Monday, June 11, 2018

Potentially Hazardous Asteroid 2018 EJ4 Flies by Earth

A potentially hazardous asteroid (PHA), known as 2018 EJ4, passed by the Earth on Sunday, June 10, at 19:16 UTC. The object missed our planet with a relative velocity of 6.2 km/s at a safe distance of about 5.56 lunar distances (LD), or 2.14 million kilometers.

2018 EJ4 is an Amor-type asteroid detected March 13, 2018 by the Mount Lemmon Survey (MLS) on October 6, 2008. MLS utilizes a 1.52 m cassegrain reflector telescope at Mount Lemmon Observatory in Arizona. It is one of the most prolific surveys when it comes to discovering new near-Earth objects (NEOs). So far, it has detected more than 50,000 minor planets.

According to astronomers, 2018 EJ4 has an absolute magnitude of 21.3. The object orbits the Sun every 513 days at a distance of about 1.25 AU from it.

Next close approach of this asteroid to Earth will occur on December 9, 2021, at a much larger distance of about 198 LD (76 million kilometers).

On June 11, there were nearly 2,000 PHAs detected, however none of them is on a collision course with our planet. PHAs are asteroids larger than 100 meters that can come closer to Earth than 19.5 LD.

To date, astronomers have discovered more than 18,300 NEOs. Since the beginning of this year, 790 such objects were detected.


  1. It is great that you describe such things.

    1. I used telescope Celestron SC 203/2000mm @ f/6.3, GoTo mount and DSLR Nikon D5200 (ISO 6400, 30 seconds) for 30 images of NEA 2018 EJ4.
      Date and time: 6 June 2018, 21:57 - 22:58 UT.
      Magnitude: 14,5