Saturday, 21 October 2017 14:31

Asteroid 2012 TC4

On Oct 12, 2017, a small asteroid zoomed past Earth just outside the range of our geosynchronous satellites.

First discovered in October 4, 2012 during it's last close approach. It will make several more approaches in the coming decades, but nothing as close as this one. Next closest approach will be in October 2050.

Size is estimated 15 meters, with a non-spheroid shape, and has  a fast rotation with a rotational period of only 12 minutes and 14 seconds.

A single 60 second exposure as the asteroid zoomed across the field of view.


Published in Solar System Objects
Thursday, 14 September 2017 15:19

Asteroid 3122 Florence Close Approach

On the night of August 31, I imaged the asteroid Florence which made a relatively close pass of Earth. At a distance of 4.4 million miles, it is one of the larger near Earth asteroids. With a size of 2.7 miles, any collision would not be good news, but luckily no collisions are forecast for the foreseeable future. It won't come this close again until after the year 2500.

Stacked and merged image showing its path across the sky


Animated Gif imaging showing its motion over an hour worth of exposures.

Florence animated Gif

Radar observations indicate it has two small moons in orbit around it.


Image via NASA/JPL Center for Near-Earth Object Studies.
Published in Solar System Objects
Wednesday, 03 May 2017 15:55

Asteroid 2014 JO25 Close Approach

On April 19th asteroid 2014 JO25 made its closest approach to Earth at a distance of about 1 million miles. The asteroid was discovered in May 2014 by astronomers using the Catalina Sky survey. Radar imaging of the asteroid shows it to be a contact binary asteroid. Each segment is about 2000 feet, with a rotation period of about 3.5 hours.

The following images were made the day after closest approach and are a composite showing the movement of the asteroid for period of about 45 minutes. Image file is about 12 megabytes, click the read more to view.

Published in Solar System Objects
Friday, 09 September 2016 16:50

Asteroid Cohnia

Asteroid Cohnia (almost) passes in front of a 13.5 magnitude star. I think I was just barely out of the occulation path. It was a good practice run, although much brighter objects would allow short exposures to determine the actual start and end times of the occulation. The asteroid at a magnitude of 14.7 and the star at 13.5 are much too dim for my setup for accurate timings.

Taken with the 80 mm refractor with Luminance filter over about 30 minutes of time.

Published in Solar System Objects