People in the eastern United States will get a great opportunity, weather permitting, to see the Space Shuttle Discovery launched into orbit Wednesday evening, March 11.

The Shuttle flight (STS-119) will be the 28th to rendezvous and dock with the International Space Station (ISS) and the glow of its engines will be visible along much of the Eastern seaboard of the United States.

To reach the ISS, Discovery must be launched when Earth's rotation carries the launch pad into the plane of the ISS's orbit. For mission STS-119, on March 11 that will happen at 9:20:10 p.m. ET, resulting in NASA's first Shuttle flight of 2009 and its second consecutive nighttime (the previous shuttle flight, last November 14, was also a nighttime launch). This launch will bring the Shuttle's path nearly parallel to the U.S. East Coast.

What to expect

For most locations, Discovery will be visible by virtue of the light emanating from its three main engines. It should appear as a very bright, pulsating, fast-moving star, shining with a yellowish-orange glow.

Based on previous night missions, the brightness should be at least equal to magnitude -2; somewhat brighter than Sirius, the brightest star in the sky, which shines brilliantly in the south-southwest during the evening hours. Observers who train binoculars on the Shuttle should be able to see the rapidly moving shuttle resembling a tiny V-shaped contrail.

In the Southeast United States, depending on a viewer's distance from Cape Canaveral, Discovery will become visible anywhere from a few seconds to 2 minutes after it leaves Pad 39-A. The brilliant light emitted by the two solid rocket boosters will be visible for the first 2 minutes and 4 seconds of the launch out to a radius of some 520 statute miles from the Kennedy Space Center.

No matter where you're located, keep in mind that the Shuttle will not get very high above the horizon. In most cases, it will range from roughly 5 to 10 degrees. To get an idea of how high this is, make a fist and hold it out at arm's length. Place the bottom of your fist on the horizon; the top of your fist is 10 degrees

By location:

Southeast U.S. coastline:

Anywhere north of Cape Canaveral, I suggest viewers initially concentrate on the south-southwest horizon (if you are south of the Cape, look low toward the north-northeast).

Mid-Atlantic region:

Look toward the south about 3 to 6 minutes after launch.

Northeast (Washington, Philadelphia, New York, Boston):

Concentrate your gaze low toward the south or south-southeast about 6 to 8 minutes after launch. Of course, as the shuttle gets closer, its azimuth very quickly swings over to the southeast, where in most cases, the point of maximum altitude occurs. I suspect most people will be scanning the horizon from south-southeast in the final couple of minutes of powered ascent . . . if so, you shouldn't miss out on sighting Discovery.

Discovery will seem to flicker, then abruptly wink-out 8 minutes and 23 seconds after launch as the main engines shut-down and the huge, orange, external tank is jettisoned over the Atlantic at a point about 870 statute miles uprange (to the northeast) of Cape Canaveral and some 430 statute miles southeast of New York City. At that moment, Discovery will have risen to an altitude of 341,600 feet (64.7 statute miles), while moving at more than 17,000 mph and should be visible for a radius of about 770 statute miles from the point of Main Engine Cut Off, or MECO.

Should the launch of Discovery be scrubbed on Wednesday, March 11, the launch will be rescheduled on a daily basis, but the time of the launch will occur roughly 23 minutes earlier for each day the launch is delayed (launch window times through March 16).

Before hoping to see the Shuttle streak across your local sky, make sure it has left the launch pad! Watch a television news outlet to verify that Discovery has been launched, or you can watch the launch on your computer via streaming video from NASA-TV.

Good Luck!

To date it has been a superb winter for viewing the queen of the planets, Venus.  February marks the pinnacle of its evening visibility as it stands like a sequined showgirl nearly halfway up in the western sky at sunset. Currently shining at its greatest brilliance for this apparition, this dazzling evening star appears as a distinct crescent shape in small telescopes, which is growing progressively larger in size as it approaches our Earth.

And be sure to get out your calendar and put a big circle around Friday, February 27, 2009, for that evening a lovely crescent Moon will appear to snuggle up close to Venus, particularly for skywatchers across the Western Hemisphere.  It will make for an eye-catching scene as the two brightest sky objects of the night dominate the early evening scene for about three hours after sundown; even those who do not normally look up will likely have their attention drawn to this dynamic duo during their normal commute home from work or school.  What will make this array especially attractive is the fact that it will look almost three-dimensional; the Moon will look almost like an eerily illuminated blue and yellow Christmas ball hovering next to the brilliant-white diamond that is Venus.

Sadly, this will be the last in the current series of evening get-togethers between the Moon and Venus, for during March Venus will slide rapidly down into the sunset glow and by month's end will disappear from our evening sky until the spring of 2010.

But again . . . Friday night, February 27 will be the night when the Americas will be greeted with one of the most beautiful Venus-crescent Moon conjunctions possible. The pairing will persist from before sunset on into the depths of darkness.  The time when Moon and planet will appear closest will be around 8:30 p.m. Eastern time (7:30 p.m. Central, 6:30 p.m. Mountain, and 5:30 p.m. Pacific).  Venus will appear to hover approximately 1.5-degrees above and to the right of the 10-percent illuminated Moon (the Moon itself appears one-half degree in diameter).  For cities situated in the Mountain time zone, the time of closest approach will come during evening twilight, while for those in the Pacific time zone it takes place around, or just prior to sunset.

From other places around the world, the pairing will appear a bit different primarily because the Moon appears to move much more rapidly against the background stars than Venus, and also because of the effect of parallax: different viewing angles from different points on our planet.

From Europe, for instance, Venus will appear to hover majestically about 4-degrees directly above the Moon at sunset.  South Americans will see the Moon with Venus to its right; the pair low in the west-northwest at dusk and appearing to set side-by-side.  From Australia, the Moon will be positioned far to the lower left of Venus on the evening of Feb. 27 and a somewhat similar distance to its upper right the following evening.

Finally, if you're watching with some friends, here's a trivia question you might want to pose to them: Of the two which do they believe is the brighter: Venus now at its peak brilliance or the three-day old Moon?  The almanacs say that the Moon is 8.5 times (2.3 magnitudes) brighter, but because its light is not concentrated into a point like Venus, they may have a difficult time believing this!

The telescope technique of adaptive optics is rapidly advancing, allowing unprecedented ground-based views of distant galaxies, stars, and planets both inside and outside our Solar System. Adaptive optics reduces the greatest obstacle to a clear picture for telescopes viewing the sky from Earth: interference from our own planet’s atmosphere.

Astronomers with the European Southern Observatory recently used adaptive optics to spot details in the core of NGC 253, one of the brightest and dustiest spiral galaxies in the sky. The new image shows that the core is packed with massive nurseries of young stars. The observations also suggest that the supermassive black hole at this galaxy’s center is similar to the one at the center of the Milky Way. Learning more details about our galactic neighbors allows researchers to better understand how our own galaxy compares to the crowd.

To learn about other recent astronomical discoveries, visit the Science Bulletins website.