SLOOH Skylog

For a third straight week, we have yet another opportunity to observe a near-Earth object, this one passing at just 4.1 LD on October 29th!

NEO 2005 VN is a 100m (300ft) asteroid discovered in 2005, a mere two days before passing within 17 LD of our planet. That discovery was made by LINEAR on November 2, 2005.

The last quarter of that year, 2005, was a busy time for discoveries in our near-Earth neighborhood, with several objects being discovered only after they had passed our planet. While a handful were small meteoroids, measuring anywhere from 5m to 30m, as many others were larger asteroids measuring many tens of meters to as much as 1km.

One of the smaller objects, 2005 WN3, actually passed less than a quarter the distance of the moon just seventeen hours after its discovery. The very next day, another small object, 2005 WY, passed at only 2LD six days after its discovery. Then, ten days later, yet another small object was discovered just two days before passing within a mere 0.6LD.

All totaled, the months of October, November, and December of that year saw fifty-five new discoveries, with a dozen of those objects passing less than 10LD from Earth, several of them before they were even discovered.

Our latest NEO, 2005 VN, will be featured with two Mission Alerts on Tuesday night, at 20:25 UTC and 22:00 UTC - that’s 4:25pm EDT and 6pm EDT. We’ll target it through the Slooh telescopes as it slips through the constellation Draco; and we’ll talk about its discovery, as well as several others in those last few months of 2005, on SloohRadio.

If you’re new to Slooh, or just new to our NEO events, this article, discussing last week’s near-Earth event, explains what you can expect to see through the Slooh telescopes. You’ll also find many NEO images and animations in the Slooh User Forums. And if you have any questions or would like to meet some of your fellow Slooh members, visit us in the Slooh chatroom. You’ll find chatroom access buttons in the left-side menu of the Slooh Launchpad and in the bottom left corner of your Mission Interface.

WHAT: Near Earth Asteroid 2008 TT26

WHEN: October 20/21 and October 22/23

WHERE: Member Channel and SloohRadio

On October 23, 2008, NEO 2008 TT26 will pass less than four lunar distances from our planet, and we‘ll target the event with three Mission Alerts, featuring live missions through the Member Channel and SkyGuide commentary on SloohRadio.

On Monday night, at 21:00 UTC and 02:15 UTC (that’s 5pm EDT and 10:15pm EDT) we’ll observe the approach of this near-Earth asteroid; and then on Wednesday night at 00:30 UTC / 8:30pmEDT, we‘ll witness its actual near-Earth pass. That’s three different alerts, each featuring three back-to-back missions, for plenty of real-time imaging opportunity.

Through the Slooh telescopes, 2008 TT26 will probably appear as a multi-colored segmented line, not as the single star-like object that we often see with more distance asteroids like Ceres and Vesta. Its appearance will illustrate both its close proximity and its speed, with each color filter exposing the quickly moving object in a new location. While even the largest optical telescopes cannot reveal actual physical details of an object like 2008 TT26, it is Slooh’s real-time observations and what the images represent that make events like this such a unique and exciting Slooh experience.

At 49m - 110m (160ft - 360ft) 2008 TT26 is considered a small asteroid. Nonetheless, it is large enough to be potentially devastating in an impact. To compare, Arizona’s Barringer Meteorite Crater was created by a 46m (150ft) object. That impact resulted in a 20-40 ton megablast which produced winds in excess of 1,000km/hour, thermal emission burn damage extending out to 10km, and the scattering of more than 30 tons of iron debris over an eight-mile-wide area. Fifty-thousand years later, there remains a hole nearly one mile wide and 570 feet deep. An impact of this magnitude, today, would destroy a city.

At its closest point, 2008 TT26 will pass within a mere 3.6 LD of our planet. That’s about 860,000 miles or 1.4 million kilometers. Here on Earth, 860,000 miles is a tremendous distance; but in space, 860,000 miles is close enough to warrant legitimate concerns about future passes. Any number of scenarios could influence this near-Earth object’s trajectory and result in a more direct approach toward our planet.

Probably more disconcerting than its size and distance is the discovery date of 2008 TT26, which occurs just fourteen days before its predicted near-Earth pass. Such a timeline, especially with an object the size and distance of this asteroid, underscores the importance of various spaceguard endeavors. What if this object were on a more direct impact path? Would two weeks be enough time to prepare; and what exactly would we do? These are very legitimate, even urgent, questions when one considers Earth’s known impact history and the likelihood of future impacts.

2008 TT26 was discovered October 09 by LINEAR, one of several worldwide spaceguard projects around the globe. The LINEAR project utilizes a pair of Ground-based Electro-Optical Deep Space Surveillance (GEODSS) telescopes located at its Experimental Test Site in Sorocco, New Mexico. LINEAR is an MIT Lincoln Laboratory program and is funded by NASA and the USAF. The project’s stated mission is “to demonstrate the application of technology originally developed for the surveillance of Earth orbiting satellites, to the problem of detecting and cataloging near-Earth asteroids that threaten the Earth.” To date, LINEAR has discovered more than a quarter-million asteroids and over 2,000 near-Earth objects.

Mark your calendar to join one or all three of our Mission Alerts to watch as NEO 2008 TT26 makes its way past our planet next week. We’ll target it through the Slooh telescopes and talk more about it on SloohRadio. If you haven’t yet done so, be sure to visit the Slooh Chatroom. Events like this are much more fun when shared with fellow astronomers and enthusiasts.

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 12^th 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.

__________________________________________________

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:

From TaviG., using Photoshop Elements 6:

From Aloysius O., using Windows Movie Maker:

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 13^th 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.

Tonight, lost within the orange glow of the setting sun, a newly discovered asteroid passed within 84,000 miles of our planet, just a third of the distance to the Moon, and barely anyone noticed. A sharp-eyed skywatcher with a good pair of binoculars might have seen the unfamiliar object gliding silently through Aquarius. But did they know what they were seeing was a very unexpected asteroid? Would they have understood just how close it really was?

Near-Earth Object, 2008 CT1, was discovered only two days before tonight’s close pass by the Lincoln Near-Earth Asteroid Research project, an MIT project funded by the USAF and NASA committed to discovering space rocks that orbit near Earth. Using robotic telescopes located at New Mexico’s White Sands Missile Range, the project has contributed nearly 70% of world-wide Near-Earth Asteroid discoveries since beginning operations in 1998.

Tonight’s asteroid, estimated between 8m - 15m wide, sounds small as asteroids go, but recent studies suggest that even smaller rocks can be devastating. The cause of the Tunguska Event of the early 20^th Century is now believed to be a 35m rock that never even touched the surface. The new hypothesis suggests it exploded a few miles above the ground, creating a shockwave that wreaked havoc on the ground beneath. Just last September, the Earth-impacting meteorite that created a 13m wide crater in Peru is estimated to have been just 0.2m - 2m wide.

Tonight’s pass was very close on a cosmic scale - and its late discovery makes it an even closer call. Asteroid 2007 TU24 got a lot of media attention last week, but we knew that one was coming and where to look. We even caught a glimpse on Slooh. With all the telescopes pointed to the heavens, watching the skies for that next great impactor, there are still rocks that slip by unnoticed. Observing close encounters with known asteroids is a great opportunity to learn more about our Solar System, and how to spot future Near Earth Objects - even those not on our radar yet.