1998 HH49

On 17 October 2023 a boulder of approximately 250m in diameter 'skimmed' past the Earth (officially the diameter is estimated at 144 to 322m). Fortunately, the object missed us last night by a distance of roughly 1.2 million kilometres, just over three times the distance from the Earth to the Moon. At the time of the recording, the distance to 1998 HH49 had increased to approximately one and a half million kilometres, while being just en route from the constellation Aquarius to Pisces.

The asteroid is one of the 18232 Apollo-class Asteroids, meaning it is an object that crosses Earth's orbit. 1998 HH49 orbits the Sun for 705 days (about two years) with an orbital speed of approximately 15 km/s (with variations of approximately 4 km/s). Due to the short distance to Earth, the apparent speed was approximately 21 arc seconds per minute, which is clearly visible in the star streaks in the photo, which was exposed for 60 seconds.

Recording in a single sub of 60s around 19:28:14UTC with the SkyWatcher Esprit 150ED, ZWO ASI1600MM Pro Cool and ZWO luminance filter. Prior to the recording, the track parameters were programmed in the 10Micron GM3000HPS mount, making it possible to take this image unguided.

Click here for the full image.