Astronomers Corner The Market In Near-Earth Objects
New Mexico Tech’s 2.4-meter telescope is quickly making a name for itself in the world of astronomy. Magdalena Ridge Observatory astronomers made yet another contribution to space situational awareness in November, adding to the facility’s impressive array of finds.
Bill Ryan was scanning the night skies Tuesday, Nov. 16, at the Magdalena Ridge Observatory when he trained the 2.4-meter telescope at a close, yet harmless, asteroid.
The flying rock, called Asteroid 2010 WA, is the second-fastest spinning asteroid ever seen, observatory director Dr. Eileen Ryan said. Asteroid 2010 WA flew within 18,000 miles of Earth that night. The asteroid was less than 5 meters across and posed no threat of hitting Earth, she said. However, the rock did pass within the zone of satellites in geosynchronous orbit, Ryan said.
The relative harmlessness of asteroid 2010 WA did not make it any less interesting to scientists.
“We measured the rotation rate of the asteroid at about 31 seconds,” said Eileen Ryan. “This was a target of opportunity for this particular asteroid. It’s so small that it may only come close enough to the Earth for us to observe it once in a decade or longer.”
The fastest spinning asteroid currently known is called 2010 JL88, which spins once every 24.5 seconds and was also discovered in May 2010 by Bill Ryan using Magdalena Ridge Observatory’s 2.4-meter telescope.
Bill Ryan said astronomers previously believed that objects that were not solid could not spin faster than every two hours. Now, based on new observations, scientists accept that objects can spin much faster than that with just a small amount of internal strength.
“Our colleagues have encouraged us to try and push our observational limits to build up the data set of very fast rotators and examine its implications to the internal structure of small asteroids,” he said.
Vice President of Research Dr. Van Romero said he’s somewhat surprised that the Tech facility is producing such impressive results so early in its operational life.
“If you would have asked me a few years ago, I would have said that we didn’t have the capability to observe objects this small and determine their rotation rate,” he said about the telescope which first became operational in late 2008.
Romero said the Magdalena Ridge Observatory is quickly making a name for itself with these groundbreaking discoveries.
“Bill Ryan has begun to corner the market on these fast rotators,” Romero said. “It appears that the combination of the telescope’s design and Bill’s observing capabilities are outpacing what other facilities are capable of.”
Despite its small size, the asteroid appeared as a bright object for a brief period, Eileen Ryan said. The Magdalena Ridge Observatory’s 2.4-meter single telescope was purpose built for tracking near-Earth objects and satellites. Ryan said the telescope’s unique design — at 10 degrees per second, one of the fastest in the world — and specialized cameras give New Mexico Tech unique capabilities for tracking these near-Earth objects.
“If an asteroid completes a rotation every 30 seconds, you have to take a massive amount of images quickly,” Eileen Ryan said. “We have unique cameras that can take quick exposures and we can track these guys even when they are blazing fast.”
Every night, astronomers around the world identify 12 to 15 new asteroids. The Ryans — a married couple — review the recent discoveries and look for small, fast objects they can track and study in more detail. The National Science Foundation and NASA combine to fund 10 nights per month of observing time at the MRO to track small, faint asteroids. Asteroid 2010 WA was just discovered the previous night.
“We were at the right place at the right time to gather data,” Eileen Ryan said. “Most telescopes are booked months in advance and don’t have blocks of time available. Since we have NASA and NSF support, we are happy to be hunting around and looking for these great opportunities.”
Bill Ryan said studying newly discovered asteroids is a thrilling endeavor for an astronomer.
“Many years ago when I was sharing an office with Clyde Tombaugh, he described the feeling of being, at least for a few hours, the only person in the world to know of Pluto’s existence,” Ryan said. “Although not nearly as intense, it is still kind of exciting when our initial tracking — and a quick calculation — tells us ‘This one is going to be close, close enough to take out our TV satellite.’ I have to restrain the feeling of wanting to wake someone up to share the news.”
The next time Asteroid 2010 WA will come near Earth will be in September 2013, but that transit will occur much further from Earth — too far for the MRO 2.4-meter telescope to view, Ryan said.
In its brief existence, the 2.4-meter telescope has already tracked and characterized almost 50 asteroids, Ryan said.
“We’re building a strong database so we can make conclusions,” she said. “We’re hoping to acquire a nice statistical sample so we can gain scientific insights regarding the physical nature of these small bodies. Ultimately, we want to find one that gets torn apart because it’s spinning so fast. That would provide even more information about the strength of these objects.”
By developing an accepted model of the strength of asteroids, scientists and engineers would be better able to devise a plan for deflecting or destroying larger asteroids that might pose a threat to Earth, Ryan said.
Contact Thomas Guengerich