Undue Ado About Asteroid 2013 TV₁₃₅

By: J. Kelly Beatty October 18, 2013 10

On October 8th, Russian astronomers spotted a largish near-Earth asteroid discovered that had passed Earth's vicinity three weeks earlier. For the moment, there's a 1-in-14,000 chance that it will hit us in 2032.

Update, November 4th:According to new calculations by NASA's Near-Earth Object office, the likelihood that this asteroid will collide with Earth in 2032 has dropped to about one in 21 million.

Here we go again. Back on October 8th, when most of us were distracted by the U.S. government shutdown, Gennady Borisov and Timur Kryachko made a nifty discovery with an 8-inch (20-cm) astrograph at the Crimean Astrophysical Observatory. Their find, asteroid 2013 TV₁₃₅, was only 17th magnitude as it cruised through central Camelopardalis. But it turned out to be a near-Earth asteroid that had swung by Earth on September 16th at a distance of 4.2 million miles (6.7 million km).

A visit by asteroid 2013 TV<sub>135</sub>

Based on early observations, the near-Earth asteroid circles the Sun every 2.46 years in a low-inclination, high-eccentricity orbit. It came close to Earth in mid-September 2013 and might come much closer in August 2032.

NASA / JPL / NEO Science Office

More importantly, based on its preliminary orbit, this object will be coming past Earth again — perhaps uncomfortably close — on August 26, 2032. Given its estimated diameter of 1,300 feet (400 m), 2013 TV₁₃₅ could make an Earth-shaking splat if it were to hit.

But I'm not marking my long-term calendar for this one. Right now the odds of a collision are about 1 in 14,000 according to NASA (an update from the initial 1-in-63,000 odds) and 1 in 7,500 according to the University of Pisa's NEODys team.

Those orbital calculations are very rough, computed from only a few dozen observations made during the past 10 days. "TV₁₃₅ will remain observable through next March," notes veteran solar-system observer David Tholen (University of Hawaii). "Most likely, this one will drop from the risk list long before then."

Nonetheless, there's plenty of hoopla over this incidental interloper, fueled initially by Russian news reports and later by sensational headlines in British tabloids.

A short exposure with a 17-inch robotic telescope captured the asteroid 2013 TV₁₃₅ (inside red circle) at 20:53 Universal Time on October 17, 2013. At the time the interloper was magnitude 17.8 and moving away from Earth. A short exposure with a 17-inch robotic telescope captured the asteroid 2013 TV₁₃₅ (inside red circle) at 20:53 Universal Time on October 17, 2013. The relatively bright star just below it is a close pairing of BD+65486B and HD 37337.

Gianluca Masi / Virtual Telescope Project

In fact, all that unfounded worry is the only reason I'm writing this. NASA's celestial dynamicists even felt the need to issue a "reality check" yesterday about 2013 TV₁₃₅. "The current probability of no impact in 2032 at about 99.998%," says Don Yeomans, who manages NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in California.

Don't blame Borisov and Kryachko for this. Both are well-regarded observers — Borisov for his discovery of comet C/2013 N4 earlier this year and Kryachko for his variable-star work.

Give the bright Moon a few days to get out of the way so more observations can be taken, and I predict 2013 TV₁₃₅ will become the latest in a decades-long list of asteroids that got everyone needlessly rattled.

Comments

adolfo rufatt

October 18, 2013 at 2:48 pm

The concern is not about 2032 but that we saw it almost a month AFTER it went by...