Asteroid to miss Earth by less than 20,000 miles next month


January 14, 2013

An asteroid passing close to Earth next month will provide stargazers with a rare viewing opportunity (Image: Shutterstock)

An asteroid passing close to Earth next month will provide stargazers with a rare viewing opportunity (Image: Shutterstock)

Image Gallery (4 images)

Asteroid 2012 DA14 is about 40 meters (131 ft) in size, has a mass of 130,000 tons, is traveling relative to the Earth at a speed of some 6.3 km/s (14,100 mph) ... and will miss us by less than 32,000 km (20,000 miles) on February 15. If it did hit the Earth, the result would be a huge explosion yielding about 2.5 megatons, but Asteroid 2012 DA14 will not hit our planet in 2013, and probably never will. Despite the lack of a sensational scenario, this close call still warrants our attention – it will allow astronomers to learn a good deal about asteroids, and represents one of the few chances for ordinary folks to see a asteroid pass really close to Earth.

2012 DA14 was discovered on February 22, 2012 by LaSagra Observatory in the mountains of Andalusia in southern Spain. The find was made about seven days after the asteroid passed within about 2.6 million kilometers (1.6 million miles) of Earth on its slightly elliptical 366 day orbit around the Sun. This elliptical orbit is slightly tilted relative to that of the Earth, so that it passes near Earth twice each year.

The path of 2012 DA14's close pass past the Earth on Feb. 15, 2013 (Image: NASA)

On February 15 this year, 2012 DA14 will make another – extremely close – pass by the Earth. The latest calculations show that the distance of closest approach will be about 34,100 km (21,200 miles) from the center of the Earth, or about 27,700 km (17,200 miles) from the Earth's surface. This is well below our encircling ring of geosynchronous satellites, which orbit at a distance of 42,160 km (26,200 miles) from the Earth's center.

Observing 2012 DA14

The asteroid will pass rapidly from the southwest to the northeast, being seen in dark skies through most of Europe, Asia, Africa, and Australia. For these locations, 2012 DA14 will appear brightest (magnitude 7) at about 19:50 UT, and should be visible in good binoculars along much of its path. It will move quickly through the sky – at closest approach the asteroid will appear to move about the Moon's diameter each minute.

I have prepared finder charts for 2012 DA14 based on the NASA/JPL HORIZONS ephemeris as a guide to finding the asteroid.

It is close enough to Earth that its position in the sky depends on your location, owing to the effects of parallax. To accommodate for this I have charted 2012 DA14's path as seen from Tokyo, Japan, and from London, England.

Chart of 2012 DA14's path through the northern skies (Image: B. Dodson)

Chart of 2012 DA14's path through the southern skies (Image: B. Dodson)

The yellow lines connecting the London and Tokyo paths show approximately where to find the asteroid from intermediate longitudes. Unfortunately, by the time night rolls around in the Americas, 2012 DA14 will be very far north, and rapidly diminishing in brightness.

More than 500 major observatories and radio telescopes have observing programs designed for this unusually close pass. Why not join them and become one of the few people ever to see an Earth-grazing asteroid?

Source: NASA/JPL-Caltech

About the Author
Brian Dodson From an early age Brian wanted to become a scientist. He did, earning a Ph.D. in physics and embarking on an R&D career which has recently broken the 40th anniversary. What he didn't expect was that along the way he would become a patent agent, a rocket scientist, a gourmet cook, a biotech entrepreneur, an opera tenor and a science writer. All articles by Brian Dodson

Although unlikely, I wonder if it will collect any geosynchronous satellites?


@Oaksey: The asteroid is traveling northwards through Earth's equatorial plane, on a path like a string through a wedding band. All the geosats are on the perimeter of the ring, not in the space between Earth and the ring. It's a very safe region for the visit, as there is generally speaking no "traffic" through there...


David Bell

Maybe now would be a good opportunity to test one of the techniques for changing the course of an asteroid to avoid a collision with earth.


