View Full Version : How to see the comet crash tonight!!

Thomas W Tanner--
07-03-2005, 12:41 PM

How to See NASA’s Comet Crash in the Sky Tonight
LAST UPDATE: 7/3/2005 12:04:08 PM
Posted By: Selena Garza
This story is available on your cell phone at mobile.woai.com.

By J. Kelly Beatty, Executive Editor of Sky & Telescope

When NASA's Deep Impact slams an 800-pound projectile into Comet Tempel 1 at 23,000 miles per hour, the collision should create quite a splash. Cameras and other instruments on the main spacecraft will watch this first-ever comet excavation from a safe distance, and astronomers on Earth will be looking on with powerful mountaintop telescopes.

Here's a handy list to track Deep Impact's progress on the web:

NASA webcast of live mission coverage.
The Kitt Peak National Observatory in Tucson, Arizona is providing a live webcast of the collision beginning about an hour before the comet collision.
In Bathurst, Australia, astronomers with the Charles Stuart University's Remote Telescope will broadcast live Deep Impact observations from sunset to midnight local time.
Atop Hawaii's Mauna Kea, the W.M. Keck Observatory will post near-real time images of Deep Impact's Tempel 1 crash as seen through a Celestron 11-inch CGE telescope.
The Dyer Observatory at Vanderbilt University in Nashville, Tennessee will begin a live stream of its Deep Impact observations just before the collision. Vanderbilt physicist Robert O'Dell, a former chief scientist for the Hubble Space Telescope, will provide commentary.
In Sonora, Mexico, the Carl Sagan Observatory will offer a live webcast in Spanish, and also contains some feature video on comets and the Deep Impact mission.
Countless amateur stargazers will be watching too. If you have a telescope or binoculars, you can watch to see if the comet brightens after the probe's kamikaze plunge. Contrary to optimistic predictions, you're unlikely to see anything of this event with your unaided eye. But you can at least see the place in the sky where it's happening.

Your location will be important. The crash is set to happen at 12:52am tonight (early in the morning on July 4th). At that moment, the comet will be well placed in a dark sky from the western United States, especially the Southwest. But for much of the eastern United States and Canada the comet will have already slipped below the horizon.

"Anyone west of the Mississippi River has a chance of seeing the comet when Deep Impact slams into it," says Kelly Beatty, executive editor of SKY & TELESCOPE magazine. "People in Southwestern Canada, Mexico, and Central America will have good seats too."

Here's where to look. After dark, find Jupiter shining high in the southwest. It's the brightest "star" in that part of the sky (brighter Venus sets in the west-northwest during dusk). Off to Jupiter's left, by somewhat more than the width of your fist seen at arm's length, is the fainter star Spica. The impact with the comet will happen a couple of finger-widths above Spica.

Even during and after impact the comet is expected to remain faint, and telescope users will need to use the detailed star chart that accompanies this release. Suitable charts also appear in the June 2005 issue of SKY & TELESCOPE, the July-August 2005 issue of NIGHT SKY, and online at SkyandTelescope.com. Anyone who's not already familiar with how to use star charts with a telescope will need to follow the beginner's instructions in the online article.

Some scientists speculate that Comet Tempel 1 will stay bright long after it gets hit, so you may be able to spot it for several nights after July 3rd. If your evening sky is clear on July 6th or 7th, there's an easy way to find Comet Tempel 1 with your telescope. Just center Spica in your lowest-power eyepiece, then let the sky drift by (turn off the scope's tracking motor if it has one). Wait exactly 20 minutes, and Comet Tempel 1 should be in the field of view.

Much more about the Deep Impact mission and its target comet appears in the cover stories of the June 2005 SKY & TELESCOPE.

In The Sky
Bob Kelley, Scobee Planetarium

July Sun – Although you wouldn’t know it by looking at the sizzling summer temperatures, believe it or not, the days are actually growing shorter! As we move further away from June 21st - the summer solstice and the longest day of the year - the amount of time our star actually spends above the horizon decreases ever so slightly. For example, on July 1st, the sun rises at 6:39am, sets at 8:37pm, and spends 13 hours and 58 minutes in the sky. By July 31st, the Sun rises at 6:55am, sets at 8:26pm, and is above our horizon for 13 hours and 31 minutes – a decrease of 27 minutes of possible sunshine. Also, the angle of the Sun’s maximum height above the southern horizon at “solar noon” drops from 83 and 1/3 degrees at the beginning of the month, to 78 and 1/3 degrees at month’s end. This slight drop in the sun’s maximum height is not much now, but it heralds the eventual shift from summer towards the fall. Two other items of interest also involve the Sun. July 2nd marks the midpoint of the year. 2005 is half complete! Three days later on July 5th, the Earth is at its farthest point from the Sun. Know as aphelion, our planet reaches its maximum distance from the Sun of about 94.5 million miles. Our star begins the month of July in the constellation of Gemini, but gradually moves eastward along the ecliptic into the stars of Cancer by month’s end.

July Moon – Our lunar companion begins the month of July as a thin crescent in the predawn sky. Sky gazers rising at 5:00am on July 2nd will be treated to a nice view of the crescent Moon alongside the Pleiades star cluster above the eastern horizon. The Moon reaches New phase and passes between the Earth and the Sun on July 6th. Returning to the evening sky, a very thin crescent Moon hovers just above the planets Venus and Mercury on July 8th. Look for this pairing of the Moon and the two innermost planets low in the northwest following sunset on July 8th. Moving eastward along the ecliptic, the Moon appears alongside the bright planet Jupiter on July 12th and 13th. First Quarter Moon occurs the next night on July 14th. On the night of July 17th, the Moon “occults” or covers the star Antares, the brightest in the constellation of Scorpius the Scorpion. Antares is hidden behind the Moon for about 40 minutes starting near 11:10pm.

Full Moon arrives on July 21st. July’s full phase is known as the “Hay Moon” or “Thunder Moon”. Moving into the late night hours, the Last Quarter Moon and the planet Mars rise together prior to sunrise on July 27th.

July Planets - The two innermost worlds of the Solar System, Mercury and Venus, remain near one another in the evening skies during the first week of July. A lovely clustering of the thin crescent Moon, Venus and Mercury takes place after sunset on July 8th. Saturn is visible far to lower right of both Venus and Mercury during the first evenings of July, but the ringed planet soon is lost in the sunset glare. Saturn reaches conjunction with the Sun on July 23rd. After this date, Saturn moves into the morning sky, but will not return into view until late August. Likewise, Mercury follows Saturn into the Sun’s glow and disappears into the solar glow by midmonth.

Giant Jupiter is easily glimpsed in the evening skies high above the southwestern horizon amidst the stars of Virgo. Gleaming a brilliant white in color, Jupiter shares the celestial stage with the Moon on both nights of July 12th and 13th. Notice the apparent distance between the planets Venus and Jupiter. Although they appear far apart in July, by the end of August, Jupiter and Venus will pass each another in the evening sky! A pair of binoculars will show you Jupiter’s four largest moons.

Mars, the orange-red planet, rises above the eastern horizon around 2:00am. Rapidly brightening and gradually increasing in telescopic size, Mars continues moving towards its next close passage with the Earth which occurs in late October and early November this fall. Look for the Moon and Mars together prior to sunrise on July 27th

Deverne Girdler
07-03-2005, 07:28 PM
we can only guess that there is a real reason for shooting at it,

nobody says what the real reson is.


Thomas W Tanner--
07-03-2005, 09:17 PM
we can only guess that there is a real reason for shooting at it,

nobody says what the real reson is.


From what I've read, comets are the aftermath of the creation of the universe ("Big Bang"). We are probing this comet to learn what we may about the "Big Bang Theory".


Mark Conte -
07-04-2005, 10:42 AM
To find out if it can be stopped in the future if one of its kind heads to earth.

Flora Porter
07-04-2005, 03:44 PM
From what I've read, comets are the aftermath of the creation of the universe ("Big Bang"). We are probing this comet to learn what we may about the "Big Bang Theory".

Hi Tom,

Thanks for posting this imporant event. ;)