A newly discovered asteroid designated 2017 SM2 flew past Earth at 0.81 LD (~311 040 km / 193 271 miles) on September 20, 2017. This is the 30th known asteroid to flyby Earth within 1 LD since the start of the year and the second within the past 7 days, according to data available at CNEOS on September 20, 2017.
Asteroid 2017 SM2 belongs to the Apollo group of Asteroids. It was first observed at ATLAS-MLO, Mauna Loa on September 17, 2017.
Its estimated size is between 8.9 and 20 m (29 and 65 feet) and it flew past Earth at a speed (relative to the Earth) of 8.49 km/s at 07:34 UTC (± 1 minute) on September 20.
This is the 30th known near-Earth asteroid to flyby Earth within 1 LD since the start of the year and the second (after 2017 SQ2) within the past 7 days, according to data available at CNEOS on September 20, 2017. You can find them in our Near-Earth Objects category. It might also be interesting to compare what you find there with our reports of all notable bright fireballs around the globe. You can find that in our Meteor Activity category.
The closest one (2017 GM) flew past Earth at just 0.04 LD (~15 360 / 9 544 miles) on April 4. Its estimated diameter is between 2.8 and 6.3 m (9 and 20 feet).
The largest so far was 2017 QP1 with an estimated diameter of 37 to 83 m (121 to 272 feet). It flew past Earth at 0.16 LD (~61 440 km / 38 177 miles) on August 14.
As of September 16, there are 16 675 known near-Earth objects. Of them, 16 569 are near-Earth asteroids.
Featured image: The green line indicates the object's apparent motion relative to the Earth, and the bright green marks are the object's location at approximately one-hour intervals. The Moon's orbit is gray. The blue arrow points in the direction of Earth's motion and the yellow arrow points toward the Sun. Credit: Minor Planet Center