Category Archives: Asteroids

Going to Bennu

On 08 September 2016 NASA will launch the OSIRIS-REx mission to the asteroid Bennu.  Arriving in 2018 and after thoroughly mapping the asteroid a 2.1 ounce / 59.5 gram sample will be collected and returned to Earth.

More about OSIRIS-REx



2016 CG18 Coming Tomorrow


2016 CG18 is a newly discovered asteroid and it will pass very close to us tomorrow (06 Feb), just 0.39 Lunar Distance or 149,916 km / 93,153 miles away.  The closest point will occur at 13:29 UTC.

149,000 to 150,000 km is really close in cosmological terms fortunately there isn’t any worries about 2016 CG18 getting any closer for a while.  Orbital calculations shown at ESA’s  NEODys-2 site show this is the closest approach until at least the year 2100.

The most remarkable thing about the asteroid is that it is only 7 meters across and the Catalina Sky Survey was able to find it on 03 February — that’s really good!

Image: JPL / NASA hat tip to Ron Baalke

UPDATE:  Just learned of another asteroid called 2015 NJ3, this is termed as a “Potentially Hazardous Asteroid”, NOT that is is a danger anytime soon that we know of but one that bears watching.  Preliminary data is just out, more to come.

Christmas Eve Visitor

2003 SD220 is a large asteroid that passed by Earth on 24 December 2015.  This image from  NASA’s 230-foot (70-meter) Deep Space Network antenna at Goldstone, California on 22 December 2015.


The 2.4 km / 1.5 mile long asteroid passed just 11 million km / 6.8 million miles which is pretty close in astronomic terms.  It will pass even closer in 2018 when it will be just 2.8 million km / 1.8 million miles away.


This second radar image was taken on 17 December 2015 when the asteroid was 12 million km / 7.3 million miles away.


Image: NASA/JPL-Caltech/GSSR


Asteroid to Make a Close Encounter

Radar images are improving as this video of 1998 WT24 shows.  Only 400 meters across and 4.3 million km / 2.7 million miles away, this is great resolution.

We have a VERY close encounter coming up today.  At 12:07 today Asteroid 2105 YB is going to pass just 0.2 LD from the Earth.  Thats only 76,880 km / 47,770 miles, very close indeed.  Note there is some uncertainty of the time of closest passage, it’s possibly up to 1.7 hours off.  2105 YB is 10 meters in diameter and was only discovered a few days ago so the number of observations are limited so far and as you can imagine these things are terrifically hard to see.

More observations will improve the accuracy of predicted future positions.  2105 YB might make a good choice for a radar target as any asteroid this close could (not saying it does) pose a potential risk.



Halloween Asteroid Update


This updated set of images of the Halloween asteroid released yesterday.  Very nice detail for radar images.  Be sure to click the image above for a larger version.

Asteroid 2015 TB145 is depicted in eight individual radar images collected on Oct. 31, 2015 between 5:55 a.m. PDT (8:55 a.m. EDT) and 6:08 a.m. PDT (9:08 a.m. EDT). At the time the radar images were taken, the asteroid was between 440,000 miles (710,000 kilometers) and about 430,000 miles (690,000 kilometers) distant. Asteroid 2015 TB145 safely flew past Earth on Oct. 31, at 10:00 a.m. PDT (1 p.m. EDT) at about 1.3 lunar distances (300,000 miles, 480,000 kilometers).

To obtain the radar images, the scientists used the 230-foot (70-meter) DSS-14 antenna at Goldstone, California, to transmit high power microwaves toward the asteroid . The signal bounced of the asteroid, and their radar echoes  were received by the National Radio Astronomy Observatory’s 100-meter (330-foot) Green Bank Telescope in West Virginia. The images achieve a spatial resolution of about 13 feet (4 meters) per pixel.

Image Credit: NASA/JPL-Caltech/GSSR/NRAO/AUI/NSF

Pushing Asteroids

A rotating asteroid heats up in the sunlight side and as the warmed area rotates into the dark and cold, the stored heat is radiated away. The heat radiated into the cold can cause thrust and push on an asteroid.

The amount of “push” wouldn’t be much, yet over time it can add up and cause the asteroid to change their paths. If you have followed the talk about how to divert a potentially dangerous asteroid you will know variations of this theme has come up.

Asteroid With a Moon

Asteroid 2004 BL86 made a relatively close pass yesterday. The asteroid passed about 3.1 lunar distances from Earth or 1.2 million km / 745,000 miles. In cosmic scales that is indeed close. The asteroid is 325 meters / 1,100 feet in diameter, not something we would want to hit us!

Scientists used the Deep Space Network antenna at Goldstone California took took radar images of the asteroid and assembled 20 of them into this video and look at what they found – the asteroid has a moon! Actually about 16 percent of the near-Earth population of asteroids of 200 meters in diameter (655 feet) have moons and a few have two. This particular moon is 70 meters (230 feet) across.

The observations of the asteroid enabled scientists to get data on the orbit to predict future close passes and this asteroid will not make another pass this close for 200 years. We do have others though, the next known asteroid to make a close pass is called 1999 AN10 in 2027.

The asteroid was found on Jan. 30, 2004, by the Lincoln Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico, one of a handful of observing groups around the world looking for these very difficult to find objects.

Video source