Photo of Tavi Greiner

Slooh Mission Alert: Near-Earth Asteroid 1996 HW1

WHAT: Near-Earth Asteroid 1996 HW1

WHEN: Friday, September 12

WHERE: Teide’s Member Channel and SloohRadio

Every day, various solar system objects; like meteoroids, asteroids, and even comets; pass within close distances of our planet. While most are smaller nearly-invisible debris, some are large enough and close enough to pose a threat. A few are even bright enough to be observed through average-sized telescopes.

NEA 1996 HW1 is both large and bright, and it is quickly approaching Earth. This Friday, telescopes all around the world, including Slooh’s Teide Observatory, will target this object as it slips silently past our planet. Data will be acquired, images will be taken, and more will be learned in a continuing endeavor to protect our planet against potential impacts

Just how big and bright is 1996 HW1, and how closely will it pass? Original radar measurements estimate its size at 2.3km – 5.2km wide, but ongoing observations continue to fine-tune that number. It is reasonably bright at 12th magnitude and currently visible in the constellation Pisces. As for how closely it will pass, NEO distances are often compared to the moon’s as lunar distances. Our NEO of topic will pass within 53 LD. That equates to about 20 million kilometers - a large number in everyday terms, but a very close distance by astronomical standards.

This Friday, September 12, at 6:10pm EDT / 2210 UTC, we’ll feature NEA 1996 HW1 with live missions and commentary. We’ll watch the near-Earth pass through the Teide telescopes and hear more about this and other near-Earth objects from one of the Slooh SkyGuides on SloohRadio. You can even join us in the Slooh Chatroom to enjoy the event with fellow Slooh members.

Preview: This animation, comprised of six Slooh images taken across a 30-minute timespan, shows 1996 HW1 passing through the constellation Pegasus less than two weeks ago.

NEO1996HW1animation

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After-show Notes, 2008Sept13:

I noted a couple of websites during our Mission Alert, last evening. Those were 1) the Earth Impact Effects Program from the University of Arizona’s Lunar and Planetary Laboratory, an interactive feature for estimating the regional environmental consequences of an impact on Earth; and 2) the FMO Project, a volunteers discovery program once offered by the University of Arizona’s Spacewatch Project.

The following animations, created from last evening’s Mission Alert, illustrate both the results of our live missions and the various methods that can be used to give motion to still images:

From DaveM., using Gimp:

DaveMs1996HW1

From TaviG., using Photoshop Elements 6:

NEA1996HW1AtClosest

From Aloysius O., using Windows Movie Maker:

Photo of Tavi Greiner

Approaching Near Earth Object Revealed As Triple System

The International Astronomical Union announced Tuesday that approaching NEO 2001 SN263 is actually a triple asteroid system. Arecibo radar images revealed the unique triple space rock that was previously believed to be a binary system. While the discovery of a triple-system is not unique, this is the first accomplished by radar and the only such discovery within the Near Earth Asteroid population. Astronomers estimate their diameters at 2km, 1km, and 400m.

The radar team, headed by Principal Investigator Mike Nolan of Arecibo, revealed 2001 SN263 as a triple-system with images obtained on February 12. Coincidentally, that’s the same day we captured live images on Slooh to create this asteroid animation - illustrating the NEO’s movement through Auriga and towards our planet.

The LINEAR Project originally discovered the asteroid in September 2001 and a team of seven astronomers from France’s Haute-Provence Observatory identified it as a possible binary-system in January 2007. It is an AMOR object, passing close to Earth every few years, but never actually crossing our orbit. This time around, 2001 SN263 will pass within 25.6 Lunar Distances on February 20. Currently, it’s visible at 13th magnitude in Auriga, where it will remain for the next two days before slipping into Gemini. By the time of its closest pass, this NEO will reach a brighter magnitude of 12.4.

We’ll be following 2001 SN 263’s approach through the Slooh telescopes, as weather allows. If you would like to catch a glimpse yourself, you can check the Member Missions thread of the Slooh Forum for dates and times.

arecibo.jpg