The Wikipedia says the moon is 356,400 km to 406,700 km from the Earth, so this thing is much closer. Hopefully the gravitational force of the moon and/or the planet Earth won't be enough to break any loose pieces off, and cause them to wipe out a city.

Thomas Prewitt

Thomas Prewitt, the whole asteroid is being attracted by the Earth, not just some pieces. So not a single piece of sand of its surface will hit Earth, unless it hit a satellite or some air particles of course. The asteroid is going to be falling towards Earth, and when skydivers fall their arms and legs don't fall off.

Artem Down

If my numbers are correct, it will get as close as 2.0 earth diameters from the earth's surface. That's a close miss!


Sorry. It's rather about 2.2 earth diameters from the surface.


phew! Now what exactly could we do about it? If it were to hit.


If this asteroid hit earth it could scare the nations of earth enough to help us prevent the next nuclear war. A lot like the plot of the watchmen but with a far more realistic chance of occuring. 20,000miles is nothing. A small change in solar wind could ensure this asteroid hits our planet. Plus, think of all the money that nasa a federal asteroid control programs will recieve from the asteroid central homeland command


re; MasterG

Nuke the hell out of it if it was going to hit something we value and can't move or evacuate the impact area.


Thank you for an incredibly informative & detailed article.

Alan on Palawan

With an asteroid that comes close to Earth so regularly, why not land a probe on it?

Plonk down telescopes on several of these rocks and they'd build up to an insanely huge synthetic aperture telescope.

Putting their data together should be easy with today's computing power. There's a twin pair of small radio telescopes in the USA and Chile, operated by very old Macintosh IIci computers.

If a IIci (roughly equivalent in power to a 25Mhz 80386 PC) can process radio telescope data, go shopping at Wal Mart or Tiger Direct for the boxen to run the Asteroid Synthetic Aperture Telescope.

Gregg Eshelman

re; Gregg Eshelman

Did you see how fast the rock is going? Any attempt to use the rocks closeness to save fuel would result in a new crater on the rock. The only advantage placing the telescope on asteroids is the mass of the rock will damp vibrations caused buy the heating and cooling effects of passing through shadows. In free orbit around the sun that would be too rare to worry about.


"slightly elliptical 366 day orbit around the Sun. This elliptical orbit is slightly tilted relative to that of the Earth, so that it passes near Earth twice each year." Would be curious what the variation in distance from Earth (centre) each time it does a close pass. Obviously this thing has made a million passes so it’s not likely to chip the earth any time soon, so not worried.

Though I would be curious how influential its gravity might be on the geostationary satellites in the vicinity. Must be a hell of a thing to take into account (mathematically) when considering placing a new geo up there knowing 2012 DA14 does a close swoop twice a year.

If it was only discovered last year, how is it we haven’t had any satellites being knocked out already? Quietly chuckles at the thought that previous satellites ‘disappearing’ due to DA14 were blamed on ‘the other side’s space based missile defence shield’ when neither side knew who did it.


This asteroid crosses the earth's orbital plane twice a year. Because they have slightly different orbital periods, they do not come close every time DA14 crosses earth's orbital plane. Using Solex a solar system numerical integration program with orbital elements from NASA JPL, I obtained the following distances for approaches within 10 000 000 km in the near future: Date TT Dm (Gm) V(km/s) 2013/02/15 19:25:49 0.034101 7.8178 2046/02/16 04:45:49 1.226068 6.1823 2077/02/17 02:17:54 4.892847 6.1819 2083/02/14 00:17:07 6.244430 6.4073 2114/02/14 22:21:11 5.016080 6.3462 2133/02/17 10:44:03 3.726149 6.1635



Thanks for sharing that Nadir. Could someone answer this question please? Is it possible to send a probe there? @Slowburn said that it's not possible. I'm no rocket scientist but would it be possible to send a probe into closer to the sun solar orbit and catch it from behind? Could it be a good candidate for asteroid mining? Please feel free to prove me wrong.

Edgar Walkowsky
Post a Comment

Login with your Gizmag account:

Related Articles
Looking for something? Search our articles