind another object falling to earth: A satellite which has left its orbit is headed into our atmosphere. It'll mostly burn up on approach but little pieces will fall here and there,like metal golf-balls on fire. This happens all the time and people don't really know or care and that's okay too, but remember the piece that hit someone's car and incinerated it? Just a reminder of the power of gravity here. I love gravity.
NOW I'll get to those Journals..... :-)
Basics courtesy of JPL, S&T, Gryphon, Goldtsone RT, star charts.