Sky watchers in the Tri-State Area may get a look at an odd artificial cloud on Saturday night (Sep. 19) after it’s released from the fourth stage of a rocket set for launch from NASA’s Wallops Flight Facility on Virginia’s Atlantic Shore.

The cloud of aluminum particles from the rocket’s exhaust is expected to provide scientists with insights into the physics of “noctilucent clouds,” the highest natural clouds (around 50 miles up) that form in the Earth’s atmosphere.

The experiment, called “Charged Aerosol Release Experiment” (CARE), is being conducted by the Naval Research Laboratory and the Pentagon’s Space Test Program. Also involved are NASA, the University of Michigan, the Air Force Research Laboratory, Clemson, Stanford and Penn State universities, the University of Colorado and MIT.

The launch window for the experiment opens at 7:32 p.m. Saturday, and closes at 7:49 p.m. Weather forecasters gave the launch a 90 percent chance of favorable weather. However, clear skies are also needed up and down the coast to provide multiple camera locations with a view of the cloud.

Sunday, September 20, is the backup date for the launch. After that, the next opportunity would come next month.

The experiment is being carried by a 65-foot Black Brant 12 rocket, a sub-orbital vehicle used frequently by scientists at Wallops. The rocket is programmed to climb 180 miles above the Earth—much higher than the altitude of natural noctilucent clouds—and 98 miles down range (east) from Virginia’s Atlantic Shore.

Observers should watch for the cloud to be released about six minutes after launch. If skies are clear, the sinuous white cloud should become visible low in the southern sky after its release.

You can follow the launch via Webcast, on Twitter, or by phone at 757-824-2050.

And as always, those who see it are invited to come back here and leave comments describing the event for those who miss it.

At 110 stories, the World Trade Center twin towers were tall enough for the Sun to set nearly two minutes later for people on the top floors than for people on the bottom floors.

City of Stars article: Sunset on the World Trade Center

As always, but especially today, keep looking up.

-NDTyson

On Tuesday (Sept. 8, 2009) and Wednesday (Sept. 9, 2009) the New York metro area will have three great opportunities (local weather conditions permitting) to see the Space Shuttle Discovery and the International Space Station flying in tandem across our evening sky.

Currently, Discovery is docked to the Space Station, but at 3:27 p.m. on Tuesday it will undock from the Station and slowly begin to pull away from it.

On Tuesday, at 7:42 p.m., both Discovery and the Space Station will rise above the SSW horizon and will track toward the ENE. They will appear as two bright moving "stars." Discovery will appear to lead the Space Station across the sky. The Space Station, however, should appear as the brighter of the two objects. They will be separated by roughly 5 or 6 degrees; your clenched fist held at arm's length measures roughly 10-degrees, so the Shuttle and Space Station will be separated by about a "half fist" as they move across the sky. At their highest point, they will stand 33-degrees above the SE horizon and at 7:44:30, as an added bonus, they will pass directly above the planet Jupiter. This pass should take 5 minutes 17-seconds from start to finish.

Also on Tuesday evening, a second pass will begin at 9:18 p.m. Discovery and the Space Station will appear a little farther apart. They will rise above the W horizon and will track toward the NNW. After 2 minutes 29 seconds, however, they will rapidly fade out, 25-degrees above the horizon, as they pass into the Earth's shadow.

On Wednesday, comes the third and final double pass. The two space vehicles will be much farther apart ... the Shuttle will lead the ISS by about one minute. Watch for Discovery at 8:05 p.m. rising above the WSW horizon, moving toward the NE; the Space Station will follow along the same track about a minute later. At their highest point, they will stand 64-degrees above the NW horizon. This pass should take 5 minutes 42-seconds from start to finish.

Discovery is scheduled to return to the Kennedy Space Center in Florida on Thursday (Sept. 10) at 7:06 p.m.