3D Orbit Simulation: http://neo.jpl.nasa.gov/cgi-bin/db?name=2002+NY40
> http://science.nasa.gov/headlines/y2002/30jul_ny40.htm > > Look at that Asteroid > NASA Space Science > > A big space rock will soon come so close to Earth that sky watchers > can see it through binoculars. > > July 30, 2002: Relax, there's no danger of a collision, but it will be > close enough to see through binoculars: a big space rock, not far from > Earth. > > Astronomers discovered the nearby asteroid, named 2002 NY40--not to be > confused with better-known 2002 NT7--on July 14th. It measures about > 800 meters across, and follows an orbit that ranges from the asteroid > belt to the inner solar system. On August 18th, the asteroid will > glide past our planet only 1.3 times farther away than the Moon. > > "Flybys like this happen every 50 years or so," says Don Yeomans, the > manager of NASA's Near-Earth Object Program office at JPL. The last > time (that we know of) was August 31, 1925, when another 800-meter > asteroid passed by just outside the Moon's orbit. In those days there > were no dedicated asteroid hunters--the object, 2001 CU11, wasn't > discovered until 77 years later. At the time of the flyby, no one even > knew it was happening. > > 2002 NY40 is different. We know the asteroid is coming, and > astronomers have time to prepare. > > One team of observers led by Mike Nolan at the giant Arecibo radar in > Puerto Rico will "ping" 2002 NY40 with radio waves as it approaches > Earth. Such data result in impressive 3D maps of asteroids, which have > often surprised astronomers with their weird shapes. Some prove to be > binary systems (one space rock orbiting another) and one even looks > like a dog bone. > > "Radar data will also improve our knowledge of the asteroid's orbit," > adds Jon Giorgini, a member of the radar team from JPL. "At present, > we know there's little risk of a collision with 2002 NY40 for decades. > When the Arecibo radar measurements are done, the orbit uncertainties > should shrink by more than a factor of 200. We'll be able to > extrapolate the asteroid's motion hundreds of years into the past and > into the future, too." > > 2002 NY40 is faint now. It shines by reflected sunlight like a 17th > magnitude star. As it nears Earth, however, the space rock will > brighten, soaring to 9th magnitude on August 18th. That's about 16 > times dimmer than the dimmest star you can see without a telescope. > But as asteroids go, it's very bright. > > "Asteroids are hard to see," explains Yeomans, "because they're mostly > black like charcoal. The most common ones--carbon-rich C-type > asteroids--reflect only 3% to 5% of the light that hits them. Metallic > asteroids, which are somewhat rare, reflect more: 10% to 15%." > > "We don't know yet what this asteroid is made of," he continued, "but > we'll have a much better idea by the end of August." Astronomers using > ground-based telescopes will have little trouble recording the > asteroid's spectrum and thus its composition. > > On the date of closest approach, the asteroid will sail past Vega, the > brightest star in the evening summer sky. Sky watchers with powerful > binoculars or small telescopes can see it--a speck of light moving 8 > degrees per hour. (Note: The flyby will be visible mostly from Earth's > northern hemisphere; this is not a good opportunity for southern sky > watchers. North Americans can see it best after sunset on Aug. 17th; > Europeans should look during the hours before dawn on Aug. 18th.) > > Something extraordinary will happen hours after 2002 NY40 passes > Earth: the space rock will quickly fade. > > Asteroids, like moons and planets, have phases. The sunlit side of > 2002 NY40 is facing Earth now. It's full, like a full Moon. On August > 18th, the asteroid will cross Earth's orbit on its way toward the Sun. > Then the phase of the asteroid will change--from full to gibbous to > half.... finally the night side will turn to face Earth. The asteroid > will grow dark, like a new Moon. > > It's not every day you can peer through binoculars and see a > near-Earth asteroid--and then see it disappear. But 2002 NY40 has a > lot to offer. > > "Mother Nature is making it very easy for us to study this one," says > Yeomans. That's good because "we need to know more about near-Earth > asteroids in case we ever need to destroy or deflect one." What are > they made of? How are asteroids put together? These are key questions > that 2002 NY40 will help answer. > > "Don't forget," adds Yeomans, "most asteroids pose no threat to Earth. > But they do contain valuable metals, minerals and even water that we > might tap in the future." When such asteroids come close (but not too > close!) we have relatively easy access to them--both to study and, one > day perhaps, to visit. > > Or, to paraphrase Nietzsche, asteroids (like 2002 NY40) that do not > hit us, make us stronger. > > For more information about 2002 NY40, including an up-to-date > ephemeris for sky watchers, please visit JPL's Near-Earth Object > Program web site: > > http://neo.jpl.nasa.gov > > 3D Orbit Simulation: http://neo.jpl.nasa.gov/cgi-bin/db?name=2002+NY40 > -- THE END ==^================================================================ This email was sent to: archive@jab.org EASY UNSUBSCRIBE click here: http://topica.com/u/?bUrHhl.bVKZIr Or send an email to: [EMAIL PROTECTED] T O P I C A -- Register now to manage your mail! http://www.topica.com/partner/tag02/register ==^================================================================
