NM observatory part of asteroid deflection project
Latest ‘close call’ happened just a week ago, missing Earth by 745,000 miles
SOCORRO — Objects from space enter the Earth’s atmosphere every day, ranging in size from a grain of sand to a small car.
Most enter the atmosphere unnoticed, and some are seen as meteors or shooting stars.
One of the missions of New Mexico Tech’s Magdalena Ridge Observatory involves tracking such celestial bodies, as well as objects that are large enough to destroy a city, or worse, those that are catego- rized as “global killers.” Such large objects have hit our planet in recent times.
In February of last year, a previously undetected meteor fell near Chelyabinsk, Russia, that damaged buildings and resulted in about 1,500 injuries.
In 2008, a large object from space caused a 1 kiloton explosion over the Sudan.
In 2002, a large asteroid exploded in the upper atmosphere over the Mediterranean Ocean.
In 1908, one of the largest asteroid impacts recorded in modern times occurred in Tunguska, Russia. It was estimated to cause an explosion equivalent to 1,000 times greater than the
atomic bomb dropped on Hiroshima in 1945.
The Near-Earth Object Observations Program, commonly called Spaceguard, discovers these objects, characterizes a subset of them and plots their orbits to determine if any could be potentially hazardous to our planet.
New Mexico Tech is one of six members of Spaceguard. Tech’s 2.4-meter telescope at the Magdalena Ridge Observatory is one of the three funded telescopes that characterizes the newly found asteroids.
Eileen Ryan, project scientist and manager of the MRO’s 2.4-meter telescope, said the latest “close call” was last Monday night from a rock designated 2004-BL86, first tracked by the observatory in 2004.
“This one was very big, the size of five football fields,” she said. “If this guy hit us, it would really be a large impact. It would be unprecedented in terms of damage, or if it fell in the ocean no doubt would cause tsunamis.”
In astronomical terms, the asteroid was close, missing Earth by only 745,000 miles.
“That’s about three times the distance to the moon,” Ryan said. “Recently, a lot of them have been coming very close, and it’s almost getting routine now, because there’s so many of them passing this close. This is one of maybe two dozen that have passed close in the last few months but is maybe twice the last one that came by.”
Since 2008, Ryan and other astronomers at the MRO have been tracking and studying asteroids, but now they are taking asteroid studies one step further.
“There is a potential spacecraft project that we’re going to be working on for NASA and the Applied Physics Lab at Johns Hopkins University in April,” Ryan said. “It’s the Asteroid Impact and Deflection Assessment project or AIDA for short.”
The ultimate goal of the project is to find out if an asteroid can be deflected, and a binary asteroid has been selected for the test.
“It’s two asteroids orbiting each other,” she said. “Our facility has been selected as one of a handful of observatories to get rotation and information about the system.”
The spacecraft would take three years to reach the asteroid Didymos and its companion. The main asteroid measures about one-half mile across. It is orbited by a smaller asteroid of about 490 feet.
“The coolest thing about this spacecraft mission — AIDA — is that they’re actually going to try to hit the small object orbiting the big object,” she said. “They’re asteroids orbiting each other, and AIDA will hit the little one and we’ll see how it changes that guy’s orbit.”
Ryan said this would be the first real data on how these two objects orbit each other and how their spin rates are evolving.
“We’ll learn a tremendous amount of physics about how that needs to be done. Do we need nuclear explosives? Can we do with kinetic impact? All of that will be revealed as a result of this experiment,” she said.
“We will have a much better idea of what needs to be done if an asteroid is headed towards us and we have to deflect it. Hopefully, we’ll be able to go forward with a launch in the near future, say within five years. Then we can have better handle on how we can protect the Earth from things that are the size of five football fields that are coming so close.”
Ryan said the project is in collaboration with the European Space Agency.
“The U.S. is building the impacter, and Europe is building the rendezvous spacecraft that will also be taking pictures of what happens. It’s a really nice way to foster cooperation worldwide.”
As for Monday’s asteroid pass-by, Ryan said, “We’re excited about close approaches like this because it helps us understand what the threat might be and kind of pushes people in the right direction to put money into resources to learn what we should do.”
Ryan said Monday’s particular close approach “really drives the point home for future missions where a lot of astronauts and other major players in the space business have been advocating.”
“They say, ‘We can do some science, we can learn about these two asteroids, but also let’s do an experiment that saves us time and effort and try to get real hard data so that we feel that we have defense of the Earth under control,’ ” she said.
In the meantime, MRO scientists and astronomers, working with the Jet Propulsion Laboratory and NASA’s Spaceguard program, already have developed a computer model to predict where and when a possible catastrophic collision would occur